"""统计分析接口（需求 2.6、2.7.2、4.4），统一挂在 /statistics 前缀下。"""

from __future__ import annotations

from typing import Annotated

from fastapi import APIRouter, Query

from app.core.config import settings
from app.core.deps import DbSession, ReadAccount
from app.core.response import Resp, ok
from app.dao.student_dao import StudentDao
from app.schema.common import PageResult
from app.schema.statistics_schema import (
    AllAboveItem,
    ClassAvgDurationItem,
    ClassAvgScoreItem,
    ClassOverviewItem,
    FailDetailItem,
    FunnelItem,
    OverviewOut,
    SalaryTopItem,
    StudentDurationItem,
    VolatilityItem,
)
from app.schema.student_schema import StudentOut
from app.service.statistics_service import StatisticsService

router = APIRouter(prefix="/statistics", tags=["2.6 统计分析"])


# ==================================================================== 2.6.1
@router.get(
    "/students/by-age",
    response_model=Resp[PageResult[StudentOut]],
    summary="2.6.1 动态年龄范围查询（gt/gte/lt/lte/eq/between）",
)
def students_by_age(
    db: DbSession,
    _: ReadAccount,
    operator: Annotated[str, Query(description="gt / gte / lt / lte / eq / ne / between")] = "gte",
    value: Annotated[int | None, Query(ge=1, le=100, description="年龄阈值")] = None,
    value2: Annotated[int | None, Query(ge=1, le=100, description="between 时的第二个值")] = None,
    class_id: Annotated[int | None, Query()] = None,
    gender: Annotated[int | None, Query(ge=1, le=2)] = None,
    status: Annotated[int | None, Query(ge=1, le=3)] = None,
    advisor_id: Annotated[int | None, Query()] = None,
    education: Annotated[str | None, Query()] = None,
    page: Annotated[int, Query(ge=1)] = 1,
    page_size: Annotated[int, Query(ge=1, le=200)] = 10,
    order_by: Annotated[str, Query(description="支持按 age 排序")] = "age",
    order: Annotated[str, Query(pattern="^(asc|desc)$")] = "asc",
):
    stmt = StatisticsService.age_query(
        db, operator, value, value2,
        class_id=class_id, gender=gender, status=status, advisor_id=advisor_id,
        education=education, order_by=order_by, order=order,
    )
    items, total, page, pages = StudentDao.paginate(db, stmt, page, page_size)
    return ok({
        "total": total, "page": page, "page_size": page_size, "pages": pages,
        "items": [StudentOut.model_validate(s) for s in items],
    })


@router.get("/classes/overview", response_model=Resp[list[ClassOverviewItem]], summary="2.6.1 多维度班级统计（人数 + 性别分布）")
def class_overview(db: DbSession, _: ReadAccount):
    return ok(StatisticsService.class_overview(db))


@router.get("/students/age-distribution", summary="年龄分布（图表用）")
def age_distribution(db: DbSession, _: ReadAccount):
    from app.dao.statistics_dao import StatisticsDao

    return ok(StatisticsDao.age_distribution(db))


# ==================================================================== 2.6.2
@router.get("/scores/all-above", response_model=Resp[list[AllAboveItem]], summary="2.6.2 每次考核都在分数线以上的学生")
def scores_all_above(
    db: DbSession,
    _: ReadAccount,
    threshold: Annotated[float, Query(ge=0, le=1000, description="分数线")] = 80,
    class_id: Annotated[int | None, Query()] = None,
):
    rows = StatisticsService.all_above(db, threshold, class_id)
    return ok(rows, msg=f"{threshold:g} 分以上（每次考核都达标）的学生共 {len(rows)} 人")


@router.get("/scores/failures", response_model=Resp[list[FailDetailItem]], summary="2.6.2 不及格次数达到 N 次的学生及明细")
def score_failures(
    db: DbSession,
    _: ReadAccount,
    threshold: Annotated[float, Query(ge=0, le=1000, description="不及格线")] = 60,
    min_times: Annotated[int, Query(ge=1, le=50, description="至少不及格几次")] = 2,
):
    return ok(StatisticsService.fail_students(db, threshold, min_times))


@router.get("/scores/class-average", response_model=Resp[list[ClassAvgScoreItem]], summary="2.6.2 每场考核每个班级的平均分（可动态排序）")
def class_average(
    db: DbSession,
    _: ReadAccount,
    exam_seq: Annotated[int | None, Query(ge=1, description="只看某一场；不传=全部场次")] = None,
    class_id: Annotated[int | None, Query()] = None,
    order: Annotated[str, Query(pattern="^(asc|desc)$", description="按平均分升降序")] = "desc",
    pass_line: Annotated[float | None, Query(ge=0, le=1000, description="及格线，用于算及格率")] = None,
):
    return ok(
        StatisticsService.class_exam_avg(
            db, exam_seq, class_id, order, pass_line if pass_line is not None else settings.SCORE_PASS_LINE
        )
    )


# ==================================================================== 2.6.3
@router.get("/employment/top-salary", response_model=Resp[list[SalaryTopItem]], summary="2.6.3 就业薪资 Top N")
def top_salary(
    db: DbSession,
    _: ReadAccount,
    top_n: Annotated[int, Query(ge=1, le=100, description="取前几名")] = 5,
):
    return ok(StatisticsService.salary_top(db, top_n))


@router.get("/employment/durations", response_model=Resp[list[StudentDurationItem]], summary="2.6.3 每个学生的就业时长")
def student_durations(
    db: DbSession,
    _: ReadAccount,
    class_id: Annotated[int | None, Query()] = None,
):
    return ok(StatisticsService.student_durations(db, class_id))


@router.get("/employment/class-avg-duration", response_model=Resp[list[ClassAvgDurationItem]], summary="2.6.3 每个班级的平均就业时长")
def class_avg_duration(db: DbSession, _: ReadAccount):
    return ok(StatisticsService.class_avg_duration(db))


# ==================================================================== 2.7.2
@router.get("/scores/volatility", response_model=Resp[list[VolatilityItem]], summary="2.7.2 成绩波动最大的 Top N（标准差 / 最大分差）")
def score_volatility(
    db: DbSession,
    _: ReadAccount,
    top_n: Annotated[int, Query(ge=1, le=50)] = 5,
    metric: Annotated[str, Query(description="stddev=标准差，range=最大分差")] = "stddev",
):
    return ok(StatisticsService.score_volatility(db, top_n, metric))


@router.get("/employment/funnel", response_model=Resp[list[FunnelItem]], summary="2.7.2 班级就业漏斗（按就业率降序）")
def employment_funnel(
    db: DbSession,
    _: ReadAccount,
    high_line: Annotated[float | None, Query(ge=0, description="高薪线，默认取配置值")] = None,
):
    return ok(StatisticsService.employment_funnel(db, high_line))


@router.get("/overview", response_model=Resp[OverviewOut], summary="仪表盘总览")
def overview(db: DbSession, _: ReadAccount):
    return ok(StatisticsService.overview(db))