package automation

import (
	"context"
	"fmt"
	"time"

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

// ActionSource identifies who triggered the action execution.
// Reference: Chatwoot stamps automation_rule_id for rule actions, user info for macro actions
type ActionSource string

const (
	ActionSourceAutomation ActionSource = "automation_rule"
	ActionSourceMacro      ActionSource = "macro"
	ActionSourceUser       ActionSource = "user"
	ActionSourceBotRule    ActionSource = "bot_rule" // AgentBot automation rule execution
)

// ActionService provides the shared base for executing automation and macro actions.
// Reference: Chatwoot ActionService — 14 handlers shared between AutomationRules and Macros.
// AutomationRules::ActionService stamps automation_rule_id. Macros::ExecutionService stamps user info.
type ActionService struct {
	db DBProvider
}

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

// Execute runs a single action on a conversation.
// source and sourceID provide the audit trail (automation_rule_id or macro_id or user_id).
// Template variables in action params (e.g. {{contact.name}}) are resolved before execution.
func (s *ActionService) Execute(ctx context.Context, accountID uint, conversationID uint, action Action, source ActionSource, sourceID uint) error {
	applogger.L().Infof("executing action %s (source=%s, sourceID=%d) on conversation %d", action.ActionName, source, sourceID, conversationID)

	// Resolve template variables in action params before executing the action.
	// This allows actions like send_message to use {{contact.name}}, {{conversation.status}}, etc.
	resolvedAction, err := s.resolveTemplateVars(ctx, conversationID, action)
	if err != nil {
		applogger.L().Warnf("template variable resolution failed for action %s on conversation %d: %v", action.ActionName, conversationID, err)
		// Continue with unresolved params — template resolution failure should not block action execution
		resolvedAction = action
	}

	switch resolvedAction.ActionName {
	case "send_message":
		return s.handleSendMessage(ctx, accountID, conversationID, resolvedAction, source, sourceID)
	case "add_label":
		return s.handleAddLabel(ctx, accountID, conversationID, resolvedAction)
	case "remove_label":
		return s.handleRemoveLabel(ctx, accountID, conversationID, resolvedAction)
	case "assign_agent":
		return s.handleAssignAgent(ctx, accountID, conversationID, resolvedAction)
	case "assign_team":
		return s.handleAssignTeam(ctx, accountID, conversationID, resolvedAction)
	case "remove_assigned_agent":
		return s.handleRemoveAssignedAgent(ctx, accountID, conversationID)
	case "remove_assigned_team":
		return s.handleRemoveAssignedTeam(ctx, accountID, conversationID)
	case "send_webhook_event":
		return s.handleSendWebhookEvent(ctx, accountID, conversationID, resolvedAction)
	case "mute_conversation":
		return s.handleMuteConversation(ctx, accountID, conversationID)
	case "change_status":
		return s.handleChangeStatus(ctx, accountID, conversationID, resolvedAction)
	case "resolve_conversation":
		return s.handleChangeStatus(ctx, accountID, conversationID, Action{
			ActionName: "change_status",
			ActionParams: map[string]interface{}{"status": "resolved"},
		})
	case "open_conversation":
		return s.handleChangeStatus(ctx, accountID, conversationID, Action{
			ActionName: "change_status",
			ActionParams: map[string]interface{}{"status": "open"},
		})
	case "pending_conversation":
		return s.handleChangeStatus(ctx, accountID, conversationID, Action{
			ActionName: "change_status",
			ActionParams: map[string]interface{}{"status": "pending"},
		})
	case "snooze_conversation":
		return s.handleChangeStatus(ctx, accountID, conversationID, Action{
			ActionName: "change_status",
			ActionParams: map[string]interface{}{"status": "snoozed"},
		})
	case "change_priority":
		return s.handleChangePriority(ctx, accountID, conversationID, resolvedAction)
	case "send_email_transcript":
		return s.handleSendEmailTranscript(ctx, accountID, conversationID, resolvedAction)
	case "send_attachment":
		return s.handleSendAttachment(ctx, accountID, conversationID, resolvedAction)
	case "add_private_note":
		return s.handleAddPrivateNote(ctx, accountID, conversationID, resolvedAction, source, sourceID)
	default:
		return fmt.Errorf("unsupported action: %s", resolvedAction.ActionName)
	}
}

// resolveTemplateVars builds a TemplateContext for the given conversation and resolves
// all {{variable}} placeholders in the action's params.
func (s *ActionService) resolveTemplateVars(ctx context.Context, conversationID uint, action Action) (Action, error) {
	builder := NewTemplateContextBuilder(s.db)
	tctx, err := builder.Build(ctx, conversationID)
	if err != nil {
		return action, err
	}

	resolvedParams := ResolveActionParams(action.ActionParams, tctx)
	return Action{
		ActionName:  action.ActionName,
		ActionParams: resolvedParams,
	}, nil
}

// ===========================
// Action Handlers
// ===========================

// handleSendMessage sends a message to the conversation.
// Reference: Chatwoot send_message action — creates an outgoing message in the conversation
func (s *ActionService) handleSendMessage(ctx context.Context, accountID, conversationID uint, action Action, source ActionSource, sourceID uint) error {
	content, _ := action.ActionParams["content"].(string)
	if content == "" {
		return fmt.Errorf("send_message action requires 'content' param")
	}

	// Determine sender: for automation, use the bot/user who owns the rule
	senderID := sourceID
	senderType := "bot"
	if source == ActionSourceMacro || source == ActionSourceUser {
		senderType = "agent"
	}

	msg := &model.Message{
		ConversationID: conversationID,
		AccountID:      accountID,
		SenderID:       &senderID,
		SenderType:     senderType,
		Content:        content,
		ContentType:    "text",
		MessageType:    "outgoing",
		Private:        false,
	}

	return s.db.DB().WithContext(ctx).Create(msg).Error
}

// handleAddLabel adds a label to the conversation.
// Reference: Chatwoot add_label action — adds tag/label to conversation
func (s *ActionService) handleAddLabel(ctx context.Context, accountID, conversationID uint, action Action) error {
	labels := extractStringSlice(action.ActionParams, "labels")
	if len(labels) == 0 {
		// Single label param
		label, _ := action.ActionParams["label"].(string)
		if label == "" {
			return fmt.Errorf("add_label action requires 'label' or 'labels' param")
		}
		labels = []string{label}
	}

	// Create conversation_label records for each label
	for _, label := range labels {
		cl := &ConversationLabel{
			ConversationID: conversationID,
			Label:          label,
		}
		if err := s.db.DB().WithContext(ctx).Where(cl).FirstOrCreate(cl).Error; err != nil {
			applogger.L().Errorf("failed to add label '%s' to conversation %d: %v", label, conversationID, err)
			// Continue with remaining labels
		}
	}
	return nil
}

// handleRemoveLabel removes a label from the conversation.
// Reference: Chatwoot remove_label action
func (s *ActionService) handleRemoveLabel(ctx context.Context, accountID, conversationID uint, action Action) error {
	labels := extractStringSlice(action.ActionParams, "labels")
	if len(labels) == 0 {
		label, _ := action.ActionParams["label"].(string)
		if label == "" {
			return fmt.Errorf("remove_label action requires 'label' or 'labels' param")
		}
		labels = []string{label}
	}

	for _, label := range labels {
		if err := s.db.DB().WithContext(ctx).
			Where("conversation_id = ? AND label = ?", conversationID, label).
			Delete(&ConversationLabel{}).Error; err != nil {
			applogger.L().Errorf("failed to remove label '%s' from conversation %d: %v", label, conversationID, err)
		}
	}
	return nil
}

// handleAssignAgent assigns an agent to the conversation.
// Reference: Chatwoot assign_agent action — sets assignee_id on conversation
func (s *ActionService) handleAssignAgent(ctx context.Context, accountID, conversationID uint, action Action) error {
	assigneeID := extractUintParam(action.ActionParams, "assignee_id")

	// Support "self" assignment for macros — assigns the user executing the macro
	assigneeIDStr, _ := action.ActionParams["assignee_id"].(string)
	if assigneeIDStr == "self" {
		// For macros, sourceID is the user executing the macro
		assigneeID = sourceID(action)
	}

	return s.db.DB().WithContext(ctx).
		Model(&model.Conversation{}).
		Where("id = ? AND account_id = ?", conversationID, accountID).
		Update("assignee_id", assigneeID).Error
}

// handleAssignTeam assigns a team to the conversation.
// Reference: Chatwoot assign_team action — sets team_id on conversation
func (s *ActionService) handleAssignTeam(ctx context.Context, accountID, conversationID uint, action Action) error {
	teamID := extractUintParam(action.ActionParams, "team_id")
	return s.db.DB().WithContext(ctx).
		Model(&model.Conversation{}).
		Where("id = ? AND account_id = ?", conversationID, accountID).
		Update("team_id", teamID).Error
}

// handleRemoveAssignedAgent unassigns the agent from the conversation.
// Reference: Chatwoot remove_assigned_agent action — sets assignee_id to NULL
func (s *ActionService) handleRemoveAssignedAgent(ctx context.Context, accountID, conversationID uint) error {
	return s.db.DB().WithContext(ctx).
		Model(&model.Conversation{}).
		Where("id = ? AND account_id = ?", conversationID, accountID).
		Update("assignee_id", nil).Error
}

// handleRemoveAssignedTeam unassigns the team from the conversation.
// Reference: Chatwoot remove_assigned_team action — sets team_id to NULL
func (s *ActionService) handleRemoveAssignedTeam(ctx context.Context, accountID, conversationID uint) error {
	return s.db.DB().WithContext(ctx).
		Model(&model.Conversation{}).
		Where("id = ? AND account_id = ?", conversationID, accountID).
		Update("team_id", nil).Error
}

// handleSendWebhookEvent sends a webhook event for the conversation.
// Reference: Chatwoot send_webhook_event action — POSTs to configured webhook URL
func (s *ActionService) handleSendWebhookEvent(ctx context.Context, accountID, conversationID uint, action Action) error {
	url, _ := action.ActionParams["url"].(string)
	if url == "" {
		return fmt.Errorf("send_webhook_event action requires 'url' param")
	}

	// TODO: Implement webhook delivery in P10 async task processing
	// For now, log the webhook intent
	applogger.L().Infof("webhook event to %s for conversation %d (TODO: async delivery)", url, conversationID)
	return nil
}

// handleMuteConversation mutes notifications for the conversation.
// Reference: Chatwoot mute_conversation action — marks conversation as muted
func (s *ActionService) handleMuteConversation(ctx context.Context, accountID, conversationID uint) error {
	muted := &ConversationMute{
		ConversationID: conversationID,
		AccountID:      accountID,
	}
	return s.db.DB().WithContext(ctx).Where(muted).FirstOrCreate(muted).Error
}

// handleChangeStatus changes the conversation status.
// Reference: Chatwoot change_status action — updates conversation status
func (s *ActionService) handleChangeStatus(ctx context.Context, accountID, conversationID uint, action Action) error {
	status, _ := action.ActionParams["status"].(string)
	if status == "" {
		return fmt.Errorf("change_status action requires 'status' param")
	}

	// Validate status against known values
	validStatuses := map[string]bool{
		"open":     true,
		"resolved": true,
		"pending":  true,
		"snoozed":  true,
	}
	if !validStatuses[status] {
		return fmt.Errorf("invalid status '%s'", status)
	}

	return s.db.DB().WithContext(ctx).
		Model(&model.Conversation{}).
		Where("id = ? AND account_id = ?", conversationID, accountID).
		Update("status", status).Error
}

// handleChangePriority changes the conversation priority.
// Reference: Chatwoot change_priority action
func (s *ActionService) handleChangePriority(ctx context.Context, accountID, conversationID uint, action Action) error {
	priority, _ := action.ActionParams["priority"].(string)
	if priority == "" {
		return fmt.Errorf("change_priority action requires 'priority' param")
	}

	validPriorities := map[string]bool{
		"urgent": true,
		"high":   true,
		"medium": true,
		"low":    true,
	}
	if !validPriorities[priority] {
		return fmt.Errorf("invalid priority '%s'", priority)
	}

	// Note: the conversation model doesn't currently have a priority field
	// This will be added in a future migration. For now, we store it in metadata.
	applogger.L().Infof("change_priority to '%s' for conversation %d", priority, conversationID)

	// Update priority field if it exists on the conversations table
	return s.db.DB().WithContext(ctx).
		Model(&model.Conversation{}).
		Where("id = ? AND account_id = ?", conversationID, accountID).
		Update("priority", priority).Error
}

// handleSendEmailTranscript sends an email transcript of the conversation.
// Reference: Chatwoot send_email_transcript action
func (s *ActionService) handleSendEmailTranscript(ctx context.Context, accountID, conversationID uint, action Action) error {
	email, _ := action.ActionParams["email"].(string)
	if email == "" {
		return fmt.Errorf("send_email_transcript action requires 'email' param")
	}

	// TODO: Implement email transcript delivery — requires email service integration
	applogger.L().Infof("email transcript to %s for conversation %d (TODO: email service)", email, conversationID)
	return nil
}

// handleSendAttachment sends an attachment message to the conversation.
// Reference: Chatwoot send_attachment action
func (s *ActionService) handleSendAttachment(ctx context.Context, accountID, conversationID uint, action Action) error {
	attachmentURL, _ := action.ActionParams["attachment_url"].(string)
	if attachmentURL == "" {
		return fmt.Errorf("send_attachment action requires 'attachment_url' param")
	}

	// Create a message with attachment content type
	senderID := uint(0) // Bot sender
	msg := &model.Message{
		ConversationID: conversationID,
		AccountID:      accountID,
		SenderID:       &senderID,
		SenderType:     "bot",
		Content:        attachmentURL,
		ContentType:    "file",
		MessageType:    "outgoing",
		Private:        false,
	}

	return s.db.DB().WithContext(ctx).Create(msg).Error
}

// handleAddPrivateNote adds a private note (internal comment) to the conversation.
// Reference: Chatwoot add_private_note action
func (s *ActionService) handleAddPrivateNote(ctx context.Context, accountID, conversationID uint, action Action, source ActionSource, sourceID uint) error {
	content, _ := action.ActionParams["content"].(string)
	if content == "" {
		return fmt.Errorf("add_private_note action requires 'content' param")
	}

	msg := &model.Message{
		ConversationID: conversationID,
		AccountID:      accountID,
		SenderID:       &sourceID,
		SenderType:     "agent",
		Content:        content,
		ContentType:    "text",
		MessageType:    "outgoing",
		Private:        true,
	}

	return s.db.DB().WithContext(ctx).Create(msg).Error
}

// ===========================
// Helper types for action side-effects
// ===========================

// ConversationLabel represents a label attached to a conversation.
// Reference: Chatwoot's Tagging / Label system
type ConversationLabel struct {
	ID             uint   `gorm:"primaryKey;autoIncrement" json:"id"`
	ConversationID uint   `gorm:"index;not null" json:"conversation_id"`
	Label          string `gorm:"size:255;index;not null" json:"label"`
}

func (ConversationLabel) TableName() string { return "conversation_labels" }

// ConversationMute represents a muted conversation.
// Reference: Chatwoot ConversationMute model
type ConversationMute struct {
	ID             uint      `gorm:"primaryKey;autoIncrement" json:"id"`
	ConversationID uint      `gorm:"index;not null" json:"conversation_id"`
	AccountID      uint      `gorm:"index;not null" json:"account_id"`
	CreatedAt      time.Time `gorm:"autoCreateTime" json:"created_at"`
}

func (ConversationMute) TableName() string { return "conversation_mutes" }

// ===========================
// Helpers
// ===========================

// extractStringSlice extracts a string slice from action params, handling both
// []string and []interface{} (from JSON deserialization) formats.
func extractStringSlice(params map[string]interface{}, key string) []string {
	raw, ok := params[key]
	if !ok {
		return nil
	}

	switch v := raw.(type) {
	case []string:
		return v
	case []interface{}:
		result := make([]string, len(v))
		for i, item := range v {
			result[i] = fmt.Sprintf("%v", item)
		}
		return result
	default:
		return nil
	}
}

// extractUintParam extracts a uint parameter from action params.
// Handles both numeric and string representations.
func extractUintParam(params map[string]interface{}, key string) uint {
	raw, ok := params[key]
	if !ok {
		return 0
	}

	switch v := raw.(type) {
	case uint:
		return v
	case int:
		return uint(v)
	case float64:
		return uint(v)
	case string:
		// "self" is handled separately in assign_agent
		return 0
	default:
		return 0
	}
}

// sourceID extracts the source ID from action params for "self" assignment.
func sourceID(action Action) uint {
	id, ok := action.ActionParams["_source_user_id"]
	if !ok {
		return 0
	}
	switch v := id.(type) {
	case uint:
		return v
	case int:
		return uint(v)
	case float64:
		return uint(v)
	default:
		return 0
	}
}