package repository

import (
	"context"
	"fmt"
	"net/http"
	"slices"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/validation/field"

	provisioning "github.com/grafana/grafana/apps/provisioning/pkg/apis/provisioning/v0alpha1"
)

// RepositoryValidator interface for validating repositories against existing ones
type RepositoryValidator interface {
	VerifyAgainstExistingRepositories(ctx context.Context, cfg *provisioning.Repository) *field.Error
}

func TestRepository(ctx context.Context, repo Repository) (*provisioning.TestResults, error) {
	return TestRepositoryWithValidator(ctx, repo, nil)
}

func TestRepositoryWithValidator(ctx context.Context, repo Repository, validator RepositoryValidator) (*provisioning.TestResults, error) {
	errors := ValidateRepository(repo)
	if len(errors) > 0 {
		rsp := &provisioning.TestResults{
			Code:    http.StatusUnprocessableEntity, // Invalid
			Success: false,
			Errors:  make([]provisioning.ErrorDetails, len(errors)),
		}
		for i, err := range errors {
			rsp.Errors[i] = provisioning.ErrorDetails{
				Type:   metav1.CauseType(err.Type),
				Field:  err.Field,
				Detail: err.Detail,
			}
		}
		return rsp, nil
	}

	rsp, err := repo.Test(ctx)
	if err != nil {
		return nil, err
	}

	if rsp.Success && validator != nil {
		cfg := repo.Config()
		if validationErr := validator.VerifyAgainstExistingRepositories(ctx, cfg); validationErr != nil {
			rsp = &provisioning.TestResults{
				Success: false,
				Code:    http.StatusUnprocessableEntity,
				Errors: []provisioning.ErrorDetails{{
					Type:   metav1.CauseType(validationErr.Type),
					Field:  validationErr.Field,
					Detail: validationErr.Detail,
				}},
			}
		}
	}

	return rsp, nil
}

func ValidateRepository(repo Repository) field.ErrorList {
	list := repo.Validate()
	cfg := repo.Config()

	if cfg.Spec.Title == "" {
		list = append(list, field.Required(field.NewPath("spec", "title"), "a repository title must be given"))
	}

	if cfg.Spec.Sync.Enabled && cfg.Spec.Sync.Target == "" {
		list = append(list, field.Required(field.NewPath("spec", "sync", "target"),
			"The target type is required when sync is enabled"))
	}

	// Reserved names (for now)
	reserved := []string{"classic", "sql", "SQL", "plugins", "legacy", "new", "job", "github", "s3", "gcs", "file", "new", "create", "update", "delete"}
	if slices.Contains(reserved, cfg.Name) {
		list = append(list, field.Invalid(field.NewPath("metadata", "name"), cfg.Name, "Name is reserved, choose a different identifier"))
	}

	if cfg.Spec.Type != provisioning.LocalRepositoryType && cfg.Spec.Local != nil {
		list = append(list, field.Invalid(field.NewPath("spec", "local"),
			cfg.Spec.GitHub, "Local config only valid when type is local"))
	}

	if cfg.Spec.Type != provisioning.GitHubRepositoryType && cfg.Spec.GitHub != nil {
		list = append(list, field.Invalid(field.NewPath("spec", "github"),
			cfg.Spec.GitHub, "Github config only valid when type is github"))
	}

	if cfg.Spec.Type != provisioning.GitRepositoryType && cfg.Spec.Git != nil {
		list = append(list, field.Invalid(field.NewPath("spec", "git"),
			cfg.Spec.Git, "Git config only valid when type is git"))
	}

	for _, w := range cfg.Spec.Workflows {
		switch w {
		case provisioning.WriteWorkflow: // valid; no fall thru
		case provisioning.BranchWorkflow:
			if !cfg.Spec.Type.IsGit() {
				list = append(list, field.Invalid(field.NewPath("spec", "workflow"), w, "branch is only supported on git repositories"))
			}
		default:
			list = append(list, field.Invalid(field.NewPath("spec", "workflow"), w, "invalid workflow"))
		}
	}

	if slices.Contains(cfg.Finalizers, RemoveOrphanResourcesFinalizer) &&
		slices.Contains(cfg.Finalizers, ReleaseOrphanResourcesFinalizer) {
		list = append(list,
			field.Invalid(
				field.NewPath("medatada", "finalizers"),
				cfg.Finalizers,
				"cannot have both remove and release orphan resources finalizers",
			),
		)
	}

	for _, f := range cfg.Finalizers {
		if !slices.Contains(SupportedFinalizers, f) {
			list = append(list,
				field.Invalid(
					field.NewPath("medatada", "finalizers"),
					cfg.Finalizers,
					fmt.Sprintf("unknown finalizer: %s", f),
				),
			)
		}
	}

	return list
}

func FromFieldError(err *field.Error) *provisioning.TestResults {
	return &provisioning.TestResults{
		Code:    http.StatusBadRequest,
		Success: false,
		Errors: []provisioning.ErrorDetails{{
			Type:   metav1.CauseType(err.Type),
			Field:  err.Field,
			Detail: err.Detail,
		}},
	}
}