# -*- coding: utf-8 -*-
"""个性化推荐模块：习题测评、错题集、学情分析"""
from datetime import datetime

from fastapi import APIRouter, Depends
from pydantic import BaseModel
from sqlalchemy.orm import Session

from backend.database import get_db
from backend.models import Question, AnswerRecord
from backend.services.auth import get_current_user_id
from backend.services.recommendation import (
    get_user_proficiency,
    get_recommended_questions,
    get_or_generate_daily_recommendations,
    get_mastery_matrix,
    get_motivation_summary,
    get_question_analysis,
    get_wrong_questions_for_user,
    get_diagnostic_questions,
)
from backend.services.mastery_service import (
    update_mastery_from_answers,
    mark_daily_recommendations_done,
)
from backend.models import WrongQuestion
from backend.models import DailyRecommendation

router = APIRouter(prefix="/recommendation", tags=["个性化推荐"])


@router.get("/proficiency")
def proficiency(
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """知识点熟练度（学情报表）"""
    return get_user_proficiency(db, user_id)


@router.get("/wrong_questions")
def wrong_questions(
    limit: int = 50,
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """错题集"""
    questions = get_wrong_questions_for_user(db, user_id, limit=limit)
    return [
        {
            "id": q.id,
            "content": q.content,
            "option_a": q.option_a,
            "option_b": q.option_b,
            "option_c": q.option_c,
            "option_d": q.option_d,
            "knowledge_point": q.knowledge_point,
        }
        for q in questions
    ]


@router.get("/recommended_questions")
def recommended_questions(
    count: int = 5,
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """习题测评推荐算法（错题优先 + 薄弱知识点）"""
    qs = get_recommended_questions(db, user_id, count)
    return [{"id": q.id, "content": q.content, "option_a": q.option_a, "option_b": q.option_b,
             "option_c": q.option_c, "option_d": q.option_d, "knowledge_point": q.knowledge_point}
            for q in qs]


@router.get("/daily_practice")
def daily_practice(
    count: int = 10,
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """每日一练：按弱点权重生成今日推荐题，若今日已有则直接返回"""
    qs = get_or_generate_daily_recommendations(db, user_id, count=count)
    return [{"id": q.id, "content": q.content, "option_a": q.option_a, "option_b": q.option_b,
             "option_c": q.option_c, "option_d": q.option_d, "knowledge_point": q.knowledge_point}
            for q in qs]


@router.get("/mastery_matrix")
def mastery_matrix(
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """知识点掌握度矩阵：用于前端颜色分级、雷达图等可视化"""
    return get_mastery_matrix(db, user_id)


@router.get("/motivation_summary")
def motivation_summary(
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """激励信息汇总：连续打卡天数、全绿模块、章节平均掌握度"""
    return get_motivation_summary(db, user_id)


@router.get("/question_analysis")
def question_analysis(
    question_id: int,
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """题目解析：从 chemistry_question_bank.analysis 读取。"""
    _ = user_id
    analysis = get_question_analysis(db, question_id)
    return {"question_id": question_id, "analysis": analysis}


class SubmitAnswerRequest(BaseModel):
    question_id: int
    selected_option: str


@router.post("/submit_answer")
def submit_answer(
    req: SubmitAnswerRequest,
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """提交单题答案（答题记录）"""
    q = db.query(Question).get(req.question_id)
    if not q:
        return {"ok": False, "error": "题目不存在"}
    is_correct = req.selected_option == q.correct_option
    rec = AnswerRecord(user_id=user_id, question_id=q.id, selected_option=req.selected_option, is_correct=is_correct)
    db.add(rec)
    db.commit()
    return {"ok": True, "is_correct": is_correct}


class SubmitBatchRequest(BaseModel):
    answers: list[dict]  # [{"question_id": 1, "selected_option": "A"}, ...]


class DiagnosticSubmitRequest(BaseModel):
    answers: list[dict]  # [{"question_id": 1, "selected_option": "A"}, ...]
    train_count: int = 10
    regenerate_daily: bool = False


@router.post("/submit_batch")
def submit_batch(
    req: SubmitBatchRequest,
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """批量提交（每日训练），同时更新弱点权重与掌握度"""
    correct, total = 0, 0
    processed = []
    answer_record_ids = {}  # {question_id: answer_records.id}
    for item in req.answers:
        q = db.query(Question).get(item.get("question_id"))
        if not q:
            continue
        sel = item.get("selected_option", "")
        is_correct = sel == q.correct_option
        total += 1
        if is_correct:
            correct += 1
        rec = AnswerRecord(
            user_id=user_id,
            question_id=q.id,
            selected_option=sel,
            is_correct=is_correct,
        )
        db.add(rec)
        # 获取 rec.id，后续写回 daily_recommendations.answer_record_id
        db.flush()
        answer_record_ids[q.id] = rec.id

        # 第二阶段：记录错题集到 wrong_questions（用于错题→变式题闭环）
        if not is_correct:
            try:
                wq = (
                    db.query(WrongQuestion)
                    .filter(
                        WrongQuestion.user_id == user_id,
                        WrongQuestion.question_id == q.id,
                    )
                    .first()
                )
                if not wq:
                    wq = WrongQuestion(
                        user_id=user_id,
                        question_id=q.id,
                        wrong_count=1,
                        last_wrong_at=datetime.utcnow(),
                    )
                    db.add(wq)
                else:
                    wq.wrong_count = (wq.wrong_count or 0) + 1
                    wq.last_wrong_at = datetime.utcnow()
            except Exception:
                # 不影响主流程：错题集写入失败时仍允许学习闭环继续
                pass

        processed.append({"question_id": q.id, "selected_option": sel})
    if total > 0:
        try:
            update_mastery_from_answers(db, user_id, processed, session_kind="practice")
            from datetime import date
            mark_daily_recommendations_done(
                db, user_id,
                [a["question_id"] for a in processed],
                today=date.today(),
                answer_record_ids=answer_record_ids,
            )
        except Exception:
            pass
        db.commit()
    acc = int(round(correct / total * 100)) if total else 0
    return {"ok": True, "total": total, "correct": correct, "accuracy": acc}


@router.get("/diagnostic_questions")
def diagnostic_questions(
    count: int = 10,
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """诊断测评：覆盖广、难度适中（用于弱点更新）"""
    qs = get_diagnostic_questions(db, user_id, count=count, session_kind="diagnostic")
    return [
        {
            "id": q.id,
            "content": q.content,
            "option_a": q.option_a,
            "option_b": q.option_b,
            "option_c": q.option_c,
            "option_d": q.option_d,
            "knowledge_point": q.knowledge_point,
        }
        for q in qs
    ]


@router.get("/re_evaluate_questions")
def re_evaluate_questions(
    count: int = 10,
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """再测评：在测评后/训练后重新抽取题目"""
    qs = get_diagnostic_questions(db, user_id, count=count, session_kind="re_evaluate")
    return [
        {
            "id": q.id,
            "content": q.content,
            "option_a": q.option_a,
            "option_b": q.option_b,
            "option_c": q.option_c,
            "option_d": q.option_d,
            "knowledge_point": q.knowledge_point,
        }
        for q in qs
    ]


@router.post("/diagnostic_submit_batch")
def diagnostic_submit_batch(
    req: DiagnosticSubmitRequest,
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """
    诊断测评提交：
    - 写入 answer_records
    - 按弱点更新规则更新 student_knowledge_mastery
    - 生成（或复用）每日一练 daily_recommendations（train_count）
    """
    correct, total = 0, 0
    processed: list[dict] = []

    # 1) 写入答题记录（同时更新 wrong_questions 聚合）
    for item in req.answers:
        try:
            qid = int(item.get("question_id"))
        except (TypeError, ValueError):
            continue
        selected = (item.get("selected_option") or "").strip()
        if not selected:
            continue

        q = db.query(Question).get(qid)
        if not q:
            continue

        is_correct = selected == q.correct_option
        total += 1
        if is_correct:
            correct += 1

        db.add(
            AnswerRecord(
                user_id=user_id,
                question_id=q.id,
                selected_option=selected,
                is_correct=is_correct,
            )
        )

        if not is_correct:
            try:
                wq = (
                    db.query(WrongQuestion)
                    .filter(WrongQuestion.user_id == user_id, WrongQuestion.question_id == q.id)
                    .first()
                )
                if not wq:
                    db.add(
                        WrongQuestion(
                            user_id=user_id,
                            question_id=q.id,
                            wrong_count=1,
                            last_wrong_at=datetime.utcnow(),
                        )
                    )
                else:
                    wq.wrong_count = (wq.wrong_count or 0) + 1
                    wq.last_wrong_at = datetime.utcnow()
            except Exception:
                pass

        processed.append({"question_id": q.id, "selected_option": selected})

    if total == 0:
        return {"ok": False, "detail": "未提交有效答题"}

    db.commit()

    # 2) 更新弱点/掌握度（批量测评结束后统一更新）
    update_mastery_from_answers(db, user_id, processed, session_kind="diagnostic")
    db.commit()

    # 3) 生成每日一练（闭环：测评→推荐）
    from datetime import date

    today = date.today()
    if req.regenerate_daily:
        db.query(DailyRecommendation).filter(
            DailyRecommendation.user_id == user_id,
            DailyRecommendation.recommend_date == today,
            DailyRecommendation.is_done == 0,
        ).delete(synchronize_session=False)
        db.commit()

    daily_qs = get_or_generate_daily_recommendations(
        db, user_id, count=req.train_count, today=today
    )

    # 返回：测评结果 + 当天每日一练题目
    acc = int(round(correct / total * 100))
    return {
        "ok": True,
        "diagnostic": {"total": total, "correct": correct, "accuracy": acc},
        "daily_practice": [
            {
                "id": q.id,
                "content": q.content,
                "option_a": q.option_a,
                "option_b": q.option_b,
                "option_c": q.option_c,
                "option_d": q.option_d,
                "knowledge_point": q.knowledge_point,
            }
            for q in daily_qs
        ],
    }


@router.post("/re_evaluate_submit_batch")
def re_evaluate_submit_batch(
    req: DiagnosticSubmitRequest,
    db: Session = Depends(get_db),
    user_id: int = Depends(get_current_user_id),
):
    """再测评提交：同诊断提交逻辑，然后给出下一轮每日一练"""
    resp = diagnostic_submit_batch(
        req=req,
        db=db,
        user_id=user_id,
    )
    return resp