"""BI报表集成 — 任务4
分析模式 + 预置报表模板 + 报表保存/分享 + 导出
"""
from fastapi import APIRouter, Depends, HTTPException, Query
from fastapi.responses import Response
from sqlalchemy.orm import Session
from typing import Optional, List
from datetime import datetime
import json
import logging

from app.database import get_db
from app.auth_middleware import require_auth, require_role
from app.models import KPIDefinition, KPIValue, BiReportTemplate, BiReport, OperationLog, KPICausality

logger = logging.getLogger("bi-reports")

router = APIRouter(prefix="/api/cma/bi-reports", tags=["BI报表"],
    dependencies=[Depends(require_role("ceo", "finance", "business", "it"))],
)
WRITE_ROLES = Depends(require_role("ceo", "finance", "it"))


# ============================================================
# 预置模板
# ============================================================

PRESET_TEMPLATES = [
    {
        "name": "四层指标总览",
        "report_type": "overview",
        "is_system": 1,
        "config": {
            "description": "展示财务/客户/流程/学习四层维度的关键KPI概览",
            "layout": "grid",
            "dimensions": ["finance", "customer", "process", "learning"],
            "metrics": ["count", "avg_value", "alert_count"],
            "chart_type": "gauge_card",
        }
    },
    {
        "name": "同比趋势分析",
        "report_type": "trend",
        "is_system": 1,
        "config": {
            "description": "各KPI近12个月趋势对比",
            "period": "monthly",
            "window_months": 12,
            "chart_type": "line",
            "show_compare": True,
        }
    },
    {
        "name": "实际vs预算对比",
        "report_type": "comparison",
        "is_system": 1,
        "config": {
            "description": "KPI实际值 vs 目标值的偏差分析",
            "chart_type": "bar",
            "show_deviation": True,
            "group_by": "dimension",
        }
    },
    {
        "name": "TOP N异常KPI",
        "report_type": "topn",
        "is_system": 1,
        "config": {
            "description": "排名前N的异常KPI（红/黄灯）",
            "top_n": 10,
            "sort_by": "deviation",
            "chart_type": "horizontal_bar",
            "show_threshold": True,
        }
    },
    {
        "name": "因果链推演",
        "report_type": "causality",
        "is_system": 1,
        "config": {
            "description": "基于KPI因果链的推演分析",
            "chart_type": "force_graph",
            "max_depth": 3,
            "min_strength": 0.3,
        }
    },
]


@router.get("/templates")
def list_report_templates(db: Session = Depends(get_db)):
    """获取BI报表模板"""
    templates = db.query(BiReportTemplate).order_by(BiReportTemplate.id).all()
    return {"data": [{c.name: getattr(t, c.name) for c in BiReportTemplate.__table__.columns} for t in templates]}


@router.post("/templates/seed")
def seed_report_templates(db: Session = Depends(get_db), user=WRITE_ROLES):
    """初始化预置模板（仅首次运行）"""
    created = 0
    for tpl in PRESET_TEMPLATES:
        existing = db.query(BiReportTemplate).filter(
            BiReportTemplate.name == tpl["name"],
            BiReportTemplate.is_system == 1,
        ).first()
        if existing:
            continue
        t = BiReportTemplate(**tpl)
        db.add(t)
        created += 1
    db.commit()
    return {"message": f"新增{created}个预置模板", "created": created}


@router.delete("/templates/{template_id}")
def delete_template(template_id: int, db: Session = Depends(get_db), user=WRITE_ROLES):
    t = db.query(BiReportTemplate).filter(BiReportTemplate.id == template_id).first()
    if t:
        db.delete(t)
        db.commit()
    return {"message": "已删除"}


# ============================================================
# 用户报表
# ============================================================

@router.get("")
def list_reports(db: Session = Depends(get_db)):
    """获取用户保存的报表"""
    reports = db.query(BiReport).order_by(BiReport.updated_at.desc()).all()
    result = []
    for r in reports:
        d = {c.name: getattr(r, c.name) for c in BiReport.__table__.columns}
        d["created_by_name"] = f"用户{r.created_by}" if r.created_by else "系统"
        result.append(d)
    return {"data": result, "total": len(result)}


@router.get("/{report_id}")
def get_report(report_id: int, db: Session = Depends(get_db)):
    r = db.query(BiReport).filter(BiReport.id == report_id).first()
    if not r:
        raise HTTPException(404, "报表不存在")
    return {c.name: getattr(r, c.name) for c in BiReport.__table__.columns}


@router.post("")
def create_report(data: dict, db: Session = Depends(get_db), user=WRITE_ROLES):
    """保存BI报表"""
    r = BiReport(
        template_id=data.get("template_id"),
        name=data.get("name", "未命名报表"),
        config=data.get("config", {}),
        chart_type=data.get("chart_type", "auto"),
        is_shared=data.get("is_shared", 0),
        created_by=1,
    )
    db.add(r)
    db.commit()
    db.refresh(r)
    db.add(OperationLog(action="create", target_type="bi_report", detail=f"创建报表: {r.name}"))
    db.commit()
    return {c.name: getattr(r, c.name) for c in BiReport.__table__.columns}


@router.put("/{report_id}")
def update_report(report_id: int, data: dict, db: Session = Depends(get_db), user=WRITE_ROLES):
    r = db.query(BiReport).filter(BiReport.id == report_id).first()
    if not r:
        raise HTTPException(404, "报表不存在")
    for field in ("name", "config", "chart_type", "is_shared"):
        if field in data:
            setattr(r, field, data[field])
    db.commit()
    return {c.name: getattr(r, c.name) for c in BiReport.__table__.columns}


@router.delete("/{report_id}")
def delete_report(report_id: int, db: Session = Depends(get_db), user=WRITE_ROLES):
    r = db.query(BiReport).filter(BiReport.id == report_id).first()
    if r:
        db.delete(r)
        db.commit()
    return {"message": "已删除"}


# ============================================================
# 分析引擎
# ============================================================

@router.post("/analyze")
def analyze_data(data: dict, db: Session = Depends(get_db)):
    """分析引擎：按配置返回报表数据
    Body: {
        config: { dimensions, kpi_ids, period_start, period_end, group_by, metrics, ... },
        chart_type: str
    }
    """
    config = data.get("config", {})
    chart_type = data.get("chart_type", "auto")

    kpi_ids = config.get("kpi_ids", [])
    dimensions = config.get("dimensions", [])
    period_start = config.get("period_start")
    period_end = config.get("period_end")
    group_by = config.get("group_by")
    top_n = config.get("top_n", 10)

    # 构建KPI查询
    kpi_query = db.query(KPIDefinition).filter(KPIDefinition.status == "active")
    if kpi_ids:
        kpi_query = kpi_query.filter(KPIDefinition.id.in_(kpi_ids))
    if dimensions:
        kpi_query = kpi_query.filter(KPIDefinition.dimension.in_(dimensions))
    kpis = kpi_query.order_by(KPIDefinition.kpi_code).all()

    # 获取每个KPI的最新值
    rows = []
    for kpi in kpis:
        val_query = db.query(KPIValue).filter(
            KPIValue.kpi_id == kpi.id,
            KPIValue.actual_value.isnot(None),
        )
        if period_start:
            val_query = val_query.filter(KPIValue.period >= period_start)
        if period_end:
            val_query = val_query.filter(KPIValue.period <= period_end)

        latest = val_query.order_by(KPIValue.period.desc()).first()

        # 获取趋势数据
        trend_values = val_query.order_by(KPIValue.period.asc()).limit(12).all()

        rows.append({
            "kpi_id": kpi.id,
            "kpi_code": kpi.kpi_code,
            "kpi_name": kpi.kpi_name,
            "dimension": kpi.dimension,
            "category": kpi.category,
            "unit": kpi.unit,
            "target_value": kpi.target_value,
            "threshold_green": kpi.threshold_green,
            "threshold_yellow": kpi.threshold_yellow,
            "threshold_red": kpi.threshold_red,
            "current_value": latest.actual_value if latest else None,
            "current_period": latest.period if latest else None,
            "trend": [{"period": v.period, "value": v.actual_value} for v in trend_values],
        })

    # 统计汇总
    summary = {
        "total_kpis": len(rows),
        "dimensions": {},
    }
    for r in rows:
        dim = r["dimension"]
        if dim not in summary["dimensions"]:
            summary["dimensions"][dim] = {"count": 0, "values": []}
        summary["dimensions"][dim]["count"] += 1
        if r["current_value"] is not None:
            summary["dimensions"][dim]["values"].append(r["current_value"])

    for dim, info in summary["dimensions"].items():
        vals = info["values"]
        if vals:
            info["avg"] = round(sum(vals) / len(vals), 2)
            info["min"] = min(vals)
            info["max"] = max(vals)
        del info["values"]

    return {
        "config": config,
        "chart_type": chart_type,
        "rows": rows,
        "summary": summary,
    }


# ============================================================
# 导出功能（CSV格式，前端可转为Excel/PDF）
# ============================================================

@router.post("/export")
def export_report(data: dict, db: Session = Depends(get_db)):
    """导出报表数据 (CSV)"""
    config = data.get("config", {})
    format_type = data.get("format", "csv")

    # 复用analyze获取数据
    from app.database import get_session_local
    temp_db = get_session_local()()
    try:
        result = analyze_data(data, temp_db)
    finally:
        temp_db.close()

    rows = result.get("rows", [])
    if not rows:
        raise HTTPException(400, "没有可导出的数据")

    # 生成CSV
    import csv, io
    output = io.StringIO()
    writer = csv.writer(output)
    writer.writerow(["KPI编码", "KPI名称", "维度", "类别", "当前值", "期间", "目标值", "单位"])
    for r in rows:
        writer.writerow([
            r["kpi_code"], r["kpi_name"], r["dimension"], r["category"],
            r["current_value"], r["current_period"], r["target_value"], r["unit"],
        ])

    csv_content = output.getvalue()
    return Response(
        content=csv_content,
        media_type="text/csv",
        headers={"Content-Disposition": f"attachment; filename=bi_report_{datetime.now().strftime('%Y%m%d')}.csv"},
    )