"""Routes for session-grouped async RAGAS scoring (Dify multi-call integration).

Use case: Dify evaluates multiple Q&A pairs in a session. Each pair gets its own
`POST /api/score/session_async` call with a shared `session_id`. All results are
accumulated into one report, visible in 「运行列表」→「报告详情」.

Key behaviour:
  - Deterministic run_id: derived from session_id — same session always maps to the
    same report directory (outputs/score-session/session-<id>/).
  - Append semantics: each call adds a new sample row. Previous rows are preserved.
  - Advisor regeneration: optimization_advice.md is regenerated after every call
    using the full set of accumulated rows.
  - Each call returns its own `job_id` for individual status polling, plus the
    shared `run_id` and `session_id`.

Endpoints:
  POST /api/score/session_async         Submit one call (returns job_id + run_id)
  GET  /api/score/sessions              List all sessions
  GET  /api/score/sessions/{session_id} Session aggregate (call_count, metric_means, jobs)
  GET  /api/score/session/jobs/{job_id} Status of one individual call
"""

from __future__ import annotations

import logging

from fastapi import APIRouter, HTTPException

from webapp.models import (
    AsyncScoreJobStatus,
    ScoreRequest,
    SessionScoreJobResponse,
    SessionScoreRequest,
    SessionStatus,
)
from webapp.services.session_score_manager import session_score_manager

router = APIRouter(prefix="/api/score", tags=["score"])
logger = logging.getLogger("webapp.api.session_score_jobs")


@router.post(
    "/session_async",
    status_code=202,
    response_model=SessionScoreJobResponse,
    summary="提交 Session 异步评分（多样本批量聚合）",
    description=(
        "**用途**\n"
        "- 适合 Dify 循环节点、批量问答评测、同一对话多轮累计评分。\n"
        "- 相同 `session_id` 的多次调用不会生成多个独立报告，而是持续追加到同一个 session 报告。\n\n"
        "**请求字段说明**\n"
        "- `session_id`：会话唯一标识，同一会话必须保持一致。\n"
        "- `question` / `answer`：本次待评分的问答对。\n"
        "- `contexts`：检索片段拼接字符串，按 `context_separator` 拆分。\n"
        "- `ground_truth`：标准答案，可选；缺失时会自动跳过依赖它的指标。\n"
        "- `metrics`：本次需要计算的指标列表。\n"
        "- `judge_model` / `embedding_model`：可选；为空时回退到系统默认配置。\n\n"
        "**处理行为**\n"
        "1. 服务端立即返回 `202 Accepted`，并生成本次调用的 `job_id`。\n"
        "2. 系统根据 `session_id` 计算固定 `run_id`，格式为 `session-<sanitized-session_id>`。\n"
        "3. 本次评分完成后，会向该 session 的 `scores.csv` 追加一行样本数据。\n"
        "4. 系统会基于当前 session 的全量样本重写 `summary.md`，并重新生成 `optimization_advice.md`。\n"
        "5. 报告可在「运行列表」中按 `run_id` 查看；同一 session 的后续调用会持续增量更新该报告。\n\n"
        "**后续查询接口**\n"
        "- `GET /api/score/session/jobs/{job_id}`：查询本次调用状态与得分。\n"
        "- `GET /api/score/sessions/{session_id}`：查询整个 session 的累计调用次数、指标均值、所有作业记录。\n"
        "- `GET /api/runs/{run_id}`：查看完整评估报告内容。\n\n"
        "**典型请求示例**\n"
        "```json\n"
        "{\n"
        "  \"session_id\": \"dify-session-001\",\n"
        "  \"question\": \"单源CT与双源CT在球管配置上有何本质区别？\",\n"
        "  \"answer\": \"单源CT只有一套球管-探测器系统，双源CT有两套独立的球管-探测器系统。\",\n"
        "  \"contexts\": \"双源CT采用两套管-探测器系统 |||| 单源CT只有一个球管\",\n"
        "  \"context_separator\": \" |||| \",\n"
        "  \"metrics\": [\"answer_relevancy\", \"faithfulness\"],\n"
        "  \"judge_model\": \"gpt-5.5\",\n"
        "  \"embedding_model\": \"text-embedding-3-small\"\n"
        "}\n"
        "```"
    ),
    responses={
        202: {
            "description": (
                "调用已排队，立即返回 job_id + run_id（202 Accepted）。\n\n"
                "相同 `session_id` 的多次调用合并为同一报告，每次调用新增一个样本行。\n"
                "评分完成后，`summary.md` 和 `optimization_advice.md` 增量更新。\n"
                "通过 `GET /api/score/sessions/{session_id}` 查看 session 聚合状态，"
                "通过 `GET /api/score/session/jobs/{job_id}` 查询单次调用状态，"
                "在「运行列表」中查看完整报告（run_id 即 `session-<session_id>` 形式）。"
            ),
            "content": {
                "application/json": {
                    "example": {
                        "job_id": "abc123def456",
                        "session_id": "dify-session-001",
                        "run_id": "session-dify-session-001",
                        "status": "queued",
                        "call_count": 1,
                    }
                }
            },
        },
    },
)
def submit_session_async_score(request: SessionScoreRequest) -> SessionScoreJobResponse:
    """提交 Session 异步 RAGAS 评分，立即返回 job_id。

    相同 `session_id` 的多次调用合并到同一评估报告中，每次调用：
    1. 新增一个样本行到 `scores.csv`
    2. 重写 `summary.md`（包含所有累积样本的指标均值）
    3. 重新生成 `optimization_advice.md`（基于全量样本的 LLM 优化建议）

    **适合 Dify 工作流**：在循环节点中批量调用，所有轮次共用同一 `session_id`，
    最终在 RAGAS 平台「运行列表」中查看完整的批量评估报告。
    """
    logger.info(
        "[session_async] submit  session_id=%s  metrics=%s  has_ctx=%s  has_gt=%s",
        request.session_id,
        request.metrics,
        bool(request.contexts),
        bool(request.ground_truth),
    )

    # Strip session_id to build a plain ScoreRequest for the manager
    score_request = ScoreRequest(
        question=request.question,
        answer=request.answer,
        contexts=request.contexts,
        ground_truth=request.ground_truth,
        context_separator=request.context_separator,
        metrics=request.metrics,
        judge_model=request.judge_model,
        embedding_model=request.embedding_model,
    )

    status, run_id = session_score_manager.submit(request.session_id, score_request)

    # Compute call_count from current session state
    session_status = session_score_manager.get_session(request.session_id)
    call_count = session_status.call_count if session_status else 1

    logger.info(
        "[session_async] queued  job_id=%s  session_id=%s  run_id=%s  call=%d",
        status.job_id, request.session_id, run_id, call_count,
    )
    return SessionScoreJobResponse(
        job_id=status.job_id,
        session_id=request.session_id,
        run_id=run_id,
        status=status.status,
        call_count=call_count,
    )


@router.get(
    "/sessions",
    response_model=dict,
    summary="列出所有 Session 聚合状态",
)
def list_sessions() -> dict:
    """返回所有 session 的聚合状态，按最近完成时间倒序排列。"""
    sessions = session_score_manager.list_sessions()
    logger.info("[session_score] list_sessions  count=%d", len(sessions))
    return {"sessions": [s.model_dump() for s in sessions]}


@router.get(
    "/sessions/{session_id}",
    response_model=SessionStatus,
    summary="查询 Session 聚合状态（指标均值 + 所有调用记录）",
    responses={404: {"description": "指定 session_id 不存在。"}},
)
def get_session(session_id: str) -> SessionStatus:
    """查询 session 的聚合评分状态。

    返回内容：
    - `run_id`：在「运行列表」中查看完整报告
    - `call_count`：本 session 累计调用次数
    - `metric_means`：所有已累积样本的各指标均值（实时读取 scores.csv）
    - `jobs`：本 session 所有调用记录列表
    """
    status = session_score_manager.get_session(session_id)
    if status is None:
        raise HTTPException(status_code=404, detail=f"Session not found: {session_id}")
    return status


@router.get(
    "/session/jobs/{job_id}",
    response_model=AsyncScoreJobStatus,
    summary="查询 Session 单次调用状态",
    responses={404: {"description": "指定 job_id 不存在。"}},
)
def get_session_job(job_id: str) -> AsyncScoreJobStatus:
    """查询 session 评分中某次调用的状态和评分结果。

    `status` 为 `completed` 时，`run_id` 即所属 session 的报告目录，
    `scores` 包含本次调用的各指标得分。
    """
    status = session_score_manager.get_job(job_id)
    if status is None:
        raise HTTPException(
            status_code=404, detail=f"Session score job not found: {job_id}"
        )
    return status