package service

import (
	"fmt"
	"io"
	"log/slog"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"git.vakhrushev.me/av/transcriber/internal/contract"
	"git.vakhrushev.me/av/transcriber/internal/entity"
	"git.vakhrushev.me/av/transcriber/internal/metrics"
	"github.com/google/uuid"
)

const (
	defaultAudioExt = "audio"
)

type TranscribeService struct {
	jobRepo     contract.TranscriptJobRepository
	fileRepo    contract.FileRepository
	metaviewer  contract.AudioMetaViewer
	converter   contract.AudioFileConverter
	recognizer  contract.AudioRecognizer
	storagePath string
	logger      *slog.Logger
}

func NewTranscribeService(
	jobRepo contract.TranscriptJobRepository,
	fileRepo contract.FileRepository,
	metaviewer contract.AudioMetaViewer,
	converter contract.AudioFileConverter,
	recognizer contract.AudioRecognizer,
	storagePath string,
	logger *slog.Logger,
) *TranscribeService {
	return &TranscribeService{
		jobRepo:     jobRepo,
		fileRepo:    fileRepo,
		metaviewer:  metaviewer,
		converter:   converter,
		recognizer:  recognizer,
		storagePath: storagePath,
		logger:      logger,
	}
}

func (s *TranscribeService) CreateTranscribeJob(file io.Reader, fileName string) (*entity.TranscribeJob, error) {
	// Генерируем UUID для файла
	fileId := uuid.NewString()

	// Определяем расширение файла
	ext := filepath.Ext(fileName)
	if ext == "" {
		ext = fmt.Sprintf(".%s", defaultAudioExt) // fallback если расширение не определено
	}

	// Создаем путь для сохранения файла
	storageFileName := fmt.Sprintf("%s%s", fileId, ext)
	storageFilePath := filepath.Join(s.storagePath, storageFileName)

	s.logger.Info("Creating transcribe job",
		"file_id", fileId,
		"file_name", fileName,
		"storage_path", storageFilePath)

	// Создаем файл на диске
	dst, err := os.Create(storageFilePath)
	if err != nil {
		s.logger.Error("Failed to create file", "error", err, "path", storageFilePath)
		return nil, err
	}
	defer dst.Close()

	// Копируем содержимое загруженного файла
	size, err := io.Copy(dst, file)
	if err != nil {
		s.logger.Error("Failed to copy file content", "error", err)
		return nil, err
	}

	if err := dst.Close(); err != nil {
		s.logger.Error("Failed to close file", "error", err)
		return nil, err
	}

	info, err := s.metaviewer.GetInfo(storageFilePath)
	if err != nil {
		s.logger.Error("Failed to get file info", "error", err, "path", storageFilePath)
		return nil, err
	}

	s.logger.Info("File uploaded successfully",
		"file_id", fileId,
		"size", size,
		"duration_seconds", info.Seconds)

	metrics.InputFileDurationHistogram.WithLabelValues().Observe(float64(info.Seconds))
	metrics.InputFileSizeHistogram.WithLabelValues(ext).Observe(float64(size))

	// Создаем запись в таблице files
	fileRecord := &entity.File{
		Id:        fileId,
		Storage:   entity.StorageLocal,
		FileName:  storageFileName,
		Size:      size,
		CreatedAt: time.Now(),
	}

	if err := s.fileRepo.Create(fileRecord); err != nil {
		// Удаляем файл если не удалось создать запись в БД
		os.Remove(storageFilePath)
		s.logger.Error("Failed to create file record", "error", err, "file_id", fileId)
		return nil, err
	}

	jobId := uuid.NewString()
	now := time.Now()

	// Создаем запись в таблице transcribe_jobs
	job := &entity.TranscribeJob{
		Id:        jobId,
		State:     entity.StateCreated,
		FileID:    &fileId,
		IsError:   false,
		CreatedAt: now,
		UpdatedAt: now,
	}

	if err := s.jobRepo.Create(job); err != nil {
		s.logger.Error("Failed to create job record", "error", err, "job_id", jobId)
		return nil, err
	}

	s.logger.Info("Transcribe job created successfully", "job_id", jobId, "file_id", fileId)
	return job, nil
}

func (s *TranscribeService) FindAndRunConversionJob() error {
	acquisitionId := uuid.NewString()
	rottingTime := time.Now().Add(-1 * time.Hour)

	job, err := s.jobRepo.FindAndAcquire(entity.StateCreated, acquisitionId, rottingTime)
	if err != nil {
		if _, ok := err.(*contract.JobNotFoundError); ok {
			return &contract.NoopJobError{State: entity.StateCreated}
		}
		s.logger.Error("Failed to find and acquire conversion job", "error", err)
		return err
	}

	s.logger.Info("Starting conversion job", "job_id", job.Id, "acquisition_id", acquisitionId)

	srcFile, err := s.fileRepo.GetByID(*job.FileID)
	if err != nil {
		s.logger.Error("Failed to get source file", "error", err, "file_id", *job.FileID)
		return err
	}

	srcFilePath := filepath.Join(s.storagePath, srcFile.FileName)

	destFileId := uuid.NewString()
	destFileName := fmt.Sprintf("%s%s", destFileId, ".ogg")
	destFilePath := filepath.Join(s.storagePath, destFileName)

	// Получаем расширение исходного файла для метрики
	srcExt := strings.TrimPrefix(filepath.Ext(srcFile.FileName), ".")
	if srcExt == "" {
		srcExt = defaultAudioExt
	}

	s.logger.Info("Converting file",
		"job_id", job.Id,
		"src_path", srcFilePath,
		"dest_path", destFilePath,
		"src_format", srcExt)

	// Измеряем время конвертации
	startTime := time.Now()
	err = s.converter.Convert(srcFilePath, destFilePath)
	conversionDuration := time.Since(startTime)

	// Записываем метрику времени конвертации
	metrics.ConversionDurationHistogram.
		WithLabelValues(srcExt, "ogg", strconv.FormatBool(err != nil)).
		Observe(conversionDuration.Seconds())

	if err != nil {
		s.logger.Error("File conversion failed",
			"error", err,
			"job_id", job.Id,
			"duration", conversionDuration)
		return err
	}

	stat, err := os.Stat(destFilePath)
	if err != nil {
		s.logger.Error("Failed to stat converted file", "error", err, "path", destFilePath)
		return err
	}

	s.logger.Info("File conversion completed",
		"job_id", job.Id,
		"duration", conversionDuration,
		"output_size", stat.Size())

	// Записываем метрику размера выходного файла
	metrics.OutputFileSizeHistogram.WithLabelValues("ogg").Observe(float64(stat.Size()))

	// Создаем запись в таблице files
	destFileRecord := &entity.File{
		Id:        destFileId,
		Storage:   entity.StorageLocal,
		FileName:  destFileName,
		Size:      stat.Size(),
		CreatedAt: time.Now(),
	}

	job.FileID = &destFileId
	job.MoveToState(entity.StateConverted)

	err = s.fileRepo.Create(destFileRecord)
	if err != nil {
		s.logger.Error("Failed to create converted file record", "error", err, "file_id", destFileId)
		return err
	}

	err = s.jobRepo.Save(job)
	if err != nil {
		s.logger.Error("Failed to save job", "error", err, "job_id", job.Id)
		return err
	}

	s.logger.Info("Conversion job completed successfully", "job_id", job.Id)
	return nil
}

func (s *TranscribeService) FindAndRunTranscribeJob() error {
	acquisitionId := uuid.NewString()
	rottingTime := time.Now().Add(-1 * time.Hour)

	jobRecord, err := s.jobRepo.FindAndAcquire(entity.StateConverted, acquisitionId, rottingTime)
	if err != nil {
		if _, ok := err.(*contract.JobNotFoundError); ok {
			return &contract.NoopJobError{State: entity.StateConverted}
		}
		s.logger.Error("Failed to find and acquire transcribe job", "error", err)
		return err
	}

	s.logger.Info("Starting transcribe job", "job_id", jobRecord.Id, "acquisition_id", acquisitionId)

	fileRecord, err := s.fileRepo.GetByID(*jobRecord.FileID)
	if err != nil {
		s.logger.Error("Failed to get file record", "error", err, "file_id", *jobRecord.FileID)
		return err
	}

	filePath := filepath.Join(s.storagePath, fileRecord.FileName)

	file, err := os.Open(filePath)
	if err != nil {
		s.logger.Error("Failed to open file", "error", err, "path", filePath)
		return err
	}
	defer file.Close()

	destFileId := uuid.NewString()
	destFileRecord := fileRecord.CopyWithStorage(destFileId, entity.StorageS3)

	s.logger.Info("Starting recognition", "job_id", jobRecord.Id, "file_path", filePath)

	// Запускаем асинхронное распознавание
	operationID, err := s.recognizer.Recognize(file, destFileRecord.FileName)
	if err != nil {
		s.logger.Error("Failed to start recognition", "error", err, "job_id", jobRecord.Id)
		return err
	}

	s.logger.Info("Recognition started",
		"job_id", jobRecord.Id,
		"operation_id", operationID)

	// Обновляем задачу с ID операции распознавания
	jobRecord.FileID = &destFileId
	jobRecord.RecognitionOpID = &operationID
	delayTime := time.Now().Add(10 * time.Second)
	jobRecord.MoveToStateAndDelay(entity.StateTranscribe, &delayTime)

	err = s.fileRepo.Create(destFileRecord)
	if err != nil {
		s.logger.Error("Failed to create S3 file record", "error", err, "file_id", destFileId)
		return err
	}

	err = s.jobRepo.Save(jobRecord)
	if err != nil {
		s.logger.Error("Failed to save job", "error", err, "job_id", jobRecord.Id)
		return err
	}

	s.logger.Info("Transcribe job updated successfully", "job_id", jobRecord.Id)
	return nil
}

func (s *TranscribeService) FindAndRunTranscribeCheckJob() error {
	acquisitionId := uuid.NewString()
	rottingTime := time.Now().Add(-24 * time.Hour)

	job, err := s.jobRepo.FindAndAcquire(entity.StateTranscribe, acquisitionId, rottingTime)
	if err != nil {
		if _, ok := err.(*contract.JobNotFoundError); ok {
			return &contract.NoopJobError{State: entity.StateTranscribe}
		}
		s.logger.Error("Failed to find and acquire transcribe check job", "error", err)
		return fmt.Errorf("failed find and acquire job: %s, %w", entity.StateTranscribe, err)
	}

	if job.RecognitionOpID == nil {
		s.logger.Error("Recognition operation ID not found", "job_id", job.Id)
		return fmt.Errorf("recogniton opId not found for job: %s", job.Id)
	}

	opId := *job.RecognitionOpID

	// Проверяем статус операции
	s.logger.Info("Checking operation status", "job_id", job.Id, "operation_id", opId)
	recResult, err := s.recognizer.CheckRecognitionStatus(opId)
	if err != nil {
		s.logger.Error("Failed to check recognition status", "error", err, "operation_id", opId)
		return err
	}

	if recResult.IsInProgress() {
		// Операция еще не завершена, оставляем в статусе обработки
		s.logger.Info("Operation in progress", "job_id", job.Id, "operation_id", opId)
		delayTime := time.Now().Add(10 * time.Second)
		job.MoveToStateAndDelay(entity.StateTranscribe, &delayTime)
		err := s.jobRepo.Save(job)
		if err != nil {
			s.logger.Error("Failed to save job", "error", err, "job_id", job.Id)
			return err
		}
		return nil
	}

	if recResult.IsFailed() {
		errorText := recResult.GetError()
		s.logger.Error("Operation failed",
			"job_id", job.Id,
			"operation_id", opId,
			"error_message", errorText)
		job.Fail(errorText)
		err := s.jobRepo.Save(job)
		if err != nil {
			s.logger.Error("Failed to save failed job", "error", err, "job_id", job.Id)
			return err
		}
		return nil
	}

	// Операция завершена, получаем результат
	transcriptionText, err := s.recognizer.GetRecognitionText(opId)
	if err != nil {
		s.logger.Error("Failed to get recognition text", "error", err, "operation_id", opId)
		return err
	}

	s.logger.Info("Operation completed successfully",
		"job_id", job.Id,
		"operation_id", opId,
		"text_length", len(transcriptionText))

	// Обновляем задачу с результатом
	job.Done(transcriptionText)

	err = s.jobRepo.Save(job)
	if err != nil {
		s.logger.Error("Failed to save completed job", "error", err, "job_id", job.Id)
		return err
	}

	s.logger.Info("Transcribe check job completed successfully", "job_id", job.Id)
	return nil
}