package service

import (
	"context"
	"fmt"

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

// AgentBotInboxService implements business logic for bot-inbox bindings.
// Reference: Chatwoot app/controllers/api/v1/accounts/agent_bot_inboxes_controller.rb
type AgentBotInboxService struct {
	repo    *repository.AgentBotInboxRepo
	botRepo *repository.AgentBotRepo
}

// NewAgentBotInboxService creates a new AgentBotInbox service.
func NewAgentBotInboxService(repo *repository.AgentBotInboxRepo, botRepo *repository.AgentBotRepo) *AgentBotInboxService {
	return &AgentBotInboxService{repo: repo, botRepo: botRepo}
}

// BindBotToInboxRequest is the DTO for binding a bot to an inbox.
type BindBotToInboxRequest struct {
	AgentBotID uint `json:"agent_bot_id" validate:"required"`
	InboxID    uint `json:"inbox_id" validate:"required"`
}

// UpdateBindingStatusRequest is the DTO for toggling a binding's active/inactive status.
type UpdateBindingStatusRequest struct {
	Status int `json:"status" validate:"required,oneof=0 1"`
}

// Bind creates a new bot-inbox binding with status=active.
// accountID is auto-filled from the inbox's account_id.
func (s *AgentBotInboxService) Bind(ctx context.Context, accountID uint, req BindBotToInboxRequest) (*model.AgentBotInbox, error) {
	// Verify the bot exists
	bot, err := s.botRepo.FindByID(ctx, req.AgentBotID)
	if err != nil {
		applogger.L().Errorf("Bind bot to inbox: bot %d not found: %v", req.AgentBotID, err)
		return nil, fmt.Errorf("agent bot not found: %w", err)
	}

	// Check for duplicate binding
	existing, err := s.repo.FindByAgentBotAndInbox(ctx, req.AgentBotID, req.InboxID)
	if err == nil && existing != nil {
		applogger.L().Errorf("Bind bot to inbox: duplicate binding bot=%d inbox=%d", req.AgentBotID, req.InboxID)
		return nil, fmt.Errorf("bot already bound to this inbox")
	}

	abi := &model.AgentBotInbox{
		AgentBotID: req.AgentBotID,
		InboxID:    req.InboxID,
		AccountID:  bot.AccountID, // auto-fill from bot's account; may be nil for platform bots
		Status:     model.AgentBotInboxActive,
	}

	if err := s.repo.Create(ctx, abi); err != nil {
		applogger.L().Errorf("Bind bot to inbox: create failed: %v", err)
		return nil, err
	}

	applogger.L().Infof("Bound agent bot %d to inbox %d (binding %d)", req.AgentBotID, req.InboxID, abi.ID)
	return abi, nil
}

// Unbind removes a bot-inbox binding by ID.
func (s *AgentBotInboxService) Unbind(ctx context.Context, id uint) error {
	if err := s.repo.Delete(ctx, id); err != nil {
		applogger.L().Errorf("Unbind bot-inbox binding %d: %v", id, err)
		return err
	}
	applogger.L().Infof("Unbound bot-inbox binding %d", id)
	return nil
}

// UpdateStatus toggles the active/inactive status of a bot-inbox binding.
func (s *AgentBotInboxService) UpdateStatus(ctx context.Context, id uint, req UpdateBindingStatusRequest) (*model.AgentBotInbox, error) {
	abi, err := s.repo.FindByID(ctx, id)
	if err != nil {
		applogger.L().Errorf("Update binding status %d: not found: %v", id, err)
		return nil, fmt.Errorf("binding not found: %w", err)
	}

	abi.Status = model.AgentBotInboxStatus(req.Status)

	if err := s.repo.Update(ctx, abi); err != nil {
		applogger.L().Errorf("Update binding status %d: save failed: %v", id, err)
		return nil, err
	}

	applogger.L().Infof("Updated bot-inbox binding %d status to %d", id, req.Status)
	return abi, nil
}

// ListByInbox retrieves all bot-inbox bindings for a given inbox.
func (s *AgentBotInboxService) ListByInbox(ctx context.Context, inboxID uint) ([]model.AgentBotInbox, error) {
	abis, err := s.repo.FindByInboxID(ctx, inboxID)
	if err != nil {
		applogger.L().Errorf("List bot-inbox bindings for inbox %d: %v", inboxID, err)
		return nil, err
	}
	return abis, nil
}

// ListActiveByInbox retrieves only active bot-inbox bindings for a given inbox.
func (s *AgentBotInboxService) ListActiveByInbox(ctx context.Context, inboxID uint) ([]model.AgentBotInbox, error) {
	abis, err := s.repo.FindActiveByInboxID(ctx, inboxID)
	if err != nil {
		applogger.L().Errorf("List active bot-inbox bindings for inbox %d: %v", inboxID, err)
		return nil, err
	}
	return abis, nil
}

// ListByBot retrieves all bot-inbox bindings for a given agent bot.
func (s *AgentBotInboxService) ListByBot(ctx context.Context, agentBotID uint) ([]model.AgentBotInbox, error) {
	abis, err := s.repo.FindByAgentBotID(ctx, agentBotID)
	if err != nil {
		applogger.L().Errorf("List bot-inbox bindings for bot %d: %v", agentBotID, err)
		return nil, err
	}
	return abis, nil
}