# IR 生成、验证、Diff 接口

import asyncio
import json
import logging
from concurrent.futures import ThreadPoolExecutor

from fastapi import APIRouter, HTTPException, Query
from fastapi.responses import StreamingResponse

from server.services.ir_engine.generator import ir_generator
from server.services.ir_engine.pipeline import ir_pipeline
from server.services.ir_engine.validator import ir_validator
from server.services.ir_engine.diff import ir_diff
from server.services.prd_manager.service import prd_service

logger = logging.getLogger(__name__)
router = APIRouter()

_pipeline_executor = ThreadPoolExecutor(max_workers=2)


@router.get("/generate-stream")
async def generate_ir_stream(prd_id: str = Query(...), skill_name: str = "default"):
    """基于 PRD 生成 IR，通过 SSE 流式返回进度"""
    prd = await prd_service.get_prd(prd_id)
    if not prd:
        raise HTTPException(404, "PRD not found")

    async def event_stream():
        # Wait for background parsing if still in progress
        if prd.get("status") == "parsing":
            yield f"data: {json.dumps({'stage': 0, 'status': 'running', 'message': '文档解析中，请稍候...', 'detail': '图片分析可能需要 30-60 秒', 'stage_total': 4})}\n\n"
            waited = 0
            while waited < 120:
                await asyncio.sleep(1)
                waited += 1
                p = await prd_service.get_prd(prd_id)
                if not p or p.get("status") in ("ready", "error"):
                    break
                if waited % 5 == 0:
                    yield f"data: {json.dumps({'stage': 0, 'status': 'running', 'message': f'文档解析中...({waited}s)', 'stage_total': 4})}\n\n"
            p = await prd_service.get_prd(prd_id)
            if p and p.get("status") == "error":
                yield f"data: {json.dumps({'error': p.get('error', '解析失败'), 'stage_total': 4})}\n\n"
                return

        # Reload after parsing
        prd2 = await prd_service.get_prd(prd_id)
        parsed_doc = _load_parsed_doc(prd2 or prd)
        if not parsed_doc:
            yield f"data: {json.dumps({'error': '无法加载解析后的文档'})}\n\n"
            return

        yield f"data: {json.dumps({'stage': 0, 'status': 'done', 'message': '文档解析完成', 'stage_total': 4})}\n\n"

        # Run pipeline in thread → Queue → SSE
        queue: asyncio.Queue = asyncio.Queue()

        def _run_in_thread():
            try:
                for event in ir_pipeline.run_streaming(prd_id, parsed_doc):
                    queue.put_nowait(event)
            except Exception as e:
                logger.exception("Pipeline error")
                queue.put_nowait({"error": str(e), "done": True})
            finally:
                queue.put_nowait(None)

        loop = asyncio.get_event_loop()
        loop.run_in_executor(_pipeline_executor, _run_in_thread)

        while True:
            event = await queue.get()
            if event is None:
                break
            yield f"data: {json.dumps(event, ensure_ascii=False)}\n\n"
        yield "data: {\"done\": true}\n\n"

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


def _load_parsed_doc(prd: dict) -> dict | None:
    """Load parsed document from disk or build from PRD data."""
    import os as _os
    parsed_path = prd.get("parsed_path", "")
    if parsed_path and _os.path.isfile(parsed_path):
        try:
            with open(parsed_path, "r", encoding="utf-8") as f:
                return json.load(f)
        except Exception:
            pass

    sections = prd.get("sections", [])
    if not sections and prd.get("full_text"):
        sections = [{"source": "正文", "blocks": [{"type": "para", "index": 1, "text": prd["full_text"]}], "images": []}]

    if sections or prd.get("full_text"):
        return {
            "source": "",
            "sections": sections,
            "image_sources": {},
            "image_analysis": prd.get("images", []),
            "resolved_conflicts": [],
        }
    return None


@router.post("/generate")
async def generate_ir(prd_id: str, skill_name: str = "default"):
    """基于 PRD 和 Skill 生成 IR"""
    prd = await prd_service.get_prd(prd_id)
    if not prd:
        raise HTTPException(404, "PRD not found")

    prd_text = prd.get("full_text", "")
    if not prd_text:
        raise HTTPException(400, "PRD has no text content")

    result = await ir_generator.generate(prd_id, prd_text, skill_name)
    if "error" in result:
        raise HTTPException(500, result["error"])

    return {
        "ir_id": result["ir_id"],
        "prd_id": result["prd_id"],
        "yaml_content": result["yaml_content"],
        "ir_json": result.get("ir_json", {}),
        "audit": result.get("audit", {}),
        "audit_report": result.get("audit_report", ""),
        "skill_used": result["skill_used"],
        "created_at": result["created_at"],
        "pipeline_stats": result.get("pipeline_stats", {}),
    }


@router.get("/{ir_id}")
async def get_ir(ir_id: str):
    """获取 IR 详情"""
    ir = await ir_generator.get_ir(ir_id)
    if not ir:
        raise HTTPException(404, "IR not found")
    return ir


@router.put("/{ir_id}")
async def update_ir(ir_id: str, body: dict):
    """更新 IR 内容（编辑后同步回后端）"""
    ir = await ir_generator.get_ir(ir_id)
    if not ir:
        raise HTTPException(404, "IR not found")
    new_content = body.get("yaml_content", "")
    if new_content:
        ir["yaml_content"] = new_content
        try:
            ir["ir_json"] = json.loads(new_content)
        except json.JSONDecodeError:
            pass
    return {"ir_id": ir_id, "status": "updated"}


@router.post("/{ir_id}/validate")
async def validate_ir(ir_id: str):
    """验证 IR 是否符合 Schema 和 Principles"""
    ir = await ir_generator.get_ir(ir_id)
    if not ir:
        raise HTTPException(404, "IR not found")

    result = await ir_validator.validate(ir["yaml_content"], ir.get("skill_used", "default"))
    return {
        "ir_id": ir_id,
        "valid": result["valid"],
        "issues": result["issues"],
    }


@router.get("/diff")
async def diff_ir(ir_id_a: str, ir_id_b: str):
    """对比两个 IR 版本的差异"""
    result = await ir_diff.diff(ir_id_a, ir_id_b)
    if "error" in result:
        raise HTTPException(400, result["error"])
    return result