/******************************************************************************
                __               ____                __
               / /   ___  ____ _/ __/_____________ _/ /__
              / /   / _ \/ __ `/ /_/ ___/ ___/ __ `/ / _ \
             / /___/  __/ /_/ / __(__  ) /__/ /_/ / /  __/
            /_____/\___/\__,_/_/ /____/\___/\__,_/_/\___/

    (C)opyright 2025-2026, Leafscale, LLC -  https://www.leafscale.com

    Project: zyginit
   Filename: ui.reef
    Authors: Chris Tusa <chris.tusa@leafscale.com>
    License: <see LICENSE file included with this source code>
Description: Unified visual rendering: palette, glyphs, sigil, rolling tape, divider gauge, spinner, final cards.
     
******************************************************************************/

module ui

import core.str as str
import sys.env as env
import sys.process as process
import time.time as time
import version

export
    fn MODE_PLAIN(): int
    fn MODE_RICH_ASCII(): int
    fn MODE_RICH_16(): int
    fn MODE_RICH_TRUE(): int
    proc ui_init(rich_mode: int)
    proc ui_detect_winsize()
    fn ui_mode(): int
    fn ui_runlevel(): string
    fn ui_demo(scenario: string): int
    fn detect_rich_mode(): int
    fn detect_rich_mode_for_main(): int
    fn paint(token: string, text: string): string
    fn glyph_ok(): string
    fn glyph_fail(): string
    fn glyph_pending(): string
    fn glyph_starting(): string
    fn sigil(): string
    proc ui_boot_start(num_svc: int, num_tiers: int, runlevel: string)
    proc ui_tier_start(tier: int)
    proc ui_tier_done(tier: int)
    proc ui_event_started(name: string, dur_ms: int)
    proc ui_event_failed(name: string, exit_code: int, dur_ms: int)
    proc ui_event_starting(name: string)
    proc ui_event_stopping(name: string)
    proc ui_event_skipped(name: string, reason: string)
    proc ui_tick()
    fn ui_spinner_frame(reverse: bool): string
    fn fmt_divider_gauge(done: int, total: int): string
    type BootStats
    proc ui_boot_complete(stats: BootStats)
    proc ui_shutdown_start(reason: string)
    proc ui_event_stopped(name: string, dur_ms: int)
    proc ui_shutdown_complete(reason: string, elapsed_ms: int)
    fn pad_right(s: string, n: int): string
    fn make_divider(): string
    proc ui_set_mode(m: int)
    fn zyginit_monotonic_ms(): int
end export

type BootStats = struct
    elapsed_ms: int
    online: int
    failed: int
    skipped: int
    slowest: [string]
    slowest_count: int
end BootStats

// Render modes. Decided once at startup by ui_init().
fn MODE_PLAIN(): int        return 0   end MODE_PLAIN
fn MODE_RICH_ASCII(): int   return 1   end MODE_RICH_ASCII
fn MODE_RICH_16(): int      return 2   end MODE_RICH_16
fn MODE_RICH_TRUE(): int    return 3   end MODE_RICH_TRUE

mut g_mode: int = 0
mut g_failed: bool = false   // set if write() to /dev/console errors

// Declared here (before TAPE_HEIGHT) so the C prototype is emitted before
// its first use; also appears grouped with the other tape externs below.
extern "C" fn zyginit_tape_slots(): int

// Dynamic screen size — populated by ui_detect_winsize(), called from
// main.reef after setup_pid1_console() so /dev/console is on fd 1.
// Safe defaults (80x25) used when TIOCGWINSZ fails (Linux dev builds,
// pipes, integration tests with ZYGINIT_FORCE_80x25=1).
mut g_screen_rows: int = 25
mut g_screen_cols: int = 80
mut g_tape_height: int = 12
mut g_line_width: int = 78

fn TAPE_HEIGHT(): int return g_tape_height end TAPE_HEIGHT
fn LINE_WIDTH(): int  return g_line_width  end LINE_WIDTH

mut g_phase: string = ""
mut g_runlevel: string = ""
mut g_num_svc: int = 0
mut g_num_tiers: int = 0
mut g_cur_tier: int = 0
mut g_done: int = 0
mut g_failed_count: int = 0
mut g_skipped: int = 0
mut g_failed_first: string = ""
mut g_failed_first_exit: int = 0
mut g_boot_start_ms: int = 0
mut g_shutdown_reason: string = ""

// Spinner state
mut g_tick: int = 0

// Tape state counters. The backing arrays live in helpers.c (C static buffers)
// to avoid Reef's module-level new[] limitation (Reef emits GCC statement-expr
// initializers which are invalid as C static initializers).
mut g_tape_head: int = 0
mut g_tape_count: int = 0

extern "C" fn zyginit_isatty(fd: int): int
extern "C" fn zyginit_esc_str(): string
extern "C" fn zyginit_monotonic_ms(): int
extern "C" fn zyginit_tape_slots(): int
extern "C" proc zyginit_tape_clear()
extern "C" proc zyginit_tape_set(slot: int, elapsed: int, glyph: string, svc_name: string, note: string, active_flag: int)
extern "C" fn zyginit_tape_get_elapsed(slot: int): int
extern "C" fn zyginit_tape_get_glyph(slot: int): string
extern "C" fn zyginit_tape_get_name(slot: int): string
extern "C" fn zyginit_tape_get_note(slot: int): string
extern "C" fn zyginit_tape_get_active(slot: int): int
extern "C" proc zyginit_tape_set_active(slot: int, active_flag: int)
extern "C" proc zyginit_tape_set_glyph(slot: int, glyph: string)
extern "C" proc zyginit_tape_set_note(slot: int, note: string)
extern "C" fn zyginit_get_winsize(fd: int, out_rows: [int], out_cols: [int]): int

fn N_FRAMES(): int return 4 end N_FRAMES

// Return the current spinner frame character.
// Forward (starting): cycles / - \ |  with increasing g_tick
// Reverse (stopping): cycles | \ - /  with increasing g_tick (unwinds)
fn ui_spinner_frame(reverse: bool): string
    let i = g_tick % N_FRAMES()
    if reverse
        let r = (N_FRAMES() - 1) - i
        if r == 0  return "/"  end if
        if r == 1  return "-"  end if
        if r == 2  return "\\"  end if
        return "|"
    end if
    if i == 0  return "/"  end if
    if i == 1  return "-"  end if
    if i == 2  return "\\"  end if
    return "|"
end ui_spinner_frame

// Pure terminal capability detector (no PID check, no isatty check).
// Inspects only env vars and TERM. Use this from --ui-demo and snapshot tests.
// Production callers (main.reef boot path) should use
// detect_rich_mode_for_main() — it adds the PID-1 and isatty guards.
fn detect_rich_mode(): int
    if env.has_env("ZYGINIT_NO_UI")     return MODE_PLAIN()      end if
    if env.has_env("NO_COLOR")          return MODE_PLAIN()      end if
    let term = env.get_env_or("TERM", "")
    if term == "dumb"                   return MODE_PLAIN()      end if
    if env.has_env("ZYGINIT_ASCII")     return MODE_RICH_ASCII() end if
    if term == "sun"                    return MODE_RICH_16()    end if
    if term == "vt100"                  return MODE_RICH_16()    end if
    if term == "vt220"                  return MODE_RICH_16()    end if
    if term == "sun-color"              return MODE_RICH_TRUE()  end if
    if str.index_of(term, "256color") >= 0
        return MODE_RICH_TRUE()
    end if
    // Hammerhead UEFI framebuffer: kernel doesn't set TERM but tem
    // supports full ANSI/CSI/truecolor. Default to truecolor when
    // we have no TERM hint.
    if str.length(term) == 0            return MODE_RICH_TRUE()  end if
    // Anything else: safe 16-color baseline.
    return MODE_RICH_16()
end detect_rich_mode

// PID-1-aware, tty-aware wrapper around detect_rich_mode.
// Adds: non-PID-1 instances always emit plain; non-tty stdout always emits plain.
// Call this from main.reef boot path; call detect_rich_mode() for tests/demo.
fn detect_rich_mode_for_main(): int
    // Hard overrides
    if env.has_env("ZYGINIT_NO_UI")  return MODE_PLAIN()  end if
    if env.has_env("NO_COLOR")       return MODE_PLAIN()  end if
    // Production gates
    if process.getpid() != 1         return MODE_PLAIN()  end if
    if zyginit_isatty(1) == 0        return MODE_PLAIN()  end if
    // TERM-driven mode
    let term = env.get_env_or("TERM", "")
    if term == "dumb"                return MODE_PLAIN()      end if
    if env.has_env("ZYGINIT_ASCII")  return MODE_RICH_ASCII() end if
    if term == "sun"                 return MODE_RICH_16()    end if
    if term == "vt100"               return MODE_RICH_16()    end if
    if term == "vt220"               return MODE_RICH_16()    end if
    if term == "sun-color"           return MODE_RICH_TRUE()  end if
    if str.index_of(term, "256color") >= 0
        return MODE_RICH_TRUE()
    end if
    // Hammerhead UEFI framebuffer: kernel doesn't set TERM but tem
    // supports full ANSI/CSI/truecolor. Default to truecolor when we
    // have a tty but no TERM hint.
    if str.length(term) == 0         return MODE_RICH_TRUE()  end if
    // Anything else: safe 16-color baseline.
    return MODE_RICH_16()
end detect_rich_mode_for_main

// SGR escape sequences. ESC char via C helper (Reef lexer has no \x escapes).
// esc_reset returns the SGR reset sequence "\e[0m".
fn esc_reset(): string
    return str.concat(zyginit_esc_str(), "[0m")
end esc_reset

// 16-color foreground codes.
fn sgr_steel(): string  return str.concat(zyginit_esc_str(), "[37m")   end sgr_steel
fn sgr_teal(): string   return str.concat(zyginit_esc_str(), "[36m")   end sgr_teal
fn sgr_ok(): string     return str.concat(zyginit_esc_str(), "[32m")   end sgr_ok
fn sgr_warn(): string   return str.concat(zyginit_esc_str(), "[33m")   end sgr_warn
fn sgr_fail(): string   return str.concat(zyginit_esc_str(), "[31m")   end sgr_fail
fn sgr_mute(): string   return str.concat(zyginit_esc_str(), "[2m")    end sgr_mute

// Truecolor foreground codes.
fn sgr_steel_true(): string return str.concat(zyginit_esc_str(), "[38;2;110;123;139m")  end sgr_steel_true
fn sgr_teal_true(): string  return str.concat(zyginit_esc_str(), "[38;2;0;106;111m")    end sgr_teal_true
fn sgr_ok_true(): string    return str.concat(zyginit_esc_str(), "[38;2;46;139;87m")    end sgr_ok_true
fn sgr_warn_true(): string  return str.concat(zyginit_esc_str(), "[38;2;255;191;0m")    end sgr_warn_true
fn sgr_fail_true(): string  return str.concat(zyginit_esc_str(), "[38;2;200;32;31m")    end sgr_fail_true

// Wrap text in the given palette token, honoring g_mode.
fn paint(token: string, text: string): string
    if g_mode == MODE_PLAIN()  return text  end if
    mut on = ""
    if g_mode == MODE_RICH_TRUE()
        if token == "frame"       on = sgr_steel_true()
        elif token == "accent"    on = sgr_teal_true()
        elif token == "ok"        on = sgr_ok_true()
        elif token == "warn"      on = sgr_warn_true()
        elif token == "fail"      on = sgr_fail_true()
        elif token == "mute"      on = sgr_mute()
        end if
    else
        if token == "frame"       on = sgr_steel()
        elif token == "accent"    on = sgr_teal()
        elif token == "ok"        on = sgr_ok()
        elif token == "warn"      on = sgr_warn()
        elif token == "fail"      on = sgr_fail()
        elif token == "mute"      on = sgr_mute()
        end if
    end if
    return str.concat(str.concat(on, text), esc_reset())
end paint

// Glyphs. Selected by g_mode.
fn glyph_ok(): string
    if g_mode == MODE_RICH_ASCII() return "#"   end if
    if g_mode == MODE_PLAIN()      return "ok"  end if
    return "●"
end glyph_ok

fn glyph_fail(): string
    if g_mode == MODE_RICH_ASCII() return "X"    end if
    if g_mode == MODE_PLAIN()      return "fail" end if
    return "✕"
end glyph_fail

fn glyph_pending(): string
    if g_mode == MODE_RICH_ASCII() return "."       end if
    if g_mode == MODE_PLAIN()      return "pending" end if
    return "·"
end glyph_pending

fn glyph_starting(): string
    if g_mode == MODE_RICH_ASCII() return "o"        end if
    if g_mode == MODE_PLAIN()      return "starting" end if
    return "◉"
end glyph_starting

// Sigil: "[Z]" colored c.accent in rich modes.
fn sigil(): string
    return paint("accent", "[Z]")
end sigil

// Plain-mode line: "  <elapsed-s>  <level>  <event>     <name>  [k=v ...]"
fn fmt_plain_event(elapsed_ms: int, level: string, event: string,
                   name: string, kv: string): string
    let secs = int_to_str(elapsed_ms / 1000)
    // centiseconds: truncate the within-second remainder to 0-99 (2 digits)
    let frac = int_to_str((elapsed_ms % 1000) / 10)
    mut pad = ""
    if str.length(frac) < 2  pad = "0"  end if
    mut line = str.concat("  ", secs)
    line = str.concat(line, ".")
    line = str.concat(line, pad)
    line = str.concat(line, frac)
    line = str.concat(line, "  ")
    line = str.concat(line, level)
    line = str.concat(line, "  ")
    line = str.concat(line, event)
    line = str.concat(line, "  ")
    line = str.concat(line, name)
    if str.length(kv) > 0
        line = str.concat(line, "  ")
        line = str.concat(line, kv)
    end if
    return line
end fmt_plain_event

proc tape_push(elapsed_ms: int, glyph: string, name: string, note: string, active_flag: int)
    let slot = g_tape_head % TAPE_HEIGHT()
    zyginit_tape_set(slot, elapsed_ms, glyph, name, note, active_flag)
    g_tape_head = g_tape_head + 1
    if g_tape_count < TAPE_HEIGHT()
        g_tape_count = g_tape_count + 1
    end if
end tape_push

fn fmt_tape_row(row_elapsed_ms: int, row_glyph: string, row_name: string, row_note: string): string
    let secs = row_elapsed_ms / 1000
    let frac = (row_elapsed_ms % 1000) / 10
    mut sf = int_to_str(frac)
    if str.length(sf) < 2  sf = str.concat("0", sf)  end if
    let elapsed = str.concat(str.concat(int_to_str(secs), "."), sf)
    mut pad = ""
    let pad_n = 6 - str.length(elapsed)
    mut i = 0
    while i < pad_n
        pad = str.concat(pad, " ")
        i = i + 1
    end while
    mut row = str.concat(pad, elapsed)
    row = str.concat(row, "  ")
    row = str.concat(row, row_glyph)
    row = str.concat(row, "  ")
    row = str.concat(row, row_name)
    if str.length(row_note) > 0
        row = str.concat(row, "  ")
        row = str.concat(row, paint("mute", str.concat(str.concat("(", row_note), ")")))
    end if
    return row
end fmt_tape_row

fn make_divider(): string
    mut div = ""
    mut k = 0
    let dlen = g_line_width - 16
    while k < dlen
        div = str.concat(div, "─")
        k = k + 1
    end while
    return div
end make_divider

fn fmt_header(elapsed_ms: int): string
    let secs = elapsed_ms / 1000
    let frac = (elapsed_ms % 1000) / 100
    let elapsed = str.concat(str.concat(int_to_str(secs), "."), str.concat(int_to_str(frac), "s"))
    let phase_label = g_runlevel
    mut out = str.concat("  ", sigil())
    out = str.concat(out, str.concat(" zyginit ", str.concat(version.VERSION(), " · ")))
    out = str.concat(out, paint("frame", phase_label))
    let boot_visually_done = (g_phase == "boot") and
                             ((g_done + g_skipped + g_failed_count) >= g_num_svc) and
                             (g_num_svc > 0)
    if not boot_visually_done
        out = str.concat(out, "   ")
        out = str.concat(out, paint("accent", str.concat("elapsed ", elapsed)))
    end if
    out = str.concat(out, "\n  ")
    out = str.concat(out, paint("frame",
        str.concat(str.concat(int_to_str(g_num_svc), " services · tier "),
        str.concat(str.concat(int_to_str(g_cur_tier), " · "),
        str.concat(str.concat(int_to_str(g_done), " done · "),
        str.concat(str.concat(int_to_str(g_failed_count), " failed · "),
        str.concat(int_to_str(g_skipped), " skipped")))))))
    out = str.concat(out, "\n  ")
    if g_failed_count == 0
        out = str.concat(out, paint("mute", "failed: none"))
    elif g_failed_count == 1
        out = str.concat(out, paint("fail",
            str.concat(str.concat("failed: ", g_failed_first),
            str.concat("  exit=", int_to_str(g_failed_first_exit)))))
    else
        out = str.concat(out, paint("fail",
            str.concat(str.concat("failed: ", int_to_str(g_failed_count)),
            " services")))
    end if
    out = str.concat(out, "\n  ")
    out = str.concat(out, fmt_divider_gauge(g_done + g_skipped, g_num_svc))
    return out
end fmt_header

// Render the boot/shutdown header's bottom rule as a divider with an
// embedded progress gauge. Replaces make_divider() in fmt_header's
// trailing rule and superseded fmt_progress_bar() (now removed) in
// render_boot_screen. Total visual width =
// g_line_width - 16 (matches make_divider). Brackets + 26-cell inner
// content + equal lpad/rpad of dashes. Narrow-terminal fallback drops
// the brackets and shows just "── NN% ──".
fn fmt_divider_gauge(done: int, total: int): string
    if g_mode == MODE_PLAIN()  return ""  end if

    let total_width = g_line_width - 16
    let bar_width = 20
    let inner_width = 26              // bar(20) + "  "(2) + "NNN%"(4)
    let bracket_width = inner_width + 2   // 28: '[' + inner + ']'

    mut filled = 0
    if total > 0
        filled = (done * bar_width) / total
    end if
    if filled > bar_width  filled = bar_width  end if
    if filled < 0  filled = 0  end if

    mut pct = 0
    if total > 0
        pct = (done * 100) / total
    end if
    if pct > 100  pct = 100  end if
    if pct < 0  pct = 0  end if

    // pct_field: right-aligned 3 cells + '%' = 4 cells. E.g. "  3%", " 31%", "100%".
    let pct_str = int_to_str(pct)
    let pct_len = str.length(pct_str)
    mut pct_field = ""
    mut pp = 0
    while pp < (3 - pct_len)
        pct_field = str.concat(pct_field, " ")
        pp = pp + 1
    end while
    pct_field = str.concat(pct_field, pct_str)
    pct_field = str.concat(pct_field, "%")

    // Narrow-terminal fallback: not enough room for brackets + padding.
    if total_width < bracket_width + 2
        // Emit "── NN% ──" centered in total_width.
        let label = str.concat(" ", str.concat(pct_field, " "))
        let label_len = 1 + 4 + 1   // " " + "NNN%" + " "
        mut pad = 0
        if total_width > label_len
            pad = total_width - label_len
        end if
        let lpad_n = pad / 2
        let rpad_n = pad - lpad_n
        mut out = ""
        mut a = 0
        while a < lpad_n
            out = str.concat(out, "─")
            a = a + 1
        end while
        out = str.concat(out, label)
        a = 0
        while a < rpad_n
            out = str.concat(out, "─")
            a = a + 1
        end while
        return paint("accent", out)
    end if

    // Full layout: lpad + '[' + bar + "  " + pct_field + ']' + rpad
    let pad_total = total_width - bracket_width
    let lpad_n = pad_total / 2
    let rpad_n = pad_total - lpad_n

    // Build the bar. Painting per-cell to support per-mode chars.
    mut bar = ""
    mut i = 0
    while i < bar_width
        if g_mode == MODE_RICH_ASCII()
            if i < filled
                bar = str.concat(bar, "#")
            else
                bar = str.concat(bar, " ")
            end if
        else
            if i < filled
                bar = str.concat(bar, paint("accent", "█"))
            else
                bar = str.concat(bar, paint("mute", "░"))
            end if
        end if
        i = i + 1
    end while

    // Assemble. Brackets, pct, and pad chars all painted "accent".
    mut out = ""
    mut j = 0
    while j < lpad_n
        out = str.concat(out, "─")
        j = j + 1
    end while
    out = paint("accent", out)
    out = str.concat(out, paint("accent", "["))
    out = str.concat(out, bar)
    out = str.concat(out, paint("accent", "  "))
    out = str.concat(out, paint("accent", pct_field))
    out = str.concat(out, paint("accent", "]"))
    mut rpad = ""
    j = 0
    while j < rpad_n
        rpad = str.concat(rpad, "─")
        j = j + 1
    end while
    out = str.concat(out, paint("accent", rpad))
    return out
end fmt_divider_gauge


// Render a single tape row, overriding the stored glyph with the current
// spinner frame when the row's active flag indicates a starting or stopping
// transition (active==1 = forward spinner, active==2 = reverse spinner).
fn fmt_tape_row_at(slot: int): string
    let elapsed_ms = zyginit_tape_get_elapsed(slot)
    let name = zyginit_tape_get_name(slot)
    let note = zyginit_tape_get_note(slot)
    let stored_glyph = zyginit_tape_get_glyph(slot)
    let row_active = zyginit_tape_get_active(slot)
    mut glyph = stored_glyph
    if row_active == 1
        glyph = paint("warn", ui_spinner_frame(false))
    elif row_active == 2
        glyph = paint("warn", ui_spinner_frame(true))
    end if
    return fmt_tape_row(elapsed_ms, glyph, name, note)
end fmt_tape_row_at

// Scan tape for any slot with a non-zero active flag (i.e., a spinner is live).
fn has_active_tape_row(): bool
    mut i = 0
    while i < g_tape_count
        let logical = g_tape_head - 1 - i
        mut slot = logical % TAPE_HEIGHT()
        if slot < 0
            slot = slot + TAPE_HEIGHT()
        end if
        if zyginit_tape_get_active(slot) != 0
            return true
        end if
        i = i + 1
    end while
    return false
end has_active_tape_row

// Find the most-recently-pushed tape slot with a non-zero active flag and
// whose name matches `name`. Returns the slot index or -1 if not found.
fn tape_find_active_by_name(name: string): int
    if g_tape_count == 0
        return 0 - 1
    end if
    mut i = 0
    while i < g_tape_count
        let logical = g_tape_head - 1 - i
        mut slot = logical % TAPE_HEIGHT()
        if slot < 0
            slot = slot + TAPE_HEIGHT()
        end if
        if zyginit_tape_get_active(slot) != 0
            if zyginit_tape_get_name(slot) == name
                return slot
            end if
        end if
        i = i + 1
    end while
    return 0 - 1
end tape_find_active_by_name

fn render_boot_screen(elapsed_ms: int): string
    if g_mode == MODE_PLAIN()
        return ""
    end if
    mut out = str.concat(fmt_header(elapsed_ms), "\n")
    let start = g_tape_head - g_tape_count
    mut i = 0
    while i < TAPE_HEIGHT()
        if i < g_tape_count
            let slot = (start + i) % TAPE_HEIGHT()
            out = str.concat(out, fmt_tape_row_at(slot))
        end if
        if i < (TAPE_HEIGHT() - 1)
            out = str.concat(out, "\n")
        end if
        i = i + 1
    end while
    // No trailing newline: total height is exactly g_screen_rows. A trailing
    // \n would advance the cursor past the bottom edge and scroll the [Z]
    // banner off the top of the screen. The progress gauge lives in the
    // header rule (see fmt_divider_gauge), not on the last row.
    return out
end render_boot_screen

// Advance the tick counter and, if in rich mode with an active spinner, redraw.
proc ui_tick()
    g_tick = g_tick + 1
    if g_mode == MODE_PLAIN()  return  end if
    if not has_active_tape_row()  return  end if
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
          str.concat(zyginit_esc_str(), "[H")))
    print(render_boot_screen(elapsed))
end ui_tick

// Rich-mode-only redraw. Plain mode emits its own line before calling this.
proc emit_redraw(elapsed_ms: int)
    if g_mode == MODE_PLAIN()  return  end if
    print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
          str.concat(zyginit_esc_str(), "[H")))
    print(render_boot_screen(elapsed_ms))
end emit_redraw

proc ui_boot_start(num_svc: int, num_tiers: int, runlevel: string)
    g_phase = "boot"
    g_runlevel = runlevel
    g_num_svc = num_svc
    g_num_tiers = num_tiers
    g_cur_tier = 0
    g_done = 0
    g_failed_count = 0
    g_skipped = 0
    g_failed_first = ""
    g_failed_first_exit = 0
    g_tape_head = 0
    g_tape_count = 0
    zyginit_tape_clear()
    g_boot_start_ms = zyginit_monotonic_ms()
end ui_boot_start

proc ui_tier_start(tier: int)
    g_cur_tier = tier
end ui_tier_start

proc ui_tier_done(tier: int)
    // header repaints happen via emit_redraw on next event/tick
end ui_tier_done

// dur_ms: service's own runtime (from supervisor). Reserved for future
// use (Task 6 spinner display); the tape currently shows wall-clock
// elapsed since boot, not per-service duration.
proc ui_event_started(name: string, dur_ms: int)
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    g_done = g_done + 1
    let slot = tape_find_active_by_name(name)
    if slot >= 0
        // Update the existing active row in place
        zyginit_tape_set_glyph(slot, paint("ok", glyph_ok()))
        zyginit_tape_set_note(slot, "")
        zyginit_tape_set_active(slot, 0)
    else
        // No prior starting row — push a fresh static row
        tape_push(elapsed, paint("ok", glyph_ok()), name, "", 0)
    end if
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(elapsed, "info", "started", name, ""))
    else
        emit_redraw(elapsed)
    end if
end ui_event_started

// dur_ms: service's own runtime (from supervisor). Reserved for future
// use (Task 6 spinner display); the tape currently shows wall-clock
// elapsed since boot, not per-service duration.
proc ui_event_failed(name: string, exit_code: int, dur_ms: int)
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    g_done = g_done + 1
    g_failed_count = g_failed_count + 1
    if g_failed_count == 1
        g_failed_first = name
        g_failed_first_exit = exit_code
    end if
    let exit_kv = str.concat("exit=", int_to_str(exit_code))
    let slot = tape_find_active_by_name(name)
    if slot >= 0
        zyginit_tape_set_glyph(slot, paint("fail", glyph_fail()))
        zyginit_tape_set_note(slot, exit_kv)
        zyginit_tape_set_active(slot, 0)
    else
        tape_push(elapsed, paint("fail", glyph_fail()), name, exit_kv, 0)
    end if
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(elapsed, "err", "failed", name, exit_kv))
    else
        emit_redraw(elapsed)
    end if
end ui_event_failed

// Called when a service is transitioning to started (forward spinner visible).
proc ui_event_starting(name: string)
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    // active=1: forward spinner (starting)
    tape_push(elapsed, paint("warn", ui_spinner_frame(false)), name, "", 1)
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(elapsed, "info", "starting", name, ""))
    else
        emit_redraw(elapsed)
    end if
end ui_event_starting

// Called when a service is transitioning to stopped (reverse spinner visible).
proc ui_event_stopping(name: string)
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    // active=2: reverse spinner (stopping)
    tape_push(elapsed, paint("warn", ui_spinner_frame(true)), name, "", 2)
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(elapsed, "info", "stopping", name, ""))
    else
        emit_redraw(elapsed)
    end if
end ui_event_stopping

// Called when a service's [condition] block fails and the service is skipped
// (STATE_SKIPPED). No process is ever forked; the service is counted as done
// for progress purposes but not as online or failed.
proc ui_event_skipped(name: string, reason: string)
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    g_skipped = g_skipped + 1
    let note = str.concat("skipped: ", reason)
    tape_push(elapsed, paint("mute", glyph_pending()), name, note, 0)
    if g_mode == MODE_PLAIN()
        let kv = str.concat("reason=", reason)
        println(fmt_plain_event(elapsed, "info", "skipped", name, kv))
    else
        emit_redraw(elapsed)
    end if
end ui_event_skipped

proc ui_init(rich_mode: int)
    g_mode = rich_mode
    g_failed = false
end ui_init

// Detect terminal size via TIOCGWINSZ and update g_tape_height / g_line_width.
// Called from main.reef after setup_pid1_console() (so fd 1 = /dev/console)
// and before ui_boot_start().
// When ZYGINIT_FORCE_80x25 is set (integration / snapshot tests), lock to
// 80x25 so snapshot output is deterministic regardless of the host terminal.
proc ui_detect_winsize()
    if env.has_env("ZYGINIT_FORCE_80x25")
        g_screen_rows = 25
        g_screen_cols = 80
    else
        let rows = new [int](1)
        let cols = new [int](1)
        rows[0] = 25
        cols[0] = 80
        if zyginit_get_winsize(1, rows, cols) == 0
            g_screen_rows = rows[0]
            g_screen_cols = cols[0]
        end if
    end if
    // Tape height = screen rows - (header 4 rows including gauge divider).
    // Gauge lives inside the header, not on a separate trailing row.
    g_tape_height = g_screen_rows - 4
    if g_tape_height < 4
        g_tape_height = 4
    end if
    if g_tape_height > 32
        g_tape_height = 32
    end if
    // Line width = cols - 2 (1-char margin each side)
    g_line_width = g_screen_cols - 2
    if g_line_width < 40
        g_line_width = 40
    end if
end ui_detect_winsize

fn ui_mode(): int
    return g_mode
end ui_mode

fn ui_runlevel(): string
    return g_runlevel
end ui_runlevel

proc ui_set_mode(m: int)
    g_mode = m
end ui_set_mode

proc ui_boot_complete(stats: BootStats)
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(stats.elapsed_ms, "info", "boot_complete",
                "summary", str.concat(str.concat("online=", int_to_str(stats.online)),
                           str.concat(str.concat(" failed=", int_to_str(stats.failed)),
                                      str.concat(" skipped=", int_to_str(stats.skipped))))))
        return
    end if
    // Clear screen, paint final card.
    print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
          str.concat(zyginit_esc_str(), "[H")))
    let secs = stats.elapsed_ms / 1000
    let frac = (stats.elapsed_ms % 1000) / 100
    let elapsed = str.concat(str.concat(int_to_str(secs), "."),
                             str.concat(int_to_str(frac), "s"))
    let summary_count = int_to_str(stats.online + stats.failed + stats.skipped)
    mut out = str.concat("  ", sigil())
    out = str.concat(out, str.concat(" zyginit ", str.concat(version.VERSION(), " · ")))
    out = str.concat(out, paint("frame", g_runlevel))
    out = str.concat(out, "   ")
    out = str.concat(out, paint("accent", str.concat("boot ", elapsed)))
    out = str.concat(out, "\n")
    out = str.concat(out, "  ")
    out = str.concat(out, paint("frame",
        str.concat(str.concat(summary_count, " services — "),
        str.concat(str.concat(int_to_str(stats.online), " online, "),
        str.concat(str.concat(int_to_str(stats.failed), " failed, "),
        str.concat(int_to_str(stats.skipped), " skipped"))))))
    out = str.concat(out, "\n\n")
    if stats.failed == 0
        out = str.concat(out, "  ")
        out = str.concat(out, paint("ok", "all services online"))
        out = str.concat(out, "\n")
    elif stats.failed == 1
        out = str.concat(out, "  ")
        out = str.concat(out, paint("fail",
            str.concat(str.concat("failed: ", g_failed_first),
            str.concat("  exit=", int_to_str(g_failed_first_exit)))))
        out = str.concat(out, "\n")
        out = str.concat(out, "      ")
        out = str.concat(out, paint("accent",
            str.concat("→ zygctl log ", g_failed_first)))
        out = str.concat(out, paint("mute", "    to see why"))
        out = str.concat(out, "\n")
    else
        out = str.concat(out, "  ")
        out = str.concat(out, paint("fail",
            str.concat(str.concat("failed: ", int_to_str(stats.failed)), " services")))
        out = str.concat(out, "\n")
        out = str.concat(out, "      ")
        out = str.concat(out, paint("accent", "→ zygctl status"))
        out = str.concat(out, paint("mute", "    to see them"))
        out = str.concat(out, "\n")
    end if
    out = str.concat(out, "  ")
    out = str.concat(out, paint("accent", make_divider()))
    out = str.concat(out, "\n")
    // Slowest line
    let slow_n = stats.slowest_count
    if slow_n > 0
        mut slow = "slowest:"
        mut i = 0
        mut max = slow_n
        if max > 3
            max = 3
        end if
        while i < max
            slow = str.concat(slow, "  ")
            slow = str.concat(slow, stats.slowest[i])
            i = i + 1
        end while
        out = str.concat(out, "  ")
        out = str.concat(out, paint("frame", slow))
        out = str.concat(out, "\n")
    end if
    print(out)
end ui_boot_complete

proc ui_shutdown_start(reason: string)
    g_phase = "shutdown"
    g_shutdown_reason = reason
    g_runlevel = str.concat("stopping for ", reason)
    g_done = 0
    g_failed_count = 0
    g_skipped = 0
    g_failed_first = ""
    g_failed_first_exit = 0
    g_tape_head = 0
    g_tape_count = 0
    g_boot_start_ms = zyginit_monotonic_ms()
end ui_shutdown_start

proc ui_event_stopped(name: string, dur_ms: int)
    let elapsed = zyginit_monotonic_ms() - g_boot_start_ms
    g_done = g_done + 1
    let slot = tape_find_active_by_name(name)
    if slot >= 0
        zyginit_tape_set_glyph(slot, paint("mute", glyph_pending()))
        zyginit_tape_set_note(slot, "")
        zyginit_tape_set_active(slot, 0)
    else
        tape_push(elapsed, paint("mute", glyph_pending()), name, "", 0)
    end if
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(elapsed, "info", "stopped", name, ""))
    else
        emit_redraw(elapsed)
    end if
end ui_event_stopped

proc ui_shutdown_complete(reason: string, elapsed_ms: int)
    if g_mode == MODE_PLAIN()
        println(fmt_plain_event(elapsed_ms, "info", "shutdown_complete",
                reason, str.concat("down=", int_to_str(g_done))))
        return
    end if
    print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
          str.concat(zyginit_esc_str(), "[H")))
    let secs = elapsed_ms / 1000
    let frac = (elapsed_ms % 1000) / 100
    let elapsed = str.concat(str.concat(int_to_str(secs), "."),
                             str.concat(int_to_str(frac), "s"))
    mut out = str.concat("  ", sigil())
    out = str.concat(out, str.concat(" zyginit ", str.concat(version.VERSION(), " · ")))
    out = str.concat(out, paint("frame", str.concat(reason, " complete")))
    out = str.concat(out, "   ")
    out = str.concat(out, paint("accent", str.concat(str.concat(reason, " "), elapsed)))
    out = str.concat(out, "\n  ")
    mut stat_str = "stopped cleanly"
    if g_failed_count > 0
        stat_str = str.concat(str.concat("stopped (", int_to_str(g_failed_count)), " force-killed)")
    end if
    out = str.concat(out, paint("frame",
        str.concat(str.concat(int_to_str(g_num_svc), " services "), stat_str)))
    out = str.concat(out, "\n  ")
    out = str.concat(out, paint("accent", make_divider()))
    out = str.concat(out, "\n  ")
    out = str.concat(out, paint("mute", "invoking uadmin(A_SHUTDOWN, AD_BOOT)"))
    out = str.concat(out, "\n")
    print(out)
end ui_shutdown_complete

// Scenario dispatcher for --ui-demo. Called from main.reef.
// Returns 0 on success, 1 if the scenario name is unknown.
fn ui_demo(scenario: string): int
    if scenario == "skeleton"
        println("ui.reef skeleton ok, mode=" + int_to_str(g_mode))
        return 0
    end if
    if scenario == "plain_boot"
        println(fmt_plain_event(40, "info", "started", "root-fs", ""))
        println(fmt_plain_event(120, "info", "started", "crypto", "dur_ms=80"))
        println(fmt_plain_event(310, "info", "started", "devfs", "dur_ms=190"))
        println(fmt_plain_event(5020, "err",  "failed",  "network", "exit=1 dur_ms=4023"))
        return 0
    end if
    if str.index_of(scenario, "detect_") == 0
        g_mode = detect_rich_mode()
        println("mode=" + int_to_str(g_mode))
        return 0
    end if
    if scenario == "palette_true" or scenario == "palette_16"
        g_mode = detect_rich_mode()
        println(paint("frame",  "frame text"))
        println(paint("accent", "accent text"))
        println(paint("ok",     "ok text"))
        println(paint("warn",   "warn text"))
        println(paint("fail",   "fail text"))
        println(paint("mute",   "mute text"))
        return 0
    end if
    if scenario == "glyphs_unicode" or scenario == "glyphs_ascii"
        g_mode = detect_rich_mode()
        println(glyph_ok() + " " + glyph_starting() + " " +
                glyph_fail() + " " + glyph_pending())
        return 0
    end if
    if scenario == "sigil_rich"
        g_mode = detect_rich_mode()
        println(sigil() + " zyginit " + version.VERSION())
        return 0
    end if
    if scenario == "boot_tape_rich" or scenario == "boot_tape_ascii" or scenario == "boot_tape_plain"
        g_mode = detect_rich_mode()
        ui_boot_start(17, 8, "multi-user")
        g_boot_start_ms = 0
        let names = new [string](9)
        names[0] = "root-fs"
        names[1] = "crypto"
        names[2] = "devfs"
        names[3] = "swap"
        names[4] = "filesystem"
        names[5] = "identity"
        names[6] = "sysconfig"
        names[7] = "dlmgmtd"
        names[8] = "network"
        let elapsed_seq = new [int](9)
        elapsed_seq[0] = 40
        elapsed_seq[1] = 160
        elapsed_seq[2] = 310
        elapsed_seq[3] = 490
        elapsed_seq[4] = 1040
        elapsed_seq[5] = 1080
        elapsed_seq[6] = 1360
        elapsed_seq[7] = 1550
        elapsed_seq[8] = 5020
        mut i = 0
        while i < 8
            g_done = g_done + 1
            tape_push(elapsed_seq[i], paint("ok", glyph_ok()), names[i], "", 0)
            i = i + 1
        end while
        g_failed_count = 1
        g_failed_first = "network"
        g_failed_first_exit = 1
        g_cur_tier = 5
        g_done = g_done + 1
        tape_push(5020, paint("fail", glyph_fail()), "network", "exit=1", 0)
        if g_mode == MODE_PLAIN()
            let lvls = new [string](9)
            let evs = new [string](9)
            let kvs = new [string](9)
            mut j = 0
            while j < 8
                lvls[j] = "info"
                evs[j] = "started"
                kvs[j] = ""
                j = j + 1
            end while
            lvls[8] = "err"
            evs[8] = "failed"
            kvs[8] = "exit=1"
            mut k = 0
            while k < 9
                println(fmt_plain_event(elapsed_seq[k], lvls[k], evs[k], names[k], kvs[k]))
                k = k + 1
            end while
        else
            print(render_boot_screen(5020))
        end if
        return 0
    end if
    if scenario == "progress_rich" or scenario == "progress_ascii"
        if scenario == "progress_ascii"
            g_mode = MODE_RICH_ASCII()
        else
            g_mode = detect_rich_mode()
            if g_mode == MODE_PLAIN()  g_mode = MODE_RICH_TRUE()  end if
        end if
        ui_detect_winsize()
        ui_boot_start(17, 8, "multi-user")
        g_done = 12
        g_failed_count = 1
        println(fmt_divider_gauge(g_done + g_skipped, g_num_svc))
        return 0
    end if
    if scenario == "progress_full"
        g_mode = detect_rich_mode()
        if g_mode == MODE_PLAIN()  g_mode = MODE_RICH_TRUE()  end if
        ui_detect_winsize()
        ui_boot_start(17, 8, "multi-user")
        g_done = 17
        println(fmt_divider_gauge(g_done + g_skipped, g_num_svc))
        return 0
    end if
    if scenario == "gauge_live_31" or scenario == "gauge_live_31_ascii"
        if scenario == "gauge_live_31_ascii"
            g_mode = MODE_RICH_ASCII()
        else
            g_mode = detect_rich_mode()
            if g_mode == MODE_PLAIN()  g_mode = MODE_RICH_TRUE()  end if
        end if
        ui_detect_winsize()
        println(fmt_divider_gauge(31, 100))
        return 0
    end if
    if scenario == "gauge_live_100"
        g_mode = detect_rich_mode()
        if g_mode == MODE_PLAIN()  g_mode = MODE_RICH_TRUE()  end if
        ui_detect_winsize()
        println(fmt_divider_gauge(100, 100))
        return 0
    end if
    if scenario == "gauge_live_0"
        g_mode = detect_rich_mode()
        if g_mode == MODE_PLAIN()  g_mode = MODE_RICH_TRUE()  end if
        ui_detect_winsize()
        println(fmt_divider_gauge(0, 100))
        return 0
    end if
    if scenario == "spinner_forward"
        g_mode = detect_rich_mode()
        mut i = 0
        while i < 8
            g_tick = i
            print(ui_spinner_frame(false))
            i = i + 1
        end while
        println("")
        return 0
    end if
    if scenario == "spinner_reverse"
        g_mode = detect_rich_mode()
        mut i = 0
        while i < 8
            g_tick = i
            print(ui_spinner_frame(true))
            i = i + 1
        end while
        println("")
        return 0
    end if
    if scenario == "spinner_in_tape"
        g_mode = detect_rich_mode()
        ui_boot_start(17, 8, "multi-user")
        g_boot_start_ms = 0
        tape_push(40, paint("ok", glyph_ok()), "root-fs", "", 0)
        tape_push(160, paint("ok", glyph_ok()), "crypto", "", 0)
        tape_push(310, paint("ok", glyph_ok()), "devfs", "", 0)
        g_done = 3
        // Push the network row with active=1 (forward spinner).
        // Bypass ui_event_starting to avoid a host-dependent monotonic_ms()
        // reading in the demo.
        g_tick = 0
        tape_push(2100, paint("warn", ui_spinner_frame(false)), "network", "", 1)
        // Now bump tick so the live re-render shows frame index 2.
        g_tick = 2
        print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
              str.concat(zyginit_esc_str(), "[H")))
        print(render_boot_screen(2100))
        return 0
    end if
    if scenario == "final_card_ok"
        g_mode = detect_rich_mode()
        ui_boot_start(17, 8, "multi-user")
        let slow = new [string](3)
        slow[0] = "dlmgmtd 1.2s"
        slow[1] = "filesystem 0.55s"
        slow[2] = "sshd 0.37s"
        let stats = BootStats{
            elapsed_ms: 8300,
            online: 17,
            failed: 0,
            skipped: 0,
            slowest: slow,
            slowest_count: 3
        }
        ui_boot_complete(stats)
        return 0
    end if
    if scenario == "final_card_failed"
        g_mode = detect_rich_mode()
        ui_boot_start(17, 8, "multi-user")
        g_failed_first = "network"
        g_failed_first_exit = 1
        let slow = new [string](3)
        slow[0] = "network 5.02s"
        slow[1] = "filesystem 0.55s"
        slow[2] = "sshd 0.37s"
        let stats = BootStats{
            elapsed_ms: 8300,
            online: 16,
            failed: 1,
            skipped: 0,
            slowest: slow,
            slowest_count: 3
        }
        ui_boot_complete(stats)
        return 0
    end if
    if scenario == "shutdown_mirror"
        g_mode = detect_rich_mode()
        ui_boot_start(17, 8, "multi-user")
        ui_shutdown_start("reboot")
        g_boot_start_ms = 0
        tape_push(40,  paint("mute", glyph_pending()), "sshd", "", 0)
        tape_push(160, paint("mute", glyph_pending()), "console-login", "", 0)
        tape_push(310, paint("mute", glyph_pending()), "cron", "", 0)
        // active=2: reverse spinner (stopping)
        g_tick = 0
        tape_push(480, paint("warn", ui_spinner_frame(true)), "syslogd", "", 2)
        g_tick = 3
        g_done = 4
        g_cur_tier = 6
        print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
              str.concat(zyginit_esc_str(), "[H")))
        print(render_boot_screen(480))
        return 0
    end if
    if scenario == "shutdown_final"
        g_mode = detect_rich_mode()
        ui_boot_start(17, 8, "multi-user")
        ui_shutdown_start("reboot")
        g_num_svc = 17
        g_done = 17
        ui_shutdown_complete("reboot", 2100)
        return 0
    end if
    if scenario == "task_ok"
        g_mode = detect_rich_mode()
        ui_boot_start(5, 2, "multi-user")
        g_boot_start_ms = 0
        tape_push(40,  paint("ok", glyph_ok()), "root-fs",  "", 0)
        tape_push(160, paint("ok", glyph_ok()), "task-svc", "", 0)
        g_done = 2
        let slow_tok = new [string](3)
        let stats_tok = BootStats{
            elapsed_ms: 200,
            online: 5,
            failed: 0,
            skipped: 0,
            slowest: slow_tok,
            slowest_count: 0
        }
        ui_boot_complete(stats_tok)
        return 0
    end if

    if scenario == "task_failed"
        g_mode = detect_rich_mode()
        ui_boot_start(5, 2, "multi-user")
        g_boot_start_ms = 0
        tape_push(40,  paint("ok",   glyph_ok()),   "root-fs",  "", 0)
        tape_push(160, paint("fail", glyph_fail()), "task-svc", "exit=1", 0)
        g_done = 2
        g_failed_count = 1
        g_failed_first = "task-svc"
        g_failed_first_exit = 1
        let slow_tf = new [string](3)
        let stats_tf = BootStats{
            elapsed_ms: 200,
            online: 4,
            failed: 1,
            skipped: 0,
            slowest: slow_tf,
            slowest_count: 0
        }
        ui_boot_complete(stats_tf)
        return 0
    end if

    if scenario == "boot_with_skipped"
        g_mode = detect_rich_mode()
        ui_boot_start(5, 2, "multi-user")
        g_boot_start_ms = 0
        tape_push(40,  paint("ok",   glyph_ok()),      "root-fs", "", 0)
        tape_push(160, paint("mute", glyph_pending()), "acpihpd", "skipped: missing /dev/acpihp", 0)
        tape_push(310, paint("ok",   glyph_ok()),      "cron",    "", 0)
        g_done = 2
        g_skipped = 1
        print(str.concat(str.concat(zyginit_esc_str(), "[2J"),
              str.concat(zyginit_esc_str(), "[H")))
        print(render_boot_screen(400))
        return 0
    end if

    if scenario == "final_card_with_skipped"
        g_mode = detect_rich_mode()
        ui_boot_start(23, 9, "multi-user")
        let slow_fcs = new [string](3)
        let stats_fcs = BootStats{
            elapsed_ms: 8300,
            online: 19,
            failed: 0,
            skipped: 4,
            slowest: slow_fcs,
            slowest_count: 0
        }
        ui_boot_complete(stats_fcs)
        return 0
    end if

    if scenario == "status_skipped"
        // status_skipped requires zygctl status table rendering with a
        // SKIPPED row. The existing --ui-demo infrastructure doesn't yet
        // build a ServiceTable mock that ui_render.ui_render_status can
        // render. Deferred — emit a placeholder note so the test exists
        // and tracks the gap.
        g_mode = detect_rich_mode()
        println("status_skipped: deferred — zygctl status snapshot via --ui-demo not yet supported")
        return 0
    end if

    println("ui.reef: unknown demo scenario: " + scenario)
    return 1
end ui_demo

fn int_to_str(n: int): string
    if n == 0
        return "0"
    end if

    mut value = n
    if n < 0
        value = 0 - n
    end if

    mut result = ""
    while value > 0
        let digit = value % 10
        result = str.concat(str.substring("0123456789", digit, 1), result)
        value = value / 10
    end while

    if n < 0
        result = str.concat("-", result)
    end if

    return result
end int_to_str

// ============================================================================
// Status/list rendering (used by socket command handlers)
// ============================================================================

fn pad_right(s: string, n: int): string
    let extra = n - str.length(s)
    if extra <= 0
        return s
    end if
    mut out = s
    mut i = 0
    while i < extra
        out = str.concat(out, " ")
        i = i + 1
    end while
    return out
end pad_right

end module