local here = (arg and arg[0] or "_selfcheck.lua"):match("^(.*)/") or "."
package.path = here .. "/?.lua;" .. here .. "/?/init.lua;" .. package.path

local config = require("rsvp.config")
local module = require("rsvp.player")
local Player = module.Player

local defaults = assert(config.read())
assert(defaults.wpm == 250 and defaults.wpm_step == 25 and defaults.min_wpm == 50)
assert(config.read({ wpm = 25 }).wpm == 50, "configured speed respects lower bound")
assert(config.read({ typo = 1 }) == nil, "unknown settings are rejected")
for _, bad in ipairs({ 0, -1, 0 / 0, math.huge, "fast" }) do
    local settings, err = config.read({ wpm = bad })
    assert(settings == nil and err:find("rsvp.wpm"), "invalid WPM rejected")
end

local function plain(text)
    return (text or ""):gsub("\27%[[0-9;:]*m", ""):gsub("\27%]8;;.-\27\\", "")
end

local function char_width(char)
    local cp = utf8.codepoint(char)
    if (cp >= 0x0300 and cp <= 0x036f) or cp == 0x200d
        or (cp >= 0xfe00 and cp <= 0xfe0f) then return 0 end
    if cp >= 0x1100 and (cp <= 0x115f or cp == 0x2329 or cp == 0x232a
        or (cp >= 0x2e80 and cp <= 0xa4cf) or (cp >= 0xac00 and cp <= 0xd7a3)
        or (cp >= 0xf900 and cp <= 0xfaff) or (cp >= 0xfe10 and cp <= 0xfe6f)
        or (cp >= 0xff00 and cp <= 0xff60) or (cp >= 0x1f300 and cp <= 0x1faff)) then return 2 end
    return 1
end

local function display_width(text)
    local stripped, width = plain(text), 0
    for _, cp in utf8.codes(stripped) do width = width + char_width(utf8.char(cp)) end
    return width
end

local function truncate_display(text, max_width)
    local output, width, i = {}, 0, 1
    while i <= #text do
        if text:sub(i, i) == "\27" then
            local sequence = text:match("^(\27%[[0-9;:]*m)", i) or text:match("^(\27%]8;;.-\27\\)", i)
            if sequence then output[#output + 1] = sequence; i = i + #sequence
            else output[#output + 1] = text:sub(i, i); i = i + 1 end
        else
            local cp = utf8.codepoint(text, i)
            local char = utf8.char(cp)
            local char_width = char_width(char)
            if width + char_width > max_width then break end
            output[#output + 1] = char
            width, i = width + char_width, i + #char
        end
    end
    output[#output + 1] = "\27]8;;\27\\\27[0m"
    return table.concat(output)
end

local function host(options)
    options = options or {}
    local h = { timers = {}, modes = {}, mounts = {}, highlighted = {}, styles = { welcome = "a", tool_header = "b" } }
    function h.new_timer()
        local timer = { active = false, closing = false, close_count = 0 }
        function timer:start(timeout, repeat_ms, callback)
            assert(repeat_ms == 0, "word timers must be one-shot")
            self.timeout, self.callback, self.active = timeout, callback, true
        end
        function timer:stop() self.active = false end
        function timer:is_active() return self.active end
        function timer:is_closing() return self.closing end
        function timer:close()
            if not self.closing then self.closing, self.active, self.close_count = true, false, self.close_count + 1 end
        end
        h.timers[#h.timers + 1] = timer
        return timer
    end
    function h.input_mode(spec)
        local mode = { spec = spec, closed = false }
        function mode:close()
            if self.closed then return end
            self.closed = true
            self.spec.on_exit("closed")
        end
        function mode:exit(reason, message)
            if self.closed then return end
            self.closed = true
            self.spec.on_exit(reason, message)
        end
        h.modes[#h.modes + 1] = mode
        return mode
    end
    function h.mount(component, placement)
        assert(placement == "above_input")
        local mount = { component = component, invalidations = 0, unmounts = 0 }
        function mount:invalidate() self.invalidations = self.invalidations + 1 end
        function mount:unmount() self.unmounts = self.unmounts + 1 end
        h.mounts[#h.mounts + 1] = mount
        return mount
    end
    h.options = options
    h.player = Player.new {
        settings = options.settings or { wpm = 250, wpm_step = 25, min_wpm = 50 },
        save_wpm = options.save_wpm or function() return true end,
        persistence_error = options.persistence_error,
        highlight = function(body)
            h.highlighted[#h.highlighted + 1] = body
            if options.highlight then return options.highlight(body) end
            return body
        end,
        width = display_width,
        truncate = truncate_display,
        style = function() return h.styles end,
        new_timer = h.new_timer,
        mount = h.mount,
        input_mode = h.input_mode,
    }
    return h
end

local function key(h, chord)
    for _, binding in ipairs(h.modes[#h.modes].spec.keys) do
        if binding.key == chord then binding.run(h.modes[#h.modes]); return end
    end
    error("missing mode key " .. chord)
end

local function fire(timer)
    assert(timer and timer.callback, "expected a scheduled timer")
    timer.active = false
    timer.callback()
end

local function finish_paragraph(player)
    while player.playback do fire(player.timer) end
end

-- A new block, even an empty one, replaces the prior source. Delta updates
-- retain generation/cursor; only newline-terminated segments are streamable.
do
    local h, p = host(), nil
    p = h.player
    p:set_source("older text\n", true, 4)
    local first_generation = p.generation
    assert(p:activate())
    local idle = p:render(20)
    assert(not p.playback and p.timer == nil and idle[1]:sub(11, 11) == "|" and idle[3] == idle[1],
        "activation stays idle with stationary centered focus markers")
    assert(plain(p:render(80)[4]):find("Ready · Ctrl+S to start", 1, true)
        and h.modes[1].spec.keys[1].desc == "start/next", "idle prompt and control description explain playback")
    key(h, "ctrl+s")
    local stale = p.timer
    assert(plain(p.current_word) == "older")

    p:set_source("", false, 0)
    assert(p.generation == first_generation + 1 and p.current_word == nil)
    assert(not p:update_source("stale block", true, 4) and p.source == "", "older block updates are rejected")
    assert(stale.closing, "source replacement closes the old timer")
    stale.callback()
    assert(p.current_word == nil and p.playback == nil, "stale generation cannot paint")
    assert(not p:next(), "empty streaming block has no eligible segment")

    local generation = p.generation
    p:update_source("first", false, 0)
    assert(p.generation == generation and not p:next(), "unterminated segment waits")
    p:update_source("first\nsecond", false, 0)
    assert(p:next() and plain(p.current_word) == "first", "newline makes the first segment eligible")
    local word_timer = p.timer
    key(h, "ctrl+s")
    assert(plain(p.current_word) == "first" and p.timer == word_timer, "Ctrl+S cannot skip during playback")
    p:update_source("first\nsecond\n", true, 0)
    finish_paragraph(p)
    assert(p.cursor == 2, "paragraph read advances only after its final interval")
    assert(p:next() and plain(p.current_word) == "second", "completed block exposes its final segment")
    finish_paragraph(p)
    assert(p.status == "Nothing more to read")
    p:cancel("session_end")
end

-- Paragraph progress skips blank source segments but an interrupted active
-- paragraph remains the next unread segment.
do
    local h = host()
    local p = h.player
    p:set_source("\n\nrestart me\n", true, 2)
    assert(p:activate())
    key(h, "ctrl+s")
    assert(plain(p.current_word) == "restart")
    assert(p.cursor == 3, "cursor retains the original source segment index")
    p:cancel("closed")
    assert(p.cursor == 3, "cancel does not mark the active paragraph read")
    assert(p:activate())
    key(h, "ctrl+s")
    assert(plain(p.current_word) == "restart", "next activation restarts unfinished paragraph")
    p:cancel("closed")
end

-- Matched backtick/tilde fences are omitted line-for-line; mismatched closers
-- do not end a fence, and an unclosed fence suppresses the remainder.
do
    local source = "read\n```lua\nprint(1)\n~~~\nstill code\n```\nafter\n~~~mermaid\ngraph TD\n~~~\nlast"
    local filtered = module.filter_source(source)
    assert(filtered == "read\n\n\n\n\n\nafter\n\n\n\nlast", "matched fences preserve source lines")
    local function newlines(s) local _, n = s:gsub("\n", ""); return n end
    assert(newlines(filtered) == newlines(source), "fence omission retains newline boundaries")
    local unclosed = module.filter_source("spoken\n~~~mermaid\nsecret\nstill secret\n")
    assert(unclosed == "spoken\n\n\n\n", "unclosed fence suppresses to end")

    local h, p = host(), nil
    p = h.player
    p:set_source(source, true, 1)
    assert(p:activate())
    key(h, "ctrl+s")
    assert(plain(p.current_word) == "read")
    assert(h.highlighted[1] == filtered, "highlight receives the complete filtered body")
    finish_paragraph(p)
    assert(p:next() and plain(p.current_word) == "after")
    finish_paragraph(p)
    assert(p:next() and plain(p.current_word) == "last")
    finish_paragraph(p)
    assert(p.status == "Nothing more to read")
    p:cancel("closed")
end

-- ANSI spans survive word splitting and source-line splitting. Theme changes
-- re-highlight the active snapshot without moving its word cursor.
do
    local esc = "\27"
    local h = host {
        highlight = function(body)
            local lines = #body > 0 and (select(2, body:gsub("\n", "")) + 1) or 1
            if lines == 1 then return esc .. "[1mone two" .. esc .. "[0m" end
            return esc .. "[1mone two" .. esc .. "[0m\n" .. esc .. "[1mthree four" .. esc .. "[0m"
        end,
    }
    local p = h.player
    p:set_source("one two\nthree four", true, 1)
    assert(p:activate())
    key(h, "ctrl+s")
    assert(p.current_word:find(esc .. "%[1m"))
    local first_timer = p.timer
    fire(first_timer)
    assert(p.current_word:find("two") and p.current_word:find(esc .. "%[1m"), "style replays at the next word")
    local before_cursor, before_word, before_highlights = p.cursor, p.playback.word_index, #h.highlighted
    h.styles.welcome = "changed"
    p.component:render(40)
    assert(#h.highlighted > before_highlights, "theme change rebuilds Markdown styling")
    assert(p.cursor == before_cursor and p.playback.word_index == before_word, "theme refresh preserves progress")
    fire(p.timer)
    assert(p:next() and p.current_word:find("three") and p.current_word:find(esc .. "%[1m"), "style continues on the next source line")
    p:cancel("closed")
end

-- Pause/resume gets a fresh interval; speed changes affect the next interval,
-- not the currently displayed word. The final interval commits read progress.
do
    local h = host { settings = { wpm = 100, wpm_step = 25, min_wpm = 50 } }
    local p = h.player
    p:set_source("one two", true, 1)
    assert(p:activate())
    assert(p.timer == nil and p.current_word == nil, "activation does not schedule playback")
    key(h, "ctrl+s")
    local first_timer = p.timer
    assert(first_timer.timeout == 600)
    key(h, "ctrl+s")
    assert(p.timer == first_timer and plain(p.current_word) == "one", "Ctrl+S is ignored during playback")

    key(h, "space")
    assert(p.paused and first_timer.closing and plain(p.current_word) == "one")
    key(h, "-")
    assert(p.wpm == 75 and p.paused and p.timer == nil, "speed change stays paused")
    key(h, "space")
    local resumed = p.timer
    assert(resumed.timeout == 800 and plain(p.current_word) == "one", "resume gives the current word a fresh interval")
    key(h, "+")
    assert(p.wpm == 100 and p.timer == resumed, "speed does not restart the current interval")
    assert(p.cursor == 1, "not read before the final word interval")
    fire(resumed)
    assert(plain(p.current_word) == "two" and p.timer.timeout == 600 and p.cursor == 1)
    local final = p.timer
    fire(final)
    assert(p.cursor == 2 and p.status == "Nothing more to read", "final interval marks the paragraph read")
    for _ = 1, 10 do p:adjust(-1) end
    assert(p.wpm == 50, "speed adjustments stop at the configured lower bound")
    p:cancel("closed")
end

-- Markdown failure is visible and never falls back to speaking raw source.
do
    local h = host { highlight = function() error("renderer unavailable") end }
    local p = h.player
    p:set_source("**not raw playback**", true, 1)
    assert(p:activate())
    key(h, "ctrl+s")
    assert(p.playback == nil and p.current_word == nil)
    key(h, "ctrl+s")
    assert(p.playback == nil and p.current_word == nil)
    assert(p.status:find("Markdown rendering failed", 1, true))
    p:cancel("closed")
end

-- Suspension stops playback and requires the same explicit Space resume.
do
    local h = host()
    local p = h.player
    p:set_source("stay visible\n", true, 1)
    assert(p:activate())
    key(h, "ctrl+s")
    local timer, word = p.timer, p.current_word
    p:suspend()
    assert(p.paused and timer.closing and p.current_word == word)
    key(h, "space")
    assert(not p.paused and p.timer ~= timer and p.current_word == word)
    p:cancel("closed")
end

-- Every host exit/cancel path closes stale timers and unmounts exactly once.
for _, exit in ipairs({ "closed", "turn", "session", "error", "teardown", "session_end" }) do
    local h = host()
    local p = h.player
    p:set_source("unfinished paragraph\n", true, 1)
    assert(p:activate())
    key(h, "ctrl+s")
    local stale, mode, mount = p.timer, h.modes[1], h.mounts[1]
    local paints = mount.invalidations
    if exit == "closed" then
        key(h, "escape")
    elseif exit == "session_end" then
        p:cancel(exit)
    else
        mode:exit(exit, exit == "error" and "test error" or nil)
    end
    assert(stale.closing and p.timer == nil and p.mount == nil, exit .. " closes timer and mount")
    stale.callback()
    assert(p.playback == nil and mount.invalidations == paints, exit .. " stale callback is inert")
    assert(mount.unmounts == 1, exit .. " unmounts exactly once")
end

-- Focus buckets count visible non-punctuation characters, not ANSI bytes, and
-- alignment uses display columns including leading punctuation and Unicode width.
do
    local h = host()
    local p = h.player
    p:activate()
    local cases = {
        { "x", 1 }, { "ab", 2 }, { "abcde", 2 }, { "abcdef", 3 },
        { "abcdefghi", 3 }, { "abcdefghij", 4 }, { "abcdefghijklm", 4 },
        { "abcdefghijklmn", 5 }, { "well-known,", 3 },
        { "'books,'", 3 }, { "“books,”", 3 }, { "!!!", 1 },
        { "\27[1mabcdef\27[0m", 3 }, { "e\204\129abcd", 3 },
        { "界界界abc", 3 }, { "「界界界。」", 3 },
    }
    for _, case in ipairs(cases) do
        p.current_word = case[1]
        local rows = p:render(40)
        assert(rows[1]:sub(21, 21) == "|" and rows[3] == rows[1], "focus markers stay centered and stationary")
        local visible = plain(rows[2])
        local lead = #(visible:match("^( *)") or "")
        local word = visible:sub(lead + 1)
        local chars = {}
        for _, cp in utf8.codes(word) do chars[#chars + 1] = utf8.char(cp) end
        local before = 0
        for i = 1, case[2] - 1 do before = before + char_width(chars[i]) end
        assert(lead + before + 1 == 21, "focus column correct for " .. case[1])
        if case[1]:find("\27", 1, true) then assert(rows[2]:find("\27[1m", 1, true), "ANSI styling survives alignment") end
    end

    p.current_word = "\27[1mabcdefghijklmnopqrstuv\27[0m"
    local narrow = p:render(8)
    assert(narrow[1] == "    |" and narrow[3] == narrow[1], "narrow view bounds centered marker")
    for _, row in ipairs(narrow) do assert(display_width(row) <= 8, "rendered row stays within viewport") end
    assert(narrow[2]:find("\27[1m", 1, true), "narrow clipping preserves ANSI styling")

    p.current_word = "界界界界界界"
    narrow = p:render(3)
    assert(narrow[1] == " |" and narrow[3] == narrow[1], "marker clamps to the viewport center")
    for _, row in ipairs(narrow) do assert(display_width(row) <= 3, "wide glyph clipping stays bounded") end
    for _, width in ipairs({ 0, 1, 2, 3, 8, 40 }) do
        for _, row in ipairs(p:render(width)) do
            assert(display_width(row) <= width, "all rows fit even a zero-width viewport")
        end
    end
    p:cancel("closed")
end

-- Speed changes persist only when the value really changes; failures keep the
-- in-memory speed and remain visible without interrupting RSVP.
do
    local writes = {}
    local h = host { settings = { wpm = 100, wpm_step = 25, min_wpm = 50 },
        save_wpm = function(value) writes[#writes + 1] = value; return nil, "disk unavailable" end }
    local p = h.player
    assert(p:adjust(-1) == 75 and writes[1] == 75, "changed speed is persisted")
    assert(p.persistence_error:find("disk unavailable", 1, true), "save failure is retained")
    assert(plain(p:render(80)[5]):find("WPM save failed", 1, true), "save failure is surfaced in the view")
    p:adjust(1)
    assert(p.wpm == 100 and p.persistence_error, "failed save does not roll back speed")
    local count = #writes
    for _ = 1, 10 do p:adjust(-1) end
    assert(p.wpm == 50 and #writes == count + 2, "clamped no-op adjustments are not persisted")
    p.save_wpm = function() return true end
    p:adjust(1)
    assert(p.persistence_error == nil, "successful save clears the previous warning")
end

-- Init reads/writes only through ext.state and opens in idle mode. Invalid saved
-- values use configured WPM; storage errors stay visible but do not block use.
do
    local function launch(saved, read_error, write_error)
        local h, events, persisted = host(), {}, saved
        local command
        local ext = {
            config = { rsvp = { wpm = 100, wpm_step = 25, min_wpm = 50 } },
            state = {
                get = function(key)
                    assert(key == "rsvp.wpm")
                    return persisted, read_error
                end,
                set = function(key, value)
                    assert(key == "rsvp.wpm")
                    if write_error then return nil, write_error end
                    persisted = value
                    return true
                end,
            },
            on = function(name, callback) events[name] = callback end,
            highlight = function(body) return body end,
            style = function() return h.styles end,
            mount = h.mount,
            input_mode = h.input_mode,
            register_command = function(spec) command = spec end,
        }
        package.loaded.panto = { ext = ext, text = { width = display_width, truncate = truncate_display } }
        package.loaded.luv = { new_timer = function() return h.new_timer() end }
        local extension = dofile(here .. "/init.lua")
        extension.activate()
        assert(command and command.name == "rsvp")
        command.handler("")
        return h, events, function() return persisted end
    end

    local h, events, persisted = launch(30)
    local idle = h.mounts[1].component:render(40)
    assert(h.timers[1] == nil and idle[1]:sub(21, 21) == "|" and idle[3] == idle[1],
        "extension activation is visible but schedules no playback")
    assert(plain(idle[4]):find("50 WPM", 1, true), "saved speed clamps to configured minimum")
    events.render_assistant_text({ text = "first paragraph\nsecond", index = 1 })
    key(h, "ctrl+s")
    assert(h.timers[1] and plain(h.mounts[1].component:render(40)[2]):find("first", 1, true),
        "first Ctrl+S starts the first paragraph")
    key(h, "+")
    assert(persisted() == 75, "extension saves WPM through ext.state.set")
    key(h, "escape")

    h = launch(175)
    assert(plain(h.mounts[1].component:render(40)[4]):find("175 WPM", 1, true),
        "finite positive saved WPM overrides configured fallback")
    key(h, "escape")

    for _, invalid in ipairs({ 0, -1, 0 / 0, math.huge, "fast" }) do
        h = launch(invalid)
        local view = h.mounts[1].component:render(40)
        assert(plain(view[4]):find("100 WPM", 1, true), "invalid saved WPM uses configured fallback")
        key(h, "escape")
    end

    h = launch(nil, "read denied")
    local warning = h.mounts[1].component:render(60)
    assert(plain(warning[4]):find("100 WPM", 1, true) and plain(warning[5]):find("read denied", 1, true),
        "read failure falls back and is displayed")
    key(h, "+")
    assert(#h.mounts[1].component:render(60) == 4, "successful save clears the resolved restore warning")
    key(h, "escape")

    h = launch(nil, nil, "write denied")
    key(h, "+")
    assert(plain(h.mounts[1].component:render(60)[5]):find("write denied", 1, true),
        "extension displays ext.state.set failures")
    key(h, "escape")
end

print("panto-rsvp self-check passed")