import asyncio
import json
import queue
import shutil
import sys
import threading
import time
from pathlib import Path

PROJECT_ROOT = Path(__file__).resolve().parent.parent
sys.path.insert(0, str(PROJECT_ROOT))

from fastapi import FastAPI, File, Form, HTTPException, Request, UploadFile
from fastapi.responses import FileResponse, StreamingResponse
from fastapi.staticfiles import StaticFiles

from prompt_loader import load_prompt

FRONTEND_DIR = PROJECT_ROOT / "frontend"
FRONTEND_ASSETS_DIR = FRONTEND_DIR / "assets"
DATA_ROOT = PROJECT_ROOT / "data"
DATA_DIR = DATA_ROOT / "meetings"
RESULTS_MD_DIR = PROJECT_ROOT / "data" / "results" / "md"
RESULTS_JSON_DIR = PROJECT_ROOT / "data" / "results" / "json"
TEMPLATE_DIR = PROJECT_ROOT / "template"
TEMPLATE_GUIDE_DIR = PROJECT_ROOT / "template_guides"
PROMPT_DIR = PROJECT_ROOT / "prompt" / "zh"
EXAMPLES_DIR = PROJECT_ROOT / "examples"
CONFIG_FILE = PROJECT_ROOT / "config.json"
APP_STATE_FILE = DATA_ROOT / "app_state.json"

DATA_DIR.mkdir(parents=True, exist_ok=True)
RESULTS_MD_DIR.mkdir(parents=True, exist_ok=True)
RESULTS_JSON_DIR.mkdir(parents=True, exist_ok=True)
FRONTEND_ASSETS_DIR.mkdir(parents=True, exist_ok=True)
TEMPLATE_GUIDE_DIR.mkdir(parents=True, exist_ok=True)

app = FastAPI(title="Meeting Summary Web")
app.mount("/assets", StaticFiles(directory=str(FRONTEND_ASSETS_DIR)), name="assets")
_template_lock_guard = threading.Lock()
_template_locks: dict[str, threading.Lock] = {}


def _load_config() -> dict:
    if CONFIG_FILE.exists():
        return json.loads(CONFIG_FILE.read_text(encoding="utf-8"))
    return {
        "api_base_url": "http://10.100.53.199:9527/v1",
        "api_key": "unis123",
        "model_name": "Qwen3.6-35B",
    }


def _save_config(cfg: dict):
    CONFIG_FILE.write_text(json.dumps(cfg, ensure_ascii=False, indent=2), encoding="utf-8")


def _load_app_state() -> dict:
    if APP_STATE_FILE.exists():
        return json.loads(APP_STATE_FILE.read_text(encoding="utf-8"))
    return {"active_meeting_id": None}


def _save_app_state(state: dict):
    APP_STATE_FILE.write_text(json.dumps(state, ensure_ascii=False, indent=2), encoding="utf-8")


def _set_active_meeting(meeting_id: str | None):
    state = _load_app_state()
    state["active_meeting_id"] = meeting_id
    _save_app_state(state)


def _get_llm_client(cfg: dict):
    from openai import OpenAI

    return OpenAI(api_key=cfg["api_key"], base_url=cfg["api_base_url"])


def _llm_stream(client, model, system_prompt, user_prompt, max_token=64000):
    response = client.chat.completions.create(
        model=model,
        messages=[
            {"role": "system", "content": system_prompt},
            {"role": "user", "content": user_prompt},
        ],
        temperature=0.7,
        max_tokens=max_token,
        stream=True,
    )
    for chunk in response:
        delta = chunk.choices[0].delta
        if delta.content is None:
            yield "reasoning", delta.reasoning
        else:
            yield "content", delta.content


def _read_meeting_meta(meeting_id: str) -> dict:
    meta_path = DATA_DIR / meeting_id / "meta.json"
    if meta_path.exists():
        return json.loads(meta_path.read_text(encoding="utf-8"))
    return {"name": meeting_id, "created_at": ""}


def _write_meeting_meta(meeting_id: str, meta: dict):
    meta_path = DATA_DIR / meeting_id / "meta.json"
    meta_path.parent.mkdir(parents=True, exist_ok=True)
    meta_path.write_text(json.dumps(meta, ensure_ascii=False, indent=2), encoding="utf-8")


def _resolve_child(base_dir: Path, name: str) -> Path:
    target = (base_dir / name).resolve()
    if target.parent != base_dir.resolve():
        raise HTTPException(400, "Invalid resource path")
    return target


def _guide_path(template_name: str) -> Path:
    return _resolve_child(TEMPLATE_GUIDE_DIR, template_name)


def _get_template_lock(template_name: str) -> threading.Lock:
    with _template_lock_guard:
        if template_name not in _template_locks:
            _template_locks[template_name] = threading.Lock()
        return _template_locks[template_name]


def _collect_llm_content(client, model, system_prompt: str, user_prompt: str, max_token: int = 64000) -> str:
    content = []
    for chunk_type, chunk_content in _llm_stream(client, model, system_prompt, user_prompt, max_token=max_token):
        if chunk_type == "content" and chunk_content:
            content.append(str(chunk_content))
    return "".join(content).strip()


def _parse_template_guide(template_name: str, template_content: str, cfg: dict | None = None) -> str:
    prompt = load_prompt("templatet_parser", "zh")
    config = cfg or _load_config()
    client = _get_llm_client(config)
    system_prompt = prompt["system"]["role"] + prompt["mode_contracts"]["parse_template_requirements"]
    user_prompt = prompt["user_template"]["template_input"].format(
        template_name=template_name,
        template_content=template_content,
    )
    return _collect_llm_content(client, config["model_name"], system_prompt, user_prompt)


def _ensure_template_guide(template_name: str, *, force: bool = False, cfg: dict | None = None) -> str:
    template_path = _resolve_child(TEMPLATE_DIR, template_name)
    if not template_path.exists():
        raise HTTPException(404, f"Template not found: {template_name}")

    lock = _get_template_lock(template_name)
    with lock:
        guide_path = _guide_path(template_name)
        if guide_path.exists() and not force:
            return guide_path.read_text(encoding="utf-8")

        guide_content = _parse_template_guide(
            template_name=template_name,
            template_content=template_path.read_text(encoding="utf-8"),
            cfg=cfg,
        )
        guide_path.write_text(guide_content, encoding="utf-8")
        return guide_content


def _find_transcript_file(meeting_id: str) -> Path | None:
    mdir = DATA_DIR / meeting_id
    for ext in (".txt", ".md"):
        fp = mdir / f"transcript{ext}"
        if fp.exists():
            return fp
    return None


def _meeting_summary(meeting_id: str) -> dict:
    meta = _read_meeting_meta(meeting_id)
    transcript_file = _find_transcript_file(meeting_id)
    result_md = RESULTS_MD_DIR / meeting_id / "meeting_summary.md"
    result_json = RESULTS_JSON_DIR / meeting_id / "sub_topic.json"
    return {
        "id": meeting_id,
        "name": meta.get("name", meeting_id),
        "created_at": meta.get("created_at", ""),
        "original_filename": meta.get("original_filename", ""),
        "transcript_filename": transcript_file.name if transcript_file else "",
        "has_transcript": transcript_file is not None,
        "has_summary": result_md.exists(),
        "has_topics": result_json.exists(),
    }


def _list_meeting_ids() -> list[str]:
    if not DATA_DIR.exists():
        return []
    return sorted([p.name for p in DATA_DIR.iterdir() if p.is_dir()], reverse=True)


def _list_meetings() -> list[dict]:
    return [_meeting_summary(meeting_id) for meeting_id in _list_meeting_ids()]


@app.get("/")
async def index():
    return FileResponse(str(FRONTEND_DIR / "index.html"))


@app.get("/api/settings")
async def get_settings():
    return _load_config()


@app.put("/api/settings")
async def save_settings(cfg: dict):
    required = {"api_base_url", "api_key", "model_name"}
    if not required.issubset(cfg.keys()):
        raise HTTPException(400, f"Missing fields: {required - set(cfg.keys())}")
    _save_config(cfg)
    return {"ok": True}


@app.get("/api/tree")
async def file_tree():
    active_meeting_id = _load_app_state().get("active_meeting_id")
    tree = {"name": "workspace", "type": "folder", "children": []}

    def _build_branch(label, base_dir, prefix, delete_mode):
        branch = {"name": label, "type": "folder", "children": []}
        if base_dir.exists():
            for subdir in sorted(base_dir.iterdir()):
                if not subdir.is_dir():
                    continue
                meta = _read_meeting_meta(subdir.name)
                children = []
                for f in sorted(subdir.iterdir()):
                    if f.is_file() and f.name != "meta.json":
                        children.append(
                            {
                                "name": f.name,
                                "type": "file",
                                "path": f"{prefix}/{subdir.name}/{f.name}",
                            }
                        )
                branch["children"].append(
                    {
                        "name": meta.get("name", subdir.name),
                        "type": "folder",
                        "id": subdir.name,
                        "active": subdir.name == active_meeting_id,
                        "delete_mode": delete_mode,
                        "children": children,
                    }
                )
        tree["children"].append(branch)

    def _build_flat_branch(label, base_dir, prefix, suffixes, delete_mode=None):
        branch = {"name": label, "type": "folder", "children": []}
        if base_dir.exists():
            for f in sorted(base_dir.iterdir()):
                if f.is_file() and f.suffix in suffixes:
                    node = {
                        "name": f.name,
                        "type": "file",
                        "path": f"{prefix}/{f.name}",
                    }
                    if delete_mode:
                        node["delete_mode"] = delete_mode
                    branch["children"].append(node)
        tree["children"].append(branch)

    _build_branch("会议原文", DATA_DIR, "meetings", "meeting")
    _build_branch("会议结果", RESULTS_MD_DIR, "results_md", "results")
    _build_branch("结构化主题", RESULTS_JSON_DIR, "results_json", "results")
    _build_flat_branch("提示词", PROMPT_DIR, "prompts", {".yaml", ".yml"})
    _build_flat_branch("模板", TEMPLATE_DIR, "templates", {".md"}, delete_mode="template")
    _build_flat_branch("模板说明", TEMPLATE_GUIDE_DIR, "template_guides", {".md"})
    return tree


@app.get("/api/meetings")
async def list_meetings():
    active_meeting_id = _load_app_state().get("active_meeting_id")
    return {"active_meeting_id": active_meeting_id, "meetings": _list_meetings()}


@app.get("/api/current-meeting")
async def get_current_meeting():
    active_meeting_id = _load_app_state().get("active_meeting_id")
    if not active_meeting_id:
        return {"active_meeting_id": None, "meeting": None}
    if not (DATA_DIR / active_meeting_id).exists():
        _set_active_meeting(None)
        return {"active_meeting_id": None, "meeting": None}
    return {
        "active_meeting_id": active_meeting_id,
        "meeting": _meeting_summary(active_meeting_id),
    }


@app.put("/api/current-meeting")
async def set_current_meeting(payload: dict):
    meeting_id = payload.get("meeting_id")
    if meeting_id is not None and not (DATA_DIR / meeting_id).exists():
        raise HTTPException(404, "Meeting not found")
    _set_active_meeting(meeting_id)
    return {
        "ok": True,
        "active_meeting_id": meeting_id,
        "meeting": _meeting_summary(meeting_id) if meeting_id else None,
    }


@app.post("/api/meetings/import")
async def import_meeting(name: str = Form(...), file: UploadFile = File(...)):
    if not file.filename:
        raise HTTPException(400, "No file selected")
    ext = Path(file.filename).suffix.lower()
    if ext not in (".txt", ".md"):
        raise HTTPException(400, "Only .txt and .md files are supported")

    meeting_id = str(int(time.time() * 1000))
    meeting_dir = DATA_DIR / meeting_id
    meeting_dir.mkdir(parents=True, exist_ok=True)

    content = await file.read()
    try:
        text = content.decode("utf-8")
    except UnicodeDecodeError:
        text = content.decode("gbk", errors="replace")

    dest = "transcript" + ext
    (meeting_dir / dest).write_text(text, encoding="utf-8")
    _write_meeting_meta(
        meeting_id,
        {
            "name": name,
            "created_at": time.strftime("%Y-%m-%d %H:%M:%S"),
            "original_filename": file.filename,
        },
    )
    _set_active_meeting(meeting_id)
    return {"id": meeting_id, "name": name}


@app.delete("/api/meetings/{meeting_id}")
async def delete_meeting(meeting_id: str):
    if not (DATA_DIR / meeting_id).exists():
        raise HTTPException(404, "Meeting not found")

    active_meeting_id = _load_app_state().get("active_meeting_id")
    for base in (DATA_DIR, RESULTS_MD_DIR, RESULTS_JSON_DIR):
        meeting_dir = base / meeting_id
        if meeting_dir.exists():
            shutil.rmtree(str(meeting_dir))

    if active_meeting_id == meeting_id:
        remaining = _list_meeting_ids()
        _set_active_meeting(remaining[0] if remaining else None)
    return {"ok": True}


@app.delete("/api/meetings/{meeting_id}/results")
async def delete_meeting_results(meeting_id: str):
    deleted = False
    for base in (RESULTS_MD_DIR, RESULTS_JSON_DIR):
        meeting_dir = base / meeting_id
        if meeting_dir.exists():
            shutil.rmtree(str(meeting_dir))
            deleted = True
    if not deleted:
        raise HTTPException(404, "Meeting results not found")
    return {"ok": True}


@app.get("/api/meetings/{meeting_id}/file/{filename:path}")
async def get_meeting_file(meeting_id: str, filename: str):
    for base in (DATA_DIR, RESULTS_MD_DIR, RESULTS_JSON_DIR):
        fp = base / meeting_id / filename
        if fp.exists():
            return {"content": fp.read_text(encoding="utf-8"), "filename": filename}
    raise HTTPException(404, f"File not found: {filename}")


@app.get("/api/examples/{filename:path}")
async def get_example_file(filename: str):
    fp = EXAMPLES_DIR / filename
    if not fp.exists():
        raise HTTPException(404, f"File not found: {filename}")
    return {"content": fp.read_text(encoding="utf-8"), "filename": filename}


@app.get("/api/templates")
async def list_templates():
    templates = []
    if TEMPLATE_DIR.exists():
        for f in sorted(TEMPLATE_DIR.iterdir()):
            if f.is_file() and f.suffix == ".md":
                templates.append({"name": f.name, "has_guide": _guide_path(f.name).exists()})
    return templates


@app.get("/api/templates/{name}")
async def get_template(name: str):
    fp = _resolve_child(TEMPLATE_DIR, name)
    if not fp.exists():
        raise HTTPException(404, f"Template not found: {name}")
    return {
        "name": name,
        "content": fp.read_text(encoding="utf-8"),
        "has_guide": _guide_path(name).exists(),
    }


@app.put("/api/templates/{name}")
async def save_template(name: str, payload: dict):
    content = payload.get("content")
    if content is None:
        raise HTTPException(400, "Missing content field")
    _resolve_child(TEMPLATE_DIR, name).write_text(content, encoding="utf-8")
    return {"ok": True}


@app.delete("/api/templates/{name}")
async def delete_template(name: str):
    template_path = _resolve_child(TEMPLATE_DIR, name)
    if not template_path.exists():
        raise HTTPException(404, f"Template not found: {name}")
    template_path.unlink()

    guide_path = _guide_path(name)
    if guide_path.exists():
        guide_path.unlink()
    return {"ok": True}


@app.get("/api/templates/{name}/guide")
async def get_template_guide(name: str):
    template_path = _resolve_child(TEMPLATE_DIR, name)
    if not template_path.exists():
        raise HTTPException(404, f"Template not found: {name}")
    guide_path = _guide_path(name)
    if not guide_path.exists():
        raise HTTPException(404, f"Template guide not found: {name}")
    content = guide_path.read_text(encoding="utf-8")
    return {"name": name, "content": content}


@app.put("/api/templates/{name}/guide")
async def save_template_guide(name: str, payload: dict):
    content = payload.get("content")
    if content is None:
        raise HTTPException(400, "Missing content field")
    template_path = _resolve_child(TEMPLATE_DIR, name)
    if not template_path.exists():
        raise HTTPException(404, f"Template not found: {name}")
    with _get_template_lock(name):
        _guide_path(name).write_text(content, encoding="utf-8")
    return {"ok": True}


@app.post("/api/templates/{name}/guide/reparse")
async def reparse_template_guide(name: str):
    content = _ensure_template_guide(name, force=True)
    return {"name": name, "content": content}


@app.get("/api/prompts")
async def list_prompts():
    prompts = []
    if PROMPT_DIR.exists():
        for f in sorted(PROMPT_DIR.iterdir()):
            if f.is_file() and f.suffix in {".yaml", ".yml"}:
                prompts.append({"name": f.name})
    return prompts


@app.get("/api/prompts/{name}")
async def get_prompt(name: str):
    fp = _resolve_child(PROMPT_DIR, name)
    if not fp.exists():
        raise HTTPException(404, f"Prompt not found: {name}")
    return {"name": name, "content": fp.read_text(encoding="utf-8")}


@app.put("/api/prompts/{name}")
async def save_prompt(name: str, payload: dict):
    content = payload.get("content")
    if content is None:
        raise HTTPException(400, "Missing content field")
    _resolve_child(PROMPT_DIR, name).write_text(content, encoding="utf-8")
    return {"ok": True}


@app.get("/api/meetings/{meeting_id}/transcript")
async def get_meeting_transcript(meeting_id: str):
    fp = _find_transcript_file(meeting_id)
    if fp:
        return {"content": fp.read_text(encoding="utf-8"), "filename": fp.name}
    raise HTTPException(404, "No transcript found")


@app.put("/api/meetings/{meeting_id}/summary")
async def save_meeting_summary(meeting_id: str, payload: dict):
    content = payload.get("content")
    if content is None:
        raise HTTPException(400, "Missing content field")
    if not (DATA_DIR / meeting_id).exists():
        raise HTTPException(404, "Meeting not found")

    summary_dir = RESULTS_MD_DIR / meeting_id
    summary_dir.mkdir(parents=True, exist_ok=True)
    (summary_dir / "meeting_summary.md").write_text(content, encoding="utf-8")
    return {"ok": True}


@app.get("/api/meetings/{meeting_id}/process")
async def process_meeting(meeting_id: str, request: Request, template_name: str = "template1.md"):
    meeting_dir = DATA_DIR / meeting_id
    if not meeting_dir.exists():
        raise HTTPException(404, "Meeting not found")
    _set_active_meeting(meeting_id)

    transcript_file = _find_transcript_file(meeting_id)
    if transcript_file is None:
        raise HTTPException(400, "No transcript found")
    transcript = transcript_file.read_text(encoding="utf-8")

    template_path = _resolve_child(TEMPLATE_DIR, template_name)
    if not template_path.exists():
        raise HTTPException(404, f"Template not found: {template_name}")
    template_content = template_path.read_text(encoding="utf-8")
    template_guide = _ensure_template_guide(template_name)

    prompt = load_prompt("meeting_summary", "zh")
    cfg = _load_config()
    model_name = cfg["model_name"]
    events = queue.Queue()

    def run():
        try:
            client = _get_llm_client(cfg)

            events.put({"type": "status", "data": "preprocessing"})
            system_prompt = prompt["system"]["role"] + prompt["mode_contracts"]["data_preproces"]
            user_prompt = prompt["user_template"]["article_preproces"].format(article=transcript)

            sub_topics = ""
            for chunk_type, chunk_content in _llm_stream(client, model_name, system_prompt, user_prompt):
                if chunk_content:
                    text = str(chunk_content)
                    events.put({"type": "chunk", "data": {"stage": 1, "chunk_type": chunk_type, "text": text}})
                    if chunk_type == "content":
                        sub_topics += text

            events.put({"type": "status", "data": "preprocessing_done"})

            results_json_dir = RESULTS_JSON_DIR / meeting_id
            results_json_dir.mkdir(parents=True, exist_ok=True)
            try:
                data = json.loads(sub_topics)
                (results_json_dir / "sub_topic.json").write_text(
                    json.dumps(data, ensure_ascii=False, indent=4),
                    encoding="utf-8",
                )
            except Exception:
                (results_json_dir / "sub_topic.json").write_text(sub_topics, encoding="utf-8")

            events.put({"type": "status", "data": "summarizing"})
            system_prompt = prompt["system"]["role"] + prompt["mode_contracts"]["data_summary"].format(
                template=template_content
            )
            if template_guide:
                system_prompt += f"\n\n模板使用说明：\n{template_guide}"
            user_prompt = prompt["user_template"]["article_summary"].format(
                article=transcript,
                sub_topices=sub_topics,
            )

            result = ""
            for chunk_type, chunk_content in _llm_stream(client, model_name, system_prompt, user_prompt):
                if chunk_content:
                    text = str(chunk_content)
                    events.put({"type": "chunk", "data": {"stage": 2, "chunk_type": chunk_type, "text": text}})
                    if chunk_type == "content":
                        result += text

            results_md_dir = RESULTS_MD_DIR / meeting_id
            results_md_dir.mkdir(parents=True, exist_ok=True)
            (results_md_dir / "meeting_summary.md").write_text(result, encoding="utf-8")
            events.put({"type": "done", "data": {"result": result}})
        except Exception as exc:
            events.put({"type": "error", "data": str(exc)})

    threading.Thread(target=run, daemon=True).start()

    async def gen():
        loop = asyncio.get_running_loop()
        while True:
            if await request.is_disconnected():
                break
            try:
                event = await loop.run_in_executor(None, events.get, True, 0.5)
                yield f"data: {json.dumps(event, ensure_ascii=False)}\n\n"
                if event["type"] in {"done", "error"}:
                    break
            except queue.Empty:
                yield ": heartbeat\n\n"

    return StreamingResponse(
        gen(),
        media_type="text/event-stream",
        headers={
            "Cache-Control": "no-cache",
            "X-Accel-Buffering": "no",
            "Connection": "keep-alive",
        },
    )


if __name__ == "__main__":
    import uvicorn

    uvicorn.run(app, host="0.0.0.0", port=8000)