from __future__ import annotations

from typing import Annotated

from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.orm import Session

from app.api.deps import CurrentUserContext, get_current_user, get_db
from app.schemas.common import ErrorResponse
from app.schemas.reimbursement import (
    ExpenseClaimActionResponse,
    ExpenseClaimItemUpdate,
    ExpenseClaimRead,
    ReimbursementCreate,
    ReimbursementRead,
)
from app.services.expense_claims import ExpenseClaimService
from app.services.reimbursement import ReimbursementService

router = APIRouter()
DbSession = Annotated[Session, Depends(get_db)]
CurrentUser = Annotated[CurrentUserContext, Depends(get_current_user)]


@router.get(
    "",
    response_model=list[ReimbursementRead],
    summary="查询报销申请列表",
    description="返回当前系统中的报销申请列表。",
)
def list_reimbursements(db: DbSession) -> list[ReimbursementRead]:
    return ReimbursementService(db).list_reimbursements()


@router.post(
    "",
    response_model=ReimbursementRead,
    status_code=status.HTTP_201_CREATED,
    summary="创建报销申请",
    description="创建一条新的报销申请记录，初始状态为 `draft`。",
)
def create_reimbursement(payload: ReimbursementCreate, db: DbSession) -> ReimbursementRead:
    return ReimbursementService(db).create_reimbursement(payload)


@router.get(
    "/claims",
    response_model=list[ExpenseClaimRead],
    summary="查询个人报销单列表",
    description="返回当前登录用户可见的真实个人报销单据列表。",
)
def list_expense_claims(db: DbSession, current_user: CurrentUser) -> list[ExpenseClaimRead]:
    return ExpenseClaimService(db).list_claims(current_user)


@router.get(
    "/claims/{claim_id}",
    response_model=ExpenseClaimRead,
    summary="读取个人报销单详情",
    description="根据报销单主键读取真实报销详情与费用明细。",
    responses={
        status.HTTP_404_NOT_FOUND: {
            "model": ErrorResponse,
            "description": "报销单不存在。",
        }
    },
)
def get_expense_claim(claim_id: str, db: DbSession, current_user: CurrentUser) -> ExpenseClaimRead:
    claim = ExpenseClaimService(db).get_claim(claim_id, current_user)
    if claim is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Claim not found")
    return claim


@router.patch(
    "/claims/{claim_id}/items/{item_id}",
    response_model=ExpenseClaimRead,
    summary="更新草稿费用明细",
    description="更新草稿报销单中的单条费用明细。",
    responses={
        status.HTTP_404_NOT_FOUND: {
            "model": ErrorResponse,
            "description": "报销单或费用明细不存在。",
        },
        status.HTTP_400_BAD_REQUEST: {
            "model": ErrorResponse,
            "description": "草稿状态校验失败或字段校验失败。",
        },
    },
)
def update_expense_claim_item(
    claim_id: str,
    item_id: str,
    payload: ExpenseClaimItemUpdate,
    db: DbSession,
    current_user: CurrentUser,
) -> ExpenseClaimRead:
    service = ExpenseClaimService(db)
    try:
        claim = service.update_claim_item(
            claim_id=claim_id,
            item_id=item_id,
            payload=payload,
            current_user=current_user,
        )
    except LookupError as error:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(error)) from error
    except ValueError as error:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(error)) from error

    if claim is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Claim not found")
    return claim


@router.post(
    "/claims/{claim_id}/submit",
    response_model=ExpenseClaimRead,
    summary="提交个人报销草稿",
    description="校验草稿信息完整性后，将报销单提交到审批流程。",
    responses={
        status.HTTP_404_NOT_FOUND: {
            "model": ErrorResponse,
            "description": "报销单不存在。",
        },
        status.HTTP_400_BAD_REQUEST: {
            "model": ErrorResponse,
            "description": "草稿信息不完整或状态不允许提交。",
        },
    },
)
def submit_expense_claim(claim_id: str, db: DbSession, current_user: CurrentUser) -> ExpenseClaimRead:
    service = ExpenseClaimService(db)
    try:
        claim = service.submit_claim(claim_id, current_user)
    except ValueError as error:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(error)) from error

    if claim is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Claim not found")
    return claim


@router.delete(
    "/claims/{claim_id}",
    response_model=ExpenseClaimActionResponse,
    summary="删除个人报销草稿",
    description="删除当前登录用户可见的草稿报销单。",
    responses={
        status.HTTP_404_NOT_FOUND: {
            "model": ErrorResponse,
            "description": "报销单不存在。",
        },
        status.HTTP_400_BAD_REQUEST: {
            "model": ErrorResponse,
            "description": "仅草稿状态允许删除。",
        },
    },
)
def delete_expense_claim(claim_id: str, db: DbSession, current_user: CurrentUser) -> ExpenseClaimActionResponse:
    service = ExpenseClaimService(db)
    try:
        claim = service.delete_claim(claim_id, current_user)
    except ValueError as error:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(error)) from error

    if claim is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Claim not found")

    return ExpenseClaimActionResponse(
        message=f"{claim.claim_no} 草稿已删除。",
        claim_id=claim.id,
        status="deleted",
    )


@router.get(
    "/{request_id}",
    response_model=ReimbursementRead,
    summary="读取报销申请详情",
    description="根据报销申请主键读取单据详情。",
    responses={
        status.HTTP_404_NOT_FOUND: {
            "model": ErrorResponse,
            "description": "报销申请不存在。",
        }
    },
)
def get_reimbursement(request_id: str, db: DbSession) -> ReimbursementRead:
    request = ReimbursementService(db).get_reimbursement(request_id)
    if request is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Request not found")
    return request