package automation

import (
	"context"
	"fmt"

	applogger "github.com/gochat/gochat/pkg/logger"
)

// MacroService provides CRUD + execution for macros.
// Reference: Chatwoot Macros::ExecutionService — same action handler pattern as AutomationRule,
// but user-originated (supports 'self' assign). stamps user info.
type MacroService struct {
	db DBProvider
}

// NewMacroService creates a new MacroService.
func NewMacroService(db DBProvider) *MacroService {
	return &MacroService{db: db}
}

// GetByID retrieves a macro by ID.
func (s *MacroService) GetByID(ctx context.Context, id uint) (*Macro, error) {
	var macro Macro
	if err := s.db.DB().WithContext(ctx).First(&macro, id).Error; err != nil {
		return nil, err
	}
	return &macro, nil
}

// ListByAccount retrieves all macros for an account, respecting visibility.
// Personal macros are only visible to their creator; global macros are visible to all.
func (s *MacroService) ListByAccount(ctx context.Context, accountID uint, userID uint) ([]Macro, error) {
	var macros []Macro
	query := s.db.DB().WithContext(ctx).
		Where("account_id = ?", accountID)

	// Filter by visibility: show global macros + personal macros owned by this user
	query = query.Where("visibility = ? OR (visibility = ? AND created_by_id = ?)",
		MacroVisibilityGlobal, MacroVisibilityPersonal, userID)

	if err := query.Order("name ASC").Find(&macros).Error; err != nil {
		return nil, err
	}
	return macros, nil
}

// Create creates a new macro.
func (s *MacroService) Create(ctx context.Context, macro *Macro) error {
	// Use Select to force all fields including zero-value bool Active=false.
	// Without Select, GORM skips zero-value fields and uses column defaults.
	// Callers should explicitly set Active=true when creating new macros.
	return s.db.DB().WithContext(ctx).Select(
		"AccountID", "Name", "Actions", "Visibility", "Active",
		"CreatedByID", "UpdatedByID",
	).Create(macro).Error
}

// Update updates an existing macro.
func (s *MacroService) Update(ctx context.Context, macro *Macro) error {
	return s.db.DB().WithContext(ctx).Save(macro).Error
}

// Delete deletes a macro by ID.
func (s *MacroService) Delete(ctx context.Context, id uint) error {
	return s.db.DB().WithContext(ctx).Delete(&Macro{}, id).Error
}

// Clone creates a copy of a macro with "(copy)" appended to the name.
// Reference: Chatwoot Macro clone — duplicates actions, resets ID, stamps creator.
func (s *MacroService) Clone(ctx context.Context, id uint) (*Macro, error) {
	original, err := s.GetByID(ctx, id)
	if err != nil {
		return nil, fmt.Errorf("failed to load macro %d for clone: %w", id, err)
	}

	cloned := &Macro{
		AccountID:  original.AccountID,
		Name:       original.Name + " (copy)",
		Actions:    original.Actions,
		Visibility: original.Visibility,
		Active:     original.Active,
		CreatedByID: original.CreatedByID,
		UpdatedByID: original.UpdatedByID,
	}

	if err := s.Create(ctx, cloned); err != nil {
		return nil, fmt.Errorf("failed to create cloned macro: %w", err)
	}
	return cloned, nil
}

// ToggleActive flips the active state of a macro.
func (s *MacroService) ToggleActive(ctx context.Context, id uint, active bool) error {
	return s.db.DB().WithContext(ctx).
		Model(&Macro{}).
		Where("id = ?", id).
		Update("active", active).Error
}

// Execute runs a macro's actions on a conversation.
// Reference: Chatwoot Macros::ExecutionService stamps user info (executed_by)
// and supports 'self' assignment (assign to the user running the macro).
// Template variables in action params (e.g. {{contact.name}}) are resolved
// by ActionService before execution — the macro layer injects _source_user_id
// for 'self' assignment support and delegates execution to ActionService.
func (s *MacroService) Execute(ctx context.Context, accountID uint, conversationID uint, macroID uint, userID uint) error {
	macro, err := s.GetByID(ctx, macroID)
	if err != nil {
		return fmt.Errorf("failed to load macro %d: %w", macroID, err)
	}

	applogger.L().Infof("executing macro %d (%s) on conversation %d by user %d", macro.ID, macro.Name, conversationID, userID)

	actionSvc := NewActionService(s.db)

	for _, action := range macro.Actions {
		// Inject _source_user_id for "self" assignment support
		params := action.ActionParams
		if params == nil {
			params = map[string]interface{}{}
		}
		params["_source_user_id"] = userID

		resolvedAction := Action{
			ActionName:   action.ActionName,
			ActionParams: params,
		}

		// ActionService.Execute resolves template variables internally
		// ({{contact.name}}, {{conversation.status}}, etc.) before running the action.
		if err := actionSvc.Execute(ctx, accountID, conversationID, resolvedAction, ActionSourceMacro, userID); err != nil {
			applogger.L().Errorf("macro action %s failed for macro %d on conversation %d: %v", action.ActionName, macroID, conversationID, err)
			// Continue executing remaining actions (Chatwoot pattern)
		}
	}

	// Stamp execution record for audit trail
	// Reference: Chatwoot stamps user info (executed_by_id)
	return s.recordExecution(ctx, macroID, conversationID, userID)
}

// recordExecution logs that a macro was executed on a conversation by a user.
func (s *MacroService) recordExecution(ctx context.Context, macroID, conversationID, userID uint) error {
	record := &MacroExecution{
		MacroID:        macroID,
		ConversationID: conversationID,
		ExecutedByID:   userID,
	}
	return s.db.DB().WithContext(ctx).Create(record).Error
}

// MacroExecution records a macro execution event for audit trail.
type MacroExecution struct {
	ID             uint   `gorm:"primaryKey;autoIncrement" json:"id"`
	MacroID        uint   `gorm:"index;not null" json:"macro_id"`
	ConversationID uint   `gorm:"index;not null" json:"conversation_id"`
	ExecutedByID   uint   `gorm:"index;not null" json:"executed_by_id"`
}

func (MacroExecution) TableName() string { return "macro_executions" }