package label

import (
	"context"
	"fmt"

	"queryorchestration/internal/database/repository"
	"queryorchestration/internal/serviceconfig"

	"github.com/google/uuid"
)

// Service provides label management operations
type Service struct {
	cfg serviceconfig.ConfigProvider
}

// New creates a new label service instance
func New(cfg serviceconfig.ConfigProvider) *Service {
	return &Service{
		cfg: cfg,
	}
}

// ApplyLabel applies a label to a document with timestamp tracking
// Can be called multiple times for the same document/label to track re-application history
func (s *Service) ApplyLabel(ctx context.Context, documentID uuid.UUID, label string, appliedBy string) (*repository.Documentlabel, error) {
	if label == "" {
		return nil, fmt.Errorf("label cannot be empty")
	}

	if appliedBy == "" {
		return nil, fmt.Errorf("appliedBy cannot be empty")
	}

	result, err := s.cfg.GetDBQueries().ApplyLabel(ctx, &repository.ApplyLabelParams{
		Documentid: documentID,
		Label:      label,
		Appliedby:  appliedBy,
	})
	if err != nil {
		return nil, fmt.Errorf("failed to apply label: %w", err)
	}

	return result, nil
}

// GetDocumentLabels retrieves all label applications for a document
// Returns labels ordered by most recent application first
func (s *Service) GetDocumentLabels(ctx context.Context, documentID uuid.UUID) ([]*repository.Documentlabel, error) {
	labels, err := s.cfg.GetDBQueries().GetDocumentLabels(ctx, documentID)
	if err != nil {
		return nil, fmt.Errorf("failed to get document labels: %w", err)
	}

	return labels, nil
}

// GetMostRecentLabel retrieves the most recent application of a specific label for a document
func (s *Service) GetMostRecentLabel(ctx context.Context, documentID uuid.UUID, label string) (*repository.Documentlabel, error) {
	result, err := s.cfg.GetDBQueries().GetMostRecentLabel(ctx, &repository.GetMostRecentLabelParams{
		Documentid: documentID,
		Label:      label,
	})
	if err != nil {
		return nil, fmt.Errorf("label not found: %w", err)
	}

	return result, nil
}

// GetDocumentsByLabel retrieves all documents with a specific label for a client
func (s *Service) GetDocumentsByLabel(ctx context.Context, clientID string, label string) ([]*repository.Document, error) {
	documents, err := s.cfg.GetDBQueries().GetDocumentsByLabel(ctx, &repository.GetDocumentsByLabelParams{
		Clientid: clientID,
		Label:    label,
	})
	if err != nil {
		return nil, fmt.Errorf("failed to get documents by label: %w", err)
	}

	return documents, nil
}

// GetDocumentsByLabelAndFolder retrieves all documents with a specific label in a specific folder
func (s *Service) GetDocumentsByLabelAndFolder(ctx context.Context, folderID uuid.UUID, label string) ([]*repository.Document, error) {
	documents, err := s.cfg.GetDBQueries().GetDocumentsByLabelAndFolder(ctx, &repository.GetDocumentsByLabelAndFolderParams{
		Folderid: &folderID,
		Label:    label,
	})
	if err != nil {
		return nil, fmt.Errorf("failed to get documents by label and folder: %w", err)
	}

	return documents, nil
}

// GetAllLabels retrieves all available labels from the lookup table
func (s *Service) GetAllLabels(ctx context.Context) ([]*repository.Label, error) {
	labels, err := s.cfg.GetDBQueries().GetAllLabels(ctx)
	if err != nil {
		return nil, fmt.Errorf("failed to get all labels: %w", err)
	}

	return labels, nil
}

// CreateLabel creates a new label in the lookup table
func (s *Service) CreateLabel(ctx context.Context, label string, description string) (*repository.Label, error) {
	if label == "" {
		return nil, fmt.Errorf("label cannot be empty")
	}

	if description == "" {
		return nil, fmt.Errorf("description cannot be empty")
	}

	result, err := s.cfg.GetDBQueries().CreateLabel(ctx, &repository.CreateLabelParams{
		Label:       label,
		Description: description,
	})
	if err != nil {
		return nil, fmt.Errorf("failed to create label: %w", err)
	}

	return result, nil
}

// GetDocumentLabelHistory retrieves label application history for a client with pagination
func (s *Service) GetDocumentLabelHistory(ctx context.Context, clientID string, limit int32, offset int32) ([]*repository.GetDocumentLabelHistoryRow, error) {
	if limit <= 0 {
		return nil, fmt.Errorf("limit must be greater than 0")
	}

	if offset < 0 {
		return nil, fmt.Errorf("offset cannot be negative")
	}

	history, err := s.cfg.GetDBQueries().GetDocumentLabelHistory(ctx, &repository.GetDocumentLabelHistoryParams{
		Clientid: clientID,
		Limit:    int64(limit),
		Offset:   int64(offset),
	})
	if err != nil {
		return nil, fmt.Errorf("failed to get label history: %w", err)
	}

	return history, nil
}