from datetime import datetime
from typing import Annotated, TypeVar

from core_domain import ServiceHealth
from core_shared import try_build_redis_client
from fastapi import APIRouter, Depends, Header, HTTPException, Request
from sqlalchemy import text
from sqlalchemy.orm import Session

from app.application.services import AuthApplicationService
from app.db.session import get_db
from app.domain.repositories import (
    ApiKeyRepository,
    RoleAssignmentRepository,
    RolePermissionBindingRepository,
    RoleRepository,
    UserRepository,
)
from app.schemas.identity import (
    ApiKeyCreateData,
    ApiKeyCreateRequestDto,
    ApiKeyDto,
    ApiKeyRevokeRequest,
    ApiResponse,
    AuthMeData,
    BindingRemoveRequest,
    DeleteData,
    LoginData,
    LoginRequestDto,
    PageRequest,
    PageResult,
    PermissionCheckData,
    PermissionCheckRequestDto,
    RoleDto,
    RolePermissionBindingAddRequest,
    RolePermissionBindingDto,
    RolePermissionBindingListRequest,
    TokenVerifyData,
    TokenVerifyRequestDto,
    UserDto,
)

router = APIRouter()
DbSession = Annotated[Session, Depends(get_db)]
T = TypeVar("T")


def get_identity_application_service(request: Request, db: DbSession) -> AuthApplicationService:
    settings = request.app.state.settings
    return AuthApplicationService(
        user_repository=UserRepository(db),
        role_repository=RoleRepository(db),
        assignment_repository=RoleAssignmentRepository(db),
        permission_binding_repository=RolePermissionBindingRepository(db),
        api_key_repository=ApiKeyRepository(db),
        token_secret=settings.credential_encryption_key,
        redis_client=try_build_redis_client(settings.redis_url),
        permission_cache_ttl_seconds=settings.permission_cache_ttl_seconds)


IdentityServiceDep = Annotated[AuthApplicationService, Depends(get_identity_application_service)]
AuthorizationHeader = Annotated[str | None, Header(alias="Authorization")]


def ok(request: Request, data: T) -> ApiResponse[T]:
    return ApiResponse[T](
        data=data,
        requestId=request.headers.get("x-request-id", ""),
        serverTime=datetime.utcnow())


def get_bearer_token(authorization: str | None) -> str:
    if not authorization:
        raise HTTPException(status_code=401, detail="missing authorization header")
    scheme, _, token = authorization.partition(" ")
    if scheme.lower() != "bearer" or not token:
        raise HTTPException(status_code=401, detail="invalid authorization header")
    return token


@router.get("/health", response_model=ServiceHealth)
def health_check(db: DbSession) -> ServiceHealth:
    db.execute(text("SELECT 1"))
    return ServiceHealth(service="identity-service", status="ok", database="ok")


@router.post("/auth/login", response_model=ApiResponse[LoginData])
def login(
    request: Request,
    payload: LoginRequestDto,
    service: IdentityServiceDep) -> ApiResponse[LoginData]:
    result = service.login(username=payload.username, password=payload.password)
    if result is None:
        raise HTTPException(status_code=401, detail="invalid username or password")
    return ok(
        request,
        LoginData(
            accessToken=result.access_token,
            expiresTime=result.expires_time,
            user=UserDto.from_entity(result.user)))


@router.post("/auth/logout", response_model=ApiResponse[dict[str, bool]])
def logout(
    request: Request,
    service: IdentityServiceDep,
    authorization: AuthorizationHeader = None) -> ApiResponse[dict[str, bool]]:
    access_token = get_bearer_token(authorization) if authorization else None
    return ok(request, {"ok": service.logout(access_token=access_token)})


@router.post("/auth/tokens/verify", response_model=ApiResponse[TokenVerifyData])
def verify_token(
    request: Request,
    payload: TokenVerifyRequestDto,
    service: IdentityServiceDep) -> ApiResponse[TokenVerifyData]:
    result = service.verify_token(access_token=payload.accessToken)
    return ok(
        request,
        TokenVerifyData(
            active=result.active,
            userId=result.user_id,
            username=result.username,
            expiresTime=result.expires_time,
            reason=result.reason))


@router.post("/auth/me", response_model=ApiResponse[AuthMeData])
def me(
    request: Request,
    service: IdentityServiceDep,
    authorization: AuthorizationHeader = None) -> ApiResponse[AuthMeData]:
    token = get_bearer_token(authorization)
    verified = service.verify_token(access_token=token)
    if not verified.active or verified.user_id is None:
        raise HTTPException(status_code=401, detail=verified.reason or "invalid token")
    user = service.user_repository.get_by_id(user_id=verified.user_id)
    if user is None:
        raise HTTPException(status_code=401, detail="user not found")

    assignments = service.assignment_repository.list_by_user(user_id=user.id)
    roles = []
    permissions: set[str] = set()
    for assignment in assignments:
        role = service.role_repository.get_by_id(role_id=assignment.role_id)
        if role is None:
            continue
        bindings = service.permission_binding_repository.list_all_by_role(role_id=role.id)
        roles.append(RoleDto.from_entity(role, permission_binding_count=len(bindings)))
        permissions.update(binding.permission for binding in bindings)
    return ok(
        request,
        AuthMeData(
            user=UserDto.from_entity(user),
            roles=roles,
            permissions=sorted(permissions)))


@router.post("/users/list", response_model=ApiResponse[PageResult[UserDto]])
def list_users(
    request: Request,
    payload: PageRequest,
    service: IdentityServiceDep) -> ApiResponse[PageResult[UserDto]]:
    items, total = service.list_users_page(
        page=payload.page,
        page_size=payload.pageSize,
        keyword=payload.keyword)
    return ok(
        request,
        PageResult[UserDto].from_items(
            items=[UserDto.from_entity(item) for item in items],
            total=total,
            page=payload.page,
            page_size=payload.pageSize))


@router.post("/roles/list", response_model=ApiResponse[PageResult[RoleDto]])
def list_roles(
    request: Request,
    payload: PageRequest,
    service: IdentityServiceDep) -> ApiResponse[PageResult[RoleDto]]:
    items, total = service.list_roles_page(
        page=payload.page,
        page_size=payload.pageSize,
        keyword=payload.keyword)
    binding_repo = service.permission_binding_repository
    return ok(
        request,
        PageResult[RoleDto].from_items(
            items=[
                RoleDto.from_entity(
                    item,
                    permission_binding_count=len(binding_repo.list_all_by_role(role_id=item.id)))
                for item in items
            ],
            total=total,
            page=payload.page,
            page_size=payload.pageSize))


@router.post(
    "/rolePermissionBindings/list",
    response_model=ApiResponse[PageResult[RolePermissionBindingDto]])
def list_role_permission_bindings(
    request: Request,
    payload: RolePermissionBindingListRequest,
    service: IdentityServiceDep) -> ApiResponse[PageResult[RolePermissionBindingDto]]:
    items, total = service.list_role_permission_bindings(
        role_id=payload.roleId,
        page=payload.page,
        page_size=payload.pageSize)
    return ok(
        request,
        PageResult[RolePermissionBindingDto].from_items(
            items=[RolePermissionBindingDto.from_entity(item) for item in items],
            total=total,
            page=payload.page,
            page_size=payload.pageSize))


@router.post("/rolePermissionBindings/add", response_model=ApiResponse[RolePermissionBindingDto])
def add_role_permission_binding(
    request: Request,
    payload: RolePermissionBindingAddRequest,
    service: IdentityServiceDep) -> ApiResponse[RolePermissionBindingDto]:
    entity = service.add_role_permission_binding(
        role_id=payload.roleId,
        permission=payload.permission,
        scope_type=payload.scopeType,
        scope_id=payload.scopeId)
    return ok(request, RolePermissionBindingDto.from_entity(entity))


@router.post("/rolePermissionBindings/remove", response_model=ApiResponse[DeleteData])
def remove_role_permission_binding(
    request: Request,
    payload: BindingRemoveRequest,
    service: IdentityServiceDep) -> ApiResponse[DeleteData]:
    deleted = service.remove_role_permission_binding(binding_id=payload.bindingId)
    return ok(request, DeleteData(deleted=deleted, bindingId=payload.bindingId))


@router.post("/permissions/check", response_model=ApiResponse[PermissionCheckData])
def check_permission(
    request: Request,
    payload: PermissionCheckRequestDto,
    service: IdentityServiceDep) -> ApiResponse[PermissionCheckData]:
    result = service.check_permission(
        user_id=payload.userId,
        permission=payload.permission,
        scope_type=payload.scopeType,
        scope_id=payload.scopeId)
    return ok(
        request,
        PermissionCheckData(
            allowed=result.allowed,
            reason=result.reason,
            matchedRoleIds=result.matched_role_ids))


@router.post("/apiKeys/list", response_model=ApiResponse[PageResult[ApiKeyDto]])
def list_api_keys(
    request: Request,
    payload: PageRequest,
    service: IdentityServiceDep) -> ApiResponse[PageResult[ApiKeyDto]]:
    items, total = service.list_api_keys_page(
        page=payload.page,
        page_size=payload.pageSize,
        keyword=payload.keyword)
    return ok(
        request,
        PageResult[ApiKeyDto].from_items(
            items=[ApiKeyDto.from_entity(item) for item in items],
            total=total,
            page=payload.page,
            page_size=payload.pageSize))


@router.post("/apiKeys/create", response_model=ApiResponse[ApiKeyCreateData])
def create_api_key(
    request: Request,
    payload: ApiKeyCreateRequestDto,
    service: IdentityServiceDep) -> ApiResponse[ApiKeyCreateData]:
    entity, secret = service.create_api_key(
        name=payload.name,
        scopes=payload.scopes,
        expires_time=payload.expiresTime)
    return ok(
        request,
        ApiKeyCreateData(
            apiKey=ApiKeyDto.from_entity(entity),
            secret=secret))


@router.post("/apiKeys/revoke", response_model=ApiResponse[ApiKeyDto])
def revoke_api_key(
    request: Request,
    payload: ApiKeyRevokeRequest,
    service: IdentityServiceDep) -> ApiResponse[ApiKeyDto]:
    entity = service.revoke_api_key(api_key_id=payload.apiKeyId)
    if entity is None:
        raise HTTPException(status_code=404, detail=f"api key not found: {payload.apiKeyId}")
    return ok(request, ApiKeyDto.from_entity(entity))