package controllers

import (
	"context"
	"errors"
	"strings"

	"git.golem15.com/golem15/sm-golem-plugin/models"
	"git.golem15.com/golem15/summercms/modules/cabana"
	"git.golem15.com/golem15/summercms/modules/pact"
)

// PermissionAccessSettings guards the AI models screen.
const PermissionAccessSettings = "golem15.golem.access_settings"

// ModelsAdminController is the AI models list and form
// (golem15.golem.models). The API key is write-only: the form shows it
// redacted, and an update that sends it back empty or redacted keeps the
// stored key, unless the same update changes the adapter or base URL.
type ModelsAdminController struct{}

var (
	_ pact.AdminController   = ModelsAdminController{}
	_ pact.AdminPermissioned = ModelsAdminController{}
	_ pact.AdminRecordSource = ModelsAdminController{}
	_ pact.FormBeforeCreate  = ModelsAdminController{}
	_ pact.FormBeforeUpdate  = ModelsAdminController{}
)

// ID is golem15.golem.models.
func (ModelsAdminController) ID() string { return "golem15.golem.models" }

// ModelName is the model's WinterCMS class name.
func (ModelsAdminController) ModelName() string { return `Golem15\Golem\Models\AiModel` }

// ConfigDir holds config_list.yaml and config_form.yaml.
func (ModelsAdminController) ConfigDir() string { return "controllers/aimodels" }

// RequiredPermissions is golem15.golem.access_settings.
func (ModelsAdminController) RequiredPermissions() []string {
	return []string{PermissionAccessSettings}
}

// NewRecord returns an empty AI model.
func (ModelsAdminController) NewRecord() any { return &models.AiModel{} }

// redacted is how lagoon.Encrypted serializes, so how the form shows the
// stored key.
const redacted = "[redacted]"

func keyMissing(m *models.AiModel) bool {
	k := m.APIKey.Reveal()
	return k == "" || k == redacted
}

// FormBeforeCreate requires an API key.
func (ModelsAdminController) FormBeforeCreate(_ context.Context, model any) error {
	m, ok := model.(*models.AiModel)
	if !ok {
		return errors.New("golem: unexpected admin record")
	}
	if keyMissing(m) {
		return &cabana.ValidationError{Details: map[string]any{"api_key": []string{"The api key field is required."}}}
	}
	return nil
}

// baseURLOf is a model's base URL with nil and blank alike.
func baseURLOf(m *models.AiModel) string {
	if m.BaseURL == nil {
		return ""
	}
	return strings.TrimSpace(*m.BaseURL)
}

// FormBeforeUpdate keeps the stored key when the form sent it back empty
// or redacted. A kept key never follows a changed endpoint: when the
// adapter or base URL differs from the stored one, the key must be entered
// again, so an operator who cannot read the key cannot redirect it to a
// host they control either.
func (ModelsAdminController) FormBeforeUpdate(ctx context.Context, model any) error {
	m, ok := model.(*models.AiModel)
	if !ok {
		return errors.New("golem: unexpected admin record")
	}
	if !keyMissing(m) {
		return nil
	}
	tx, ok := cabana.TxFromContext(ctx)
	if !ok {
		return errors.New("golem: no transaction for the model update")
	}
	var stored models.AiModel
	if err := tx.Select("api_key", "adapter", "base_url").Where("id = ?", m.ID).Take(&stored).Error; err != nil {
		return err
	}
	if stored.Adapter != m.Adapter || baseURLOf(&stored) != baseURLOf(m) {
		return &cabana.ValidationError{Details: map[string]any{"api_key": []string{"Re-enter the API key when changing the adapter or base URL."}}}
	}
	m.APIKey = stored.APIKey
	if keyMissing(m) {
		return &cabana.ValidationError{Details: map[string]any{"api_key": []string{"The api key field is required."}}}
	}
	return nil
}