package checker

import (
	"context"
	"strconv"

	"github.com/samber/lo"
	"github.com/tidbcloud/tiinf/monitor/tilog"
	"go.uber.org/zap"
	"google.golang.org/grpc"

	"github.com/tidbcloud/tidb-management-service/tidb-mgmt-service/pkg/apimiddleware/bizerror"
	"github.com/tidbcloud/tidb-management-service/utilities/bizerr"
	"github.com/tidbcloud/tidb-management-service/utilities/grpc/metadata"
)

// StdProjectIdExtractor extracts project_id from requests that implement GetProjectId() directly.
func StdProjectIdExtractor(req any) (string, error) {
	type projectIdRequest interface{ GetProjectId() string }
	r, ok := req.(projectIdRequest)
	if !ok {
		return "", bizerr.New(bizerr.ErrCodeParams, "invalid request: req=%v", req)
	}
	return r.GetProjectId(), nil
}

// NewProjectIdChecker creates a permission checker that validates the requesting user
// has access to the project. The extractProjectId function extracts the project ID string
// from the request.
func NewProjectIdChecker(extractProjectId func(req any) (string, error)) CheckFunc {
	return func(
		ctx context.Context,
		_ *CheckContext,
		req any,
		info *grpc.UnaryServerInfo,
	) (context.Context, any, error) {
		reqMeta, err := metadata.ExtractRequestMeta(ctx)
		if err != nil {
			tilog.Error(ctx, "failed to extract request metadata", zap.Error(err))
			return ctx, req, bizerror.NewInternal(err, "failed to extract request metadata")
		}

		projectIdStr, err := extractProjectId(req)
		if err != nil {
			return ctx, req, err
		}

		if projectIdStr != "" {
			projectId, err := strconv.ParseUint(projectIdStr, 10, 64)
			if err != nil {
				return ctx, req, bizerr.WrapErrorWithCode(err, bizerr.ErrCodeParams, "invalid project id %s", projectIdStr)
			}

			if err := reqMeta.CheckProjectIDsPermission(projectId); err != nil {
				return ctx, req, bizerr.WrapErrorWithCode(err, bizerr.ErrCodePermission, bizerr.ErrMsgResourceNoPermission)
			}

			reqMeta.DefaultProjectID = projectId
		}

		reqMeta.IsCheckPermission = lo.ToPtr(true)
		return metadata.AppendToIncomingMeta(ctx, reqMeta), req, nil
	}
}