from typing import Optional

from fastapi import APIRouter, Depends, Form, Header, HTTPException, Response
from sqlalchemy.orm import Session

from app.core.response import success_response
from app.db import get_db_session
from app.services.audit_log_service import AuditLogService
from app.services.auth_service import AuthService
from app.services.template_service import TemplateService

router = APIRouter(prefix="/templates", tags=["templates"])
ROUTE_PERMISSION_SCOPE = "template_management"
ROUTE_PERMISSION_ACTIONS = {
    "list": "templates:list",
    "create": "templates:create",
    "seed_defaults": "templates:seed_defaults",
    "update": "templates:update",
    "delete": "templates:delete",
}


def get_template_service(db: Session = Depends(get_db_session)) -> TemplateService:
    return TemplateService(db)


def get_audit_log_service(db: Session = Depends(get_db_session)) -> AuditLogService:
    return AuditLogService(db)


def require_current_user(
    authorization: Optional[str] = Header(default=None),
    db: Session = Depends(get_db_session),
):
    return AuthService(db).require_current_user(authorization)


@router.get("")
def list_templates(
    page: int = 1,
    page_size: int = 20,
    contract_type: Optional[str] = None,
    template_service: TemplateService = Depends(get_template_service),
    current_user: dict = Depends(require_current_user),
):
    return success_response(template_service.list_templates(current_user, page, page_size, contract_type))


@router.post("")
def create_template(
    name: str = Form(...),
    contract_type: Optional[str] = Form(default=None),
    description: Optional[str] = Form(default=None),
    content: str = Form(...),
    variables_json: Optional[str] = Form(default=None),
    enabled: bool = Form(default=True),
    template_service: TemplateService = Depends(get_template_service),
    audit_log_service: AuditLogService = Depends(get_audit_log_service),
    current_user: dict = Depends(require_current_user),
):
    result = template_service.create_template(current_user, name, contract_type, description, content, variables_json, enabled)
    audit_log_service.record_event(
        tenant_id=current_user.get("tenant_id"),
        user_id=current_user.get("id"),
        action="create_template",
        resource_type="template",
        resource_id=result["id"],
        detail_json={
            "name": result["name"],
            "contract_type": result["contract_type"],
            "enabled": result["enabled"],
            "variable_count": len(result.get("variables", [])),
        },
    )
    return success_response(result)


@router.post("/seed-defaults")
def seed_default_templates(
    template_service: TemplateService = Depends(get_template_service),
    audit_log_service: AuditLogService = Depends(get_audit_log_service),
    current_user: dict = Depends(require_current_user),
):
    result = template_service.seed_default_templates(current_user)
    audit_log_service.record_event(
        tenant_id=current_user.get("tenant_id"),
        user_id=current_user.get("id"),
        action="seed_default_templates",
        resource_type="template",
        resource_id=None,
        detail_json={
            "created_count": result["created_count"],
            "existing_count": result["existing_count"],
            "total": result["total"],
            "template_names": result.get("template_names", []),
        },
    )
    return success_response(result)


@router.put("/{template_id}")
def update_template(
    template_id: str,
    name: str = Form(...),
    contract_type: Optional[str] = Form(default=None),
    description: Optional[str] = Form(default=None),
    content: str = Form(...),
    variables_json: Optional[str] = Form(default=None),
    enabled: bool = Form(default=True),
    template_service: TemplateService = Depends(get_template_service),
    audit_log_service: AuditLogService = Depends(get_audit_log_service),
    current_user: dict = Depends(require_current_user),
):
    result = template_service.update_template(current_user, template_id, name, contract_type, description, content, variables_json, enabled)
    audit_log_service.record_event(
        tenant_id=current_user.get("tenant_id"),
        user_id=current_user.get("id"),
        action="update_template",
        resource_type="template",
        resource_id=result["id"],
        detail_json={
            "name": result["name"],
            "contract_type": result["contract_type"],
            "enabled": result["enabled"],
            "variable_count": len(result.get("variables", [])),
        },
    )
    return success_response(result)


@router.delete("/{template_id}")
def delete_template(
    template_id: str,
    template_service: TemplateService = Depends(get_template_service),
    audit_log_service: AuditLogService = Depends(get_audit_log_service),
    current_user: dict = Depends(require_current_user),
):
    deleted_template = template_service.delete_template(current_user, template_id)
    audit_log_service.record_event(
        tenant_id=current_user.get("tenant_id"),
        user_id=current_user.get("id"),
        action="delete_template",
        resource_type="template",
        resource_id=template_id,
        detail_json={
            "name": deleted_template["name"],
            "contract_type": deleted_template["contract_type"],
            "enabled": deleted_template["enabled"],
            "variable_count": len(deleted_template.get("variables", [])),
        },
    )
    return Response(status_code=204)