"""
字段映射 API 端点

提供字段识别、映射确认和规则管理功能
"""

from typing import List, Optional

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.database import get_db
from app.services.auth import AuthService
from app.core.tenant import get_current_company
from app.schemas.mapping import (
    FieldMappingResponse,
    FieldMappingUpdate,
    ConfirmMappingsRequest,
    ConfirmMappingsResponse,
    SaveAsRuleRequest,
    SaveAsRuleResponse,
    CompanyRuleResponse,
    UpdateRuleStatusRequest,
    RecognizeFieldsRequest,
    RecognizeFieldsResponse,
    TaskMappingOverview,
    FileMappingSummary,
)
from app.services.mapping import MappingService
from app.models.user import User
from app.models.company import Company

router = APIRouter(prefix="/mappings", tags=["字段映射"])


def get_mapping_service(db: AsyncSession = Depends(get_db)) -> MappingService:
    return MappingService(db)


@router.post("/recognize", response_model=RecognizeFieldsResponse)
async def recognize_fields(
    request: RecognizeFieldsRequest,
    company_id: int = Depends(get_current_company),
    current_user: User = Depends(AuthService.get_current_user),
    service: MappingService = Depends(get_mapping_service),
):
    """
    触发 AI 字段识别

    - 读取已上传文件的表头和样例数据
    - 调用 AI 识别服务
    - 保存映射建议
    - 返回映射结果
    """
    try:
        mappings = await service.recognize_and_save(
            company_id=company_id,
            file_id=request.file_id,
            file_type=request.file_type
        )

        # 统计置信度分布
        high = sum(1 for m in mappings if m.confidence > 0.9)
        medium = sum(1 for m in mappings if 0.7 <= m.confidence <= 0.9)
        low = sum(1 for m in mappings if m.confidence < 0.7)

        return RecognizeFieldsResponse(
            file_id=request.file_id,
            mappings=[FieldMappingResponse.model_validate(m) for m in mappings],
            high_confidence_count=high,
            medium_confidence_count=medium,
            low_confidence_count=low,
            needs_review=low > 0 or medium > 0
        )
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"字段识别失败: {str(e)}")


@router.get("/task/{task_id}", response_model=TaskMappingOverview)
async def get_task_mappings(
    task_id: int,
    company_id: int = Depends(get_current_company),
    current_user: User = Depends(AuthService.get_current_user),
    service: MappingService = Depends(get_mapping_service),
):
    """
    获取任务的字段映射概览

    - 按文件分组返回所有映射
    - 包含置信度统计
    """
    try:
        grouped_mappings = await service.get_mappings_by_task(task_id, company_id)

        files = []
        total_fields = 0
        confirmed_fields = 0

        for file_id, mappings in grouped_mappings.items():
            file = mappings[0].file if mappings else None
            high = sum(1 for m in mappings if m.confidence > 0.9)
            medium = sum(1 for m in mappings if 0.7 <= m.confidence <= 0.9)
            low = sum(1 for m in mappings if m.confidence < 0.7)

            confirmed = sum(1 for m in mappings if m.confirmed)

            files.append(FileMappingSummary(
                file_id=file_id,
                file_type=file.file_type if file else "",
                file_name=file.original_filename if file else "",
                total_fields=len(mappings),
                confirmed_fields=confirmed,
                high_confidence=high,
                medium_confidence=medium,
                low_confidence=low,
                mappings=[FieldMappingResponse.model_validate(m) for m in mappings]
            ))

            total_fields += len(mappings)
            confirmed_fields += confirmed

        needs_review = any(
            f.medium_confidence > 0 or f.low_confidence > 0
            for f in files
        )

        return TaskMappingOverview(
            task_id=task_id,
            total_files=len(files),
            total_fields=total_fields,
            confirmed_fields=confirmed_fields,
            needs_review=needs_review,
            files=files
        )
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"获取映射失败: {str(e)}")


@router.get("/{mapping_id}", response_model=FieldMappingResponse)
async def get_mapping(
    mapping_id: int,
    current_user: User = Depends(AuthService.get_current_user),
    service: MappingService = Depends(get_mapping_service),
):
    """获取单个字段映射"""
    # 这里需要添加 company_id 检查
    mapping = await service.db.get(mapping_id)
    if not mapping:
        raise HTTPException(status_code=404, detail="映射不存在")

    return FieldMappingResponse.model_validate(mapping)


@router.put("/{mapping_id}", response_model=FieldMappingResponse)
async def update_mapping(
    mapping_id: int,
    update: FieldMappingUpdate,
    current_user: User = Depends(AuthService.get_current_user),
    service: MappingService = Depends(get_mapping_service),
):
    """
    修改字段映射

    - 修改标准字段
    - 标记跳过
    """
    mapping = await service.update_mapping(
        mapping_id=mapping_id,
        standard_field=update.standard_field,
        is_skipped=update.is_skipped
    )

    if not mapping:
        raise HTTPException(status_code=404, detail="映射不存在")

    return FieldMappingResponse.model_validate(mapping)


@router.post("/confirm", response_model=ConfirmMappingsResponse)
async def confirm_mappings(
    request: ConfirmMappingsRequest,
    current_user: User = Depends(AuthService.get_current_user),
    service: MappingService = Depends(get_mapping_service),
):
    """
    批量确认字段映射

    - 确认后映射将用于数据处理
    - 不会自动保存为规则
    """
    confirmed = await service.confirm_mappings(
        mapping_ids=request.mapping_ids,
        user_id=current_user.id
    )

    return ConfirmMappingsResponse(
        confirmed_count=len(confirmed),
        mappings=[FieldMappingResponse.model_validate(m) for m in confirmed]
    )


@router.post("/{mapping_id}/save-as-rule", response_model=SaveAsRuleResponse)
async def save_mapping_as_rule(
    mapping_id: int,
    current_user: User = Depends(AuthService.get_current_user),
    service: MappingService = Depends(get_mapping_service),
):
    """
    将字段映射保存为企业规则

    - 下次上传同类文件时自动应用规则
    - 可在规则管理页面查看和管理
    """
    from app.models.field_mapping import FieldMapping

    # 获取映射
    mapping = await service.db.get(FieldMapping, mapping_id)
    if not mapping:
        raise HTTPException(status_code=404, detail="映射不存在")

    # 保存为规则
    rule = await service.save_as_rule(mapping, current_user.id)

    return SaveAsRuleResponse(
        rule_id=rule.id,
        source_field=mapping.source_field,
        target_field=mapping.standard_field,
        message=f"规则已保存：'{mapping.source_field}' -> '{mapping.standard_field}'"
    )


# ===== 规则管理 API =====

@router.get("/rules/list", response_model=List[CompanyRuleResponse])
async def list_rules(
    rule_type: Optional[str] = Query(None, description="规则类型"),
    company_id: int = Depends(get_current_company),
    current_user: User = Depends(AuthService.get_current_user),
    service: MappingService = Depends(get_mapping_service),
):
    """获取企业的规则列表"""
    rules = await service.get_company_rules(company_id, rule_type)
    return [CompanyRuleResponse.model_validate(r) for r in rules]


@router.patch("/rules/{rule_id}/status", response_model=CompanyRuleResponse)
async def update_rule_status(
    rule_id: int,
    request: UpdateRuleStatusRequest,
    company_id: int = Depends(get_current_company),
    current_user: User = Depends(AuthService.get_current_user),
    service: MappingService = Depends(get_mapping_service),
):
    """更新规则状态（启用/停用）"""
    rule = await service.update_rule_status(rule_id, request.status)
    if not rule:
        raise HTTPException(status_code=404, detail="规则不存在")

    if rule.company_id != company_id:
        raise HTTPException(status_code=403, detail="无权操作此规则")

    return CompanyRuleResponse.model_validate(rule)


@router.delete("/rules/{rule_id}")
async def delete_rule(
    rule_id: int,
    company_id: int = Depends(get_current_company),
    current_user: User = Depends(AuthService.get_current_user),
    service: MappingService = Depends(get_mapping_service),
):
    """删除规则"""
    from app.models.company_rule import CompanyRule

    rule = await service.db.get(CompanyRule, rule_id)
    if not rule:
        raise HTTPException(status_code=404, detail="规则不存在")

    if rule.company_id != company_id:
        raise HTTPException(status_code=403, detail="无权操作此规则")

    success = await service.delete_rule(rule_id)
    if not success:
        raise HTTPException(status_code=500, detail="删除失败")

    return {"message": "规则已删除"}