#!/usr/bin/env python3
"""候选决策通道 —— 会写库（accept / discard）。

与只读看板（:8765）分离：看板合同禁止写；人审决策必须在本通道完成。
与经验确认通道（:8766）并列：本通道只做候选采纳/丢弃。
跑法：.venv/bin/python dashboard/decision_channel.py
默认 http://127.0.0.1:8767
"""

from __future__ import annotations

import html
import json
import sys
import traceback
import uuid
from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
from pathlib import Path
from urllib.parse import parse_qs, urlparse

HOST, PORT = "127.0.0.1", 8767
READONLY_BASE = "http://127.0.0.1:8765"

ROOT = Path(__file__).resolve().parents[1]
SKILLS = ROOT / ".agent" / "skills"
for sub in (
    "decide-candidate/scripts",
    "record-run-evidence/scripts",
):
    p = str(SKILLS / sub)
    if p not in sys.path:
        sys.path.insert(0, p)

from muse_db import connect  # noqa: E402
from write_canonical import ConflictError, accept, discard  # noqa: E402


def esc(value) -> str:
    return html.escape("" if value is None else str(value))


def _page(title: str, body: str) -> str:
    return f"""<!doctype html><html lang="zh"><head><meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<title>{esc(title)} · 候选决策通道</title>
<style>
body{{font-family:ui-sans-serif,system-ui,sans-serif;max-width:900px;margin:24px auto;padding:0 16px;line-height:1.5}}
.banner{{background:#fde8e8;border:1px solid #c44;padding:10px 14px;border-radius:8px;margin-bottom:16px}}
.card{{border:1px solid #ddd;border-radius:8px;padding:14px 16px;margin:14px 0}}
label{{display:block;margin:8px 0 4px}}
input,textarea{{width:100%;max-width:520px;padding:6px 8px}}
button{{margin-top:10px;margin-right:8px;padding:8px 14px}}
button.accept{{background:#0a6b0a;color:#fff;border:0}}
button.discard{{background:#8b0000;color:#fff;border:0}}
pre{{white-space:pre-wrap;background:#f6f6f6;padding:10px;border-radius:6px;font-size:13px;max-height:420px;overflow:auto}}
.err{{color:#a40000}}
.ok{{color:#0a6b0a}}
a{{color:#0645ad}}
.meta{{color:#555;font-size:14px}}
</style></head><body>
<div class="banner"><b>决策通道会写库</b> · 只读浏览请用
<a href="{READONLY_BASE}/">看板 :8765</a> · 本页仅做候选采纳/丢弃
（经验升格仍走 <a href="http://127.0.0.1:8766/">:8766</a>）</div>
{body}
</body></html>"""


def _list_actionable_candidates(limit: int = 40) -> list[dict]:
    with connect(readonly=True) as conn:
        rows = conn.execute(
            """SELECT id, work_id, target_chapter, candidate_version, state,
                      semantic_status, run_id, create_time,
                      left(candidate_body, 160)
               FROM example_candidate
               WHERE deleted=false AND state IN ('passed','rejected','draft','checking')
               ORDER BY id DESC
               LIMIT %s""",
            (limit,),
        ).fetchall()
    return [
        {
            "id": r[0],
            "work_id": r[1],
            "chapter": r[2],
            "version": r[3],
            "state": r[4],
            "semantic": r[5],
            "run_id": r[6],
            "create_time": r[7],
            "preview": r[8] or "",
        }
        for r in rows
    ]


def _load_candidate(candidate_id: int) -> dict | None:
    with connect(readonly=True) as conn:
        row = conn.execute(
            """SELECT id, work_id, target_chapter, run_id, attempt, run_type,
                      candidate_version, candidate_sha256, candidate_body, state,
                      semantic_status, create_time
               FROM example_candidate
               WHERE id=%s AND deleted=false""",
            (candidate_id,),
        ).fetchone()
    if not row:
        return None
    return {
        "id": row[0],
        "work_id": row[1],
        "chapter": row[2],
        "run_id": row[3],
        "attempt": row[4],
        "run_type": row[5],
        "version": row[6],
        "sha256": row[7],
        "body": row[8] or "",
        "state": row[9],
        "semantic": row[10],
        "create_time": row[11],
    }


def view_home(*, flash: str | None = None, error: str | None = None) -> str:
    rows = _list_actionable_candidates()
    flash_html = f"<p class='ok'>{esc(flash)}</p>" if flash else ""
    err_html = f"<p class='err'>{esc(error)}</p>" if error else ""
    if not rows:
        return _page(
            "候选决策",
            flash_html + err_html + "<h1>暂无待决策候选</h1>"
            "<p>库内没有 passed/rejected/draft/checking 态候选。</p>",
        )
    items = []
    for r in rows:
        items.append(
            f"<li><a href='/candidates/{r['id']}'>#{r['id']}</a> "
            f"作品{r['work_id']} 第{r['chapter']}章 v{esc(r['version'])} "
            f"[{esc(r['state'])}/{esc(r['semantic'])}] "
            f"<span class='meta'>{esc(r['create_time'])}</span></li>"
        )
    return _page(
        "候选决策",
        flash_html
        + err_html
        + "<h1>待决策候选</h1>"
        "<p>点进详情后在本页提交采纳或丢弃。采纳要求 state=passed 且 semantic=passed。</p>"
        f"<ul>{''.join(items)}</ul>",
    )


def view_candidate(
    candidate_id: int, *, flash: str | None = None, error: str | None = None
) -> str:
    cand = _load_candidate(candidate_id)
    if not cand:
        return _page("未找到", f"<h1>候选 #{candidate_id} 不存在</h1>")
    flash_html = f"<p class='ok'>{esc(flash)}</p>" if flash else ""
    err_html = f"<p class='err'>{esc(error)}</p>" if error else ""
    ro = (
        f"<p><a href='{READONLY_BASE}/candidates/{candidate_id}'>只读看板打开</a>"
        + (
            f" · <a href='{READONLY_BASE}/runs/{esc(cand['run_id'])}'>运行</a>"
            if cand["run_id"]
            else ""
        )
        + f" · <a href='{READONLY_BASE}/works/{cand['work_id']}'>作品</a></p>"
    )
    meta = (
        f"<p class='meta'>作品 {cand['work_id']} · 第 {cand['chapter']} 章 · "
        f"v{esc(cand['version'])} · attempt={cand['attempt']} · "
        f"run_type={esc(cand['run_type'])} · state={esc(cand['state'])} · "
        f"semantic={esc(cand['semantic'])}</p>"
        f"<p class='meta'>sha={esc(cand['sha256'])}</p>"
    )
    body_preview = esc(cand["body"][:6000])
    if len(cand["body"]) > 6000:
        body_preview += "\n…（截断，完整正文见只读看板）"
    can_accept = cand["state"] == "passed" and cand["semantic"] == "passed"
    can_discard = cand["state"] not in ("accepted", "discarded", "archived")
    forms = ""
    if can_accept or can_discard:
        forms = "<div class='card'><h2>人审决策</h2>"
        if can_accept:
            forms += f"""
            <form method="post" action="/candidates/{candidate_id}/accept"
                  onsubmit="return confirm('确认采纳为正式正文？此操作写库不可静默撤销。');">
              <label>署名（decided_by）</label>
              <input name="decided_by" required placeholder="例如：qingse">
              <label>理据（可选）</label>
              <textarea name="rationale" rows="3"></textarea>
              <button class="accept" type="submit">采纳 → 正式正文</button>
            </form>"""
        else:
            forms += (
                "<p class='err'>当前不可采纳："
                "需要 state=passed 且 semantic_status=passed。</p>"
            )
        if can_discard:
            forms += f"""
            <form method="post" action="/candidates/{candidate_id}/discard"
                  onsubmit="return confirm('确认丢弃该候选？正式正文不变。');">
              <label>署名</label><input name="decided_by" required>
              <label>理据</label><textarea name="rationale" rows="3" required></textarea>
              <button class="discard" type="submit">丢弃</button>
            </form>"""
        forms += "</div>"
    else:
        forms = "<div class='card'><p>该候选已终态，不可再决策。</p></div>"
    return _page(
        f"候选 #{candidate_id}",
        flash_html
        + err_html
        + f"<h1>候选 #{candidate_id}</h1>{ro}{meta}"
        + f"<div class='card'><h2>正文预览</h2><pre>{body_preview}</pre></div>"
        + forms
        + "<p><a href='/'>← 返回列表</a></p>",
    )


class Handler(BaseHTTPRequestHandler):
    def log_message(self, fmt: str, *args) -> None:
        sys.stderr.write("%s - %s\n" % (self.address_string(), fmt % args))

    def _send(self, code: int, body: str, *, content_type: str = "text/html; charset=utf-8") -> None:
        data = body.encode("utf-8")
        self.send_response(code)
        self.send_header("Content-Type", content_type)
        self.send_header("Content-Length", str(len(data)))
        self.end_headers()
        self.wfile.write(data)

    def _read_form(self) -> dict[str, str]:
        length = int(self.headers.get("Content-Length") or 0)
        raw = self.rfile.read(length) if length else b""
        parsed = parse_qs(raw.decode("utf-8"), keep_blank_values=True)
        return {k: (v[0] if v else "") for k, v in parsed.items()}

    def do_GET(self) -> None:
        path = urlparse(self.path).path
        if path in ("/", "/candidates"):
            self._send(200, view_home())
            return
        if path.startswith("/candidates/"):
            parts = path.strip("/").split("/")
            if len(parts) == 2 and parts[1].isdigit():
                self._send(200, view_candidate(int(parts[1])))
                return
        self._send(404, _page("404", "<h1>未找到</h1>"))

    def do_POST(self) -> None:
        path = urlparse(self.path).path
        form = self._read_form()
        parts = path.strip("/").split("/")
        try:
            if len(parts) == 3 and parts[0] == "candidates" and parts[1].isdigit():
                cid = int(parts[1])
                action = parts[2]
                decided_by = (form.get("decided_by") or "").strip() or "1"
                rationale = (form.get("rationale") or "").strip() or None
                command_id = f"decision-channel-{action}-{cid}-{uuid.uuid4().hex[:12]}"
                if action == "accept":
                    result = accept(
                        cid,
                        decided_by=decided_by,
                        rationale=rationale,
                        command_id=command_id,
                    )
                    msg = f"已采纳：{json.dumps(result, ensure_ascii=False, default=str)}"
                    self._send(200, view_candidate(cid, flash=msg))
                    return
                if action == "discard":
                    if not rationale:
                        self._send(
                            400,
                            view_candidate(cid, error="丢弃必须填写理据"),
                        )
                        return
                    result = discard(
                        cid,
                        decided_by=decided_by,
                        rationale=rationale,
                        command_id=command_id,
                    )
                    msg = f"已丢弃：{json.dumps(result, ensure_ascii=False, default=str)}"
                    self._send(200, view_candidate(cid, flash=msg))
                    return
            self._send(404, _page("404", "<h1>未知写路径</h1>"))
        except ConflictError as exc:
            cid = int(parts[1]) if len(parts) > 1 and parts[1].isdigit() else 0
            page = view_candidate(cid, error=str(exc)) if cid else view_home(error=str(exc))
            self._send(409, page)
        except Exception as exc:
            tb = traceback.format_exc()
            self._send(
                500,
                _page("错误", f"<h1>写库失败</h1><pre class='err'>{esc(tb)}</pre>"),
            )


def main() -> None:
    server = ThreadingHTTPServer((HOST, PORT), Handler)
    print(f"候选决策通道（可写） http://{HOST}:{PORT}/", flush=True)
    print(f"只读看板仍为 {READONLY_BASE}/ ；经验确认 :8766", flush=True)
    try:
        server.serve_forever()
    except KeyboardInterrupt:
        print("\n已停止", flush=True)


if __name__ == "__main__":
    main()