"""CLI-shaped web UI: transcript buffer, HTML rendering, layout helpers."""
from __future__ import annotations

import html
from dataclasses import dataclass, field

from .gradio_shell import UiSettings
from .rust_session import list_commands
from .themes import theme_at, theme_names

_BUILTIN_SLASH = [
    "/help", "/mode", "/think", "/mcp", "/rules", "/skills", "/skill", "/bg",
    "/init", "/new", "/sessions", "/rename", "/fork", "/delete", "/timeline",
    "/stats", "/export", "/search", "/config", "/commit", "/agents", "/models",
    "/themes", "/files", "/clear", "/quit",
]

_KIND_STYLE = {
    "user": ("›", "#e2e8f0", "#1e293b"),
    "assistant": ("◆", "#c4b5fd", "#1e1b4b"),
    "tool": ("⚙", "#a78bfa", "#0f172a"),
    "result": ("·", "#94a3b8", "#0f172a"),
    "info": ("·", "#94a3b8", "#0f172a"),
    "error": ("✕", "#f87171", "#450a0a"),
    "final": ("✓", "#34d399", "#052e16"),
}


@dataclass
class TranscriptLine:
    kind: str
    text: str


@dataclass
class Transcript:
    lines: list[TranscriptLine] = field(default_factory=list)
    partial: str = ""

    def clear(self) -> None:
        self.lines.clear()
        self.partial = ""

    def append(self, kind: str, text: str) -> None:
        text = (text or "").strip()
        if not text:
            return
        self.lines.append(TranscriptLine(kind=kind, text=text))

    def append_user(self, text: str) -> None:
        self.append("user", text)

    def append_assistant(self, text: str) -> None:
        self.append("assistant", text)

    def append_info(self, text: str) -> None:
        self.append("info", text)

    def append_error(self, text: str) -> None:
        self.append("error", text)

    def append_tool_call(self, name: str, args: str) -> None:
        self.append("tool", f"{name} {args[:200]}")

    def append_tool_result(self, name: str, text: str) -> None:
        clipped = text[:400] + ("…" if len(text) > 400 else "")
        self.append("result", f"{name}: {clipped}")

    def set_partial(self, text: str) -> None:
        self.partial = text

    def from_stored_chat(self, stored: list[dict[str, str]]) -> None:
        self.clear()
        for m in stored:
            role = m.get("role", "assistant")
            kind = "user" if role == "user" else "assistant"
            self.append(kind, m.get("text", ""))

    def append_final(self, text: str) -> None:
        self.append("final", text)

    def plain_texts(self) -> list[str]:
        return [ln.text for ln in self.lines]

    def search(self, query: str, limit: int = 20) -> list[str]:
        if not query.strip():
            return []
        q = query.lower()
        hits: list[str] = []
        for ln in self.lines:
            if q in ln.text.lower():
                hits.append(f"[{ln.kind}] {ln.text[:120]}")
            if len(hits) >= limit:
                break
        return hits

    def render_html(self, *, running: bool = False) -> str:
        if not self.lines and not self.partial and not running:
            return (
                '<div class="sc-transcript-wrap">'
                '<div class="sc-transcript-empty">'
                "smolcode — describe a coding task, or type <code>/help</code>"
                "</div></div>"
            )
        parts: list[str] = ['<div class="sc-transcript-inner">']
        for ln in self.lines:
            parts.append(_line_html(ln.kind, ln.text))
        if self.partial:
            parts.append(_line_html("assistant", self.partial + "▏"))
        if running and not self.partial:
            parts.append('<div class="sc-tline sc-tline-info">· thinking…</div>')
        parts.append("</div>")
        return f'<div class="sc-transcript-wrap">\n' + "\n".join(parts) + "\n</div>"


def _line_html(kind: str, text: str) -> str:
    glyph, color, _bg = _KIND_STYLE.get(kind, _KIND_STYLE["info"])
    body = html.escape(text).replace("\n", "<br>")
    return (
        f'<div class="sc-tline sc-tline-{kind}">'
        f'<span class="sc-tglyph" style="color:{color}">{glyph}</span> '
        f'<span class="sc-ttext">{body}</span></div>'
    )


def slash_commands(workspace: str) -> list[str]:
    custom = [f"/{n}" for n in list_commands(workspace)]
    return _BUILTIN_SLASH + custom


def filter_slash_commands(prefix: str, workspace: str) -> list[str]:
    p = prefix if prefix.startswith("/") else f"/{prefix}"
    return [c for c in slash_commands(workspace) if c.startswith(p)]


def header_bar_html(
    *,
    git_branch: str = "",
    git_dirty: bool = False,
    model: str = "",
    host: str = "",
    theme: str = "default",
) -> str:
    git_part = ""
    if git_branch:
        dirty = " ●" if git_dirty else ""
        git_part = f'<span class="sc-hgit">⎇ {html.escape(git_branch)}{dirty}</span>'
    model_part = html.escape(model) if model else "—"
    host_part = html.escape(host) if host else ""
    return (
        '<div class="sc-header-bar">'
        f'<span class="sc-hbrand">◆ smol<span class="hf-accent">code</span></span>'
        f"{git_part}"
        f'<span class="sc-hmodel">{model_part}</span>'
        f'<span class="sc-hhost">@ {host_part}</span>'
        f'<span class="sc-htheme">{html.escape(theme)}</span>'
        "</div>"
    )


def status_bar_html(
    settings: UiSettings,
    *,
    session_title: str = "new session",
    model: str = "",
    running: bool = False,
) -> str:
    mode = settings.mode.upper()
    if settings.mode == "auto":
        mode = "AUTO"
    elif settings.mode == "plan":
        mode = "PLAN"
    else:
        mode = "EDIT"
    think = ""
    if settings.think and settings.think != "off":
        think = f'<span class="sc-chip sc-chip-think">think:{settings.think}</span>'
    run = '<span class="sc-chip sc-chip-run">running</span>' if running else ""
    ws = html.escape(settings.workspace[:48])
    sess = html.escape(session_title[:32])
    ag = html.escape(settings.agent)
    mdl = html.escape(model or settings.model or "—")
    return (
        '<div class="sc-status-bar">'
        f'<span class="sc-chip sc-chip-brand">smolcode</span>'
        f'<span class="sc-chip">{sess}</span>'
        f'<span class="sc-chip sc-chip-dim">{ws}</span>'
        f'<button type="button" class="sc-chip sc-chip-clickable" data-picker="agents">{ag}</button>'
        f'<button type="button" class="sc-chip sc-chip-clickable sc-chip-mode" data-action="cycle-mode">{mode}</button>'
        f"{think}{run}"
        f'<button type="button" class="sc-chip sc-chip-clickable sc-chip-model" data-picker="models">{mdl}</button>'
        f'<button type="button" class="sc-chip sc-chip-clickable sc-chip-dim" data-picker="themes">theme</button>'
        "</div>"
    )


def parse_git_header(git_text: str) -> tuple[str, bool]:
    branch = ""
    dirty = False
    for line in git_text.splitlines():
        if line.startswith("##"):
            branch = line[2:].strip().split("...")[0]
        if line.strip() and not line.startswith("#"):
            dirty = True
    return branch, dirty


def host_from_url(base_url: str) -> str:
    u = base_url.strip()
    for prefix in ("https://", "http://"):
        if u.startswith(prefix):
            u = u[len(prefix):]
    return u.split("/")[0] if u else ""


def cycle_mode(current: str) -> str:
    order = ["normal", "auto", "plan"]
    try:
        i = order.index(current)
    except ValueError:
        return "normal"
    return order[(i + 1) % len(order)]


def cycle_think(current: str) -> str:
    order = ["off", "low", "high", "xtra"]
    try:
        i = order.index(current)
    except ValueError:
        return "off"
    return order[(i + 1) % len(order)]


def cycle_agent(current: str) -> str:
    order = ["build", "plan"]
    try:
        i = order.index(current)
    except ValueError:
        return "build"
    return order[(i + 1) % len(order)]


def cycle_model(models: list[str], current: str) -> str:
    if not models:
        return current
    try:
        i = models.index(current)
    except ValueError:
        return models[0]
    return models[(i + 1) % len(models)]


def ingest_agent_event(transcript: Transcript, ev: dict) -> None:
    kind = ev.get("kind")
    if kind == "token":
        transcript.set_partial(transcript.partial + ev.get("text", ""))
    elif kind == "assistant":
        transcript.set_partial(ev.get("text", ""))
    elif kind == "tool_call":
        transcript.set_partial("")
        transcript.append_tool_call(ev.get("name", ""), ev.get("args", ""))
    elif kind == "tool_result":
        transcript.append_tool_result(ev.get("name", ""), ev.get("text", ""))
    elif kind == "final":
        transcript.set_partial("")
        transcript.append_final(ev.get("text", ""))
    elif kind == "error":
        transcript.set_partial("")
        transcript.append_error(ev.get("text", ""))


def help_overlay_html() -> str:
    lines = [
        "Enter — run task",
        "Shift+Enter — newline",
        "/ — slash commands (Tab complete)",
        "@ — attach file",
        "! cmd — shell (no LLM)",
        "Ctrl+L — clear transcript",
        "Ctrl+X — leader key menu",
        "Tab — cycle agent",
        "Shift+Tab — cycle mode",
        "F2 — cycle model",
        "Esc — interrupt / close overlay",
    ]
    body = "<br>".join(html.escape(ln) for ln in lines)
    return f'<div class="sc-overlay-body"><b>smolcode keys</b><br><br>{body}</div>'


def whichkey_overlay_html() -> str:
    lines = [
        "m models", "a agents", "t themes", "l sessions",
        "n new session", "b sidebar", "s stats/files", "f focus files",
        "h help", "o mode", "e think", "q quit",
    ]
    body = "<br>".join(html.escape(ln) for ln in lines)
    return f'<div class="sc-overlay-body"><b>ctrl+x leader</b><br><br>{body}</div>'


def render_picker_html(
    kind: str,
    items: list[str],
    selected: int,
    *,
    title: str | None = None,
) -> str:
    """TUI-style bordered picker list with scroll window."""
    label = title or kind
    if not items:
        return (
            f'<div class="sc-picker" data-kind="{html.escape(kind)}">'
            f'<div class="sc-picker-title">{html.escape(label)}</div>'
            '<div class="sc-picker-empty">(empty)</div></div>'
        )
    win = 12
    sel = min(max(0, selected), len(items) - 1)
    start = max(0, sel - win // 2)
    end = min(len(items), start + win)
    start = max(0, end - win)
    rows: list[str] = []
    for i in range(start, end):
        item = items[i]
        marker = "❯" if i == sel else " "
        cls = "sc-picker-item sc-picker-sel" if i == sel else "sc-picker-item"
        rows.append(
            f'<button type="button" class="{cls}" data-idx="{i}" '
            f'onclick="window.__smolcodePick && window.__smolcodePick({i})">'
            f'<span class="sc-picker-mark">{marker}</span>'
            f"<span>{html.escape(item)}</span></button>"
        )
    body = "\n".join(rows)
    return (
        f'<div class="sc-picker" data-kind="{html.escape(kind)}">'
        f'<div class="sc-picker-title">{html.escape(label)}</div>'
        f'<div class="sc-picker-list">{body}</div>'
        f'<div class="sc-picker-hint">↑↓ navigate · Enter select · Esc close</div>'
        f"</div>"
    )


def shell_theme_html(theme_idx: int) -> str:
    """Inject data-theme on the TUI shell wrapper."""
    name = theme_at(theme_idx).name
    safe = html.escape(name, quote=True)
    return (
        f'<script>(function(){{var el=document.querySelector(".sc-tui-shell");'
        f'if(el)el.setAttribute("data-theme","{safe}");}})();</script>'
    )


def agent_choices() -> list[str]:
    return ["build", "plan"]


def theme_picker_items() -> list[str]:
    return theme_names()


def _sorted_file_paths(files: dict[str, str] | list[str]) -> list[str]:
    if isinstance(files, dict):
        return sorted(files.keys())
    return sorted(files)


def _paths_for_ui(files: dict[str, str] | list[str] | None) -> list[str]:
    return _sorted_file_paths(files or [])


def _files_sidebar_body(paths: list[str], *, selected: int = 0, max_rows: int = 48) -> str:
    """Flat file list grouped by directory, matching the CLI TUI sidebar."""
    if not paths:
        return '<div class="sc-sb-empty">no files</div>'

    rows: list[str] = []
    sel_row: int | None = None
    last_dir = ""
    sel = min(selected, max(0, len(paths) - 1))

    for i, path in enumerate(paths):
        if "/" in path:
            j = path.rfind("/")
            dir_part, file_part = path[:j], path[j + 1 :]
        else:
            dir_part, file_part = "", path
        if dir_part != last_dir:
            last_dir = dir_part
            label = "." if not dir_part else f"{dir_part}/"
            rows.append(f'<div class="sc-sb-dir">▾ {html.escape(label)}</div>')
        is_sel = i == sel
        if is_sel:
            sel_row = len(rows)
        prefix = "❯" if is_sel else ""
        cls = "sc-sb-file sc-sb-sel" if is_sel else "sc-sb-file"
        rows.append(
            f'<div class="{cls}">'
            f'<span class="sc-sb-mark">{prefix}</span>'
            f'<span class="sc-sb-glyph"> </span>'
            f'<span class="sc-sb-name">{html.escape(file_part)}</span>'
            f"</div>"
        )

    total = len(rows)
    start = 0
    if total > max_rows:
        anchor = sel_row if sel_row is not None else 0
        start = min(max(0, anchor - max_rows + 1), total - max_rows)

    visible = rows[start : start + max_rows]
    if total > max_rows and start + max_rows < total:
        more = total - (start + max_rows) + 1
        visible.append(f'<div class="sc-sb-more">… +{more} more</div>')

    return "\n".join(visible)


def _stats_sidebar_body(
    *,
    session_id: str,
    file_count: int,
    agent: str,
    extra_lines: list[str] | None = None,
) -> str:
    parts = [
        f'<div class="sc-sb-stat sc-sb-dim">{html.escape(session_id[:26])}</div>',
        '<div class="sc-sb-stat"></div>',
    ]
    for line in extra_lines or []:
        parts.append(f'<div class="sc-sb-stat">{html.escape(line)}</div>')
    parts.append(f'<div class="sc-sb-stat">files: {file_count}</div>')
    parts.append(f'<div class="sc-sb-stat">agent: {html.escape(agent)}</div>')
    return "\n".join(parts)


def render_sidebar_html(
    *,
    view: str = "files",
    files: dict[str, str] | list[str] | None = None,
    selected: int = 0,
    focused: bool = False,
    session_id: str = "(none)",
    agent: str = "build",
    stats_lines: list[str] | None = None,
    file_total: int | None = None,
) -> str:
    """CLI TUI-shaped sidebar panel (flat file list or stats)."""
    paths = _paths_for_ui(files)
    total = file_total if file_total is not None else len(paths)
    title = "stats" if view == "stats" else ("files ▸" if focused else "files")
    panel_cls = "sc-sidebar-panel"
    if focused:
        panel_cls += " sc-sidebar-focused"

    if view == "stats":
        body = _stats_sidebar_body(
            session_id=session_id,
            file_count=total,
            agent=agent,
            extra_lines=stats_lines,
        )
    else:
        body = _files_sidebar_body(paths, selected=selected)
        if total > len(paths):
            body += f'\n<div class="sc-sb-more">… {total - len(paths)} more files</div>'

    return (
        f'<div class="{panel_cls}">'
        f'<div class="sc-sidebar-title">{html.escape(title)}</div>'
        f'<div class="sc-sidebar-body">{body}</div>'
        f"</div>"
    )