package controllers

import (
	"context"
	"errors"
	"strings"

	"git.golem15.com/golem15/sm-journal-plugin/classes"
	"git.golem15.com/golem15/sm-journal-plugin/models"
	"git.golem15.com/golem15/summercms/modules/backpack"
	"git.golem15.com/golem15/summercms/modules/cabana"
	"git.golem15.com/golem15/summercms/modules/pact"
)

const (
	// CategoriesControllerID is the cabana controller id of the Categories screen.
	CategoriesControllerID = "golem15.journal.categories"
	// PermissionAccessCategories is Categories::$requiredPermissions.
	PermissionAccessCategories = "golem15.journal.access_categories"
)

type categoriesAdminController struct {
	app func() *backpack.App
}

func (categoriesAdminController) ID() string { return CategoriesControllerID }

func (categoriesAdminController) ModelName() string { return `Golem15\Journal\Models\Category` }

func (categoriesAdminController) ConfigDir() string { return "controllers/categories" }

func (categoriesAdminController) RequiredPermissions() []string {
	return []string{PermissionAccessCategories}
}

func (categoriesAdminController) NewRecord() any { return &models.Category{} }

func (categoriesAdminController) AdminFieldRelations() []cabana.FieldRelationContract {
	return []cabana.FieldRelationContract{{
		Field:       "parent",
		Kind:        "belongsTo",
		NewRelated:  func() any { return &models.Category{} },
		ForeignKey:  "parent_id",
		LabelColumn: "name",
	}}
}

func (categoriesAdminController) FormBeforeCreate(ctx context.Context, model any) error {
	cat, ok := model.(*models.Category)
	if !ok || cat == nil {
		return errors.New("categories admin: form model is not a category")
	}
	return prepareCategoryWrite(cat)
}

func (categoriesAdminController) FormBeforeUpdate(ctx context.Context, model any) error {
	cat, ok := model.(*models.Category)
	if !ok || cat == nil {
		return errors.New("categories admin: form model is not a category")
	}
	return prepareCategoryWrite(cat)
}

// FormAfterCreate purges the host site's page caches once the save
// transaction commits (G-16.2-2, D-19).
func (c categoriesAdminController) FormAfterCreate(ctx context.Context, model any) error {
	return c.purgeAfterCommit(ctx, model)
}

// FormAfterUpdate purges the host site's page caches once the save
// transaction commits (G-16.2-2, D-19).
func (c categoriesAdminController) FormAfterUpdate(ctx context.Context, model any) error {
	return c.purgeAfterCommit(ctx, model)
}

// FormAfterDelete purges the host site's page caches once the delete
// commits.
func (c categoriesAdminController) FormAfterDelete(ctx context.Context, model any) error {
	return c.purgeAfterCommit(ctx, model)
}

func (c categoriesAdminController) purgeAfterCommit(ctx context.Context, model any) error {
	cat, ok := model.(*models.Category)
	if !ok || cat == nil {
		return errors.New("categories admin: form model is not a category")
	}
	purger, tx := siteCachePurger(ctx, c.app)
	classes.PurgeSiteCacheAfterCommit(ctx, tx, purger, "category", cat.Slug)
	return nil
}

// prepareCategoryWrite stores blank category content (white space only) as
// NULL and accepts any other content it receives. Since Phase 16.2 the
// content field is the blogeditor type, whose Decode already stored the HTML
// policy's output (classes.SanitizeHTMLReport) and told the administrator
// what it removed, so an admin save is never refused because of markup
// (D-10 amended, see the bluemonday decision note). Rows written by SQL or
// by the import commands do not pass through here and are not sanitized by
// it.
func prepareCategoryWrite(cat *models.Category) error {
	if cat.Content == nil {
		return nil
	}
	if strings.TrimSpace(*cat.Content) == "" {
		cat.Content = nil
	}
	return nil
}

var (
	_ pact.AdminController         = categoriesAdminController{}
	_ pact.AdminPermissioned       = categoriesAdminController{}
	_ pact.AdminRecordSource       = categoriesAdminController{}
	_ pact.FormBeforeCreate        = categoriesAdminController{}
	_ pact.FormBeforeUpdate        = categoriesAdminController{}
	_ pact.FormAfterCreate         = categoriesAdminController{}
	_ pact.FormAfterUpdate         = categoriesAdminController{}
	_ pact.FormAfterDelete         = categoriesAdminController{}
	_ cabana.FieldRelationProvider = categoriesAdminController{}
)