package services

import (
	"database/sql"
	"fmt"
	"time"

	"github.com/rede5/gohorsejobs/backend/internal/dto"
	"github.com/rede5/gohorsejobs/backend/internal/models"
)

type VideoInterviewService struct {
	DB *sql.DB
}

func NewVideoInterviewService(db *sql.DB) *VideoInterviewService {
	return &VideoInterviewService{DB: db}
}

func (s *VideoInterviewService) CreateInterview(req dto.CreateVideoInterviewRequest, createdBy string) (*models.VideoInterview, error) {
	scheduledAt, err := time.Parse(time.RFC3339, req.ScheduledAt)
	if err != nil {
		return nil, fmt.Errorf("invalid scheduled_at format: %w", err)
	}

	if req.Timezone == "" {
		req.Timezone = "UTC"
	}

	if req.MeetingProvider == nil {
		provider := "custom"
		req.MeetingProvider = &provider
	}

	query := `
		INSERT INTO video_interviews (
			application_id, scheduled_at, duration_minutes, timezone,
			meeting_provider, notes, status, created_by, created_at, updated_at
		) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)
		RETURNING id, created_at, updated_at
	`

	interview := &models.VideoInterview{
		ApplicationID:   req.ApplicationID,
		ScheduledAt:     scheduledAt,
		DurationMinutes: req.DurationMinutes,
		Timezone:        req.Timezone,
		MeetingProvider: req.MeetingProvider,
		Notes:           req.Notes,
		Status:          "scheduled",
		CreatedBy:       &createdBy,
		CreatedAt:       time.Now(),
		UpdatedAt:       time.Now(),
	}

	err = s.DB.QueryRow(
		query,
		interview.ApplicationID, interview.ScheduledAt, interview.DurationMinutes, interview.Timezone,
		interview.MeetingProvider, interview.Notes, interview.Status, interview.CreatedBy,
		interview.CreatedAt, interview.UpdatedAt,
	).Scan(&interview.ID, &interview.CreatedAt, &interview.UpdatedAt)

	if err != nil {
		return nil, fmt.Errorf("failed to create interview: %w", err)
	}

	return interview, nil
}

func (s *VideoInterviewService) GetInterviewByID(id string) (*models.VideoInterview, error) {
	query := `
		SELECT id, application_id, scheduled_at, duration_minutes, timezone,
			   meeting_link, meeting_provider, meeting_id, meeting_password,
			   status, started_at, ended_at, notes, interviewer_feedback, 
			   candidate_feedback, rating, created_by, created_at, updated_at
		FROM video_interviews WHERE id = $1
	`

	interview := &models.VideoInterview{}
	err := s.DB.QueryRow(query, id).Scan(
		&interview.ID, &interview.ApplicationID, &interview.ScheduledAt, &interview.DurationMinutes, &interview.Timezone,
		&interview.MeetingLink, &interview.MeetingProvider, &interview.MeetingID, &interview.MeetingPassword,
		&interview.Status, &interview.StartedAt, &interview.EndedAt, &interview.Notes, &interview.InterviewerFeedback,
		&interview.CandidateFeedback, &interview.Rating, &interview.CreatedBy, &interview.CreatedAt, &interview.UpdatedAt,
	)

	if err != nil {
		return nil, err
	}

	return interview, nil
}

func (s *VideoInterviewService) GetInterviewsByApplication(applicationID string) ([]models.VideoInterview, error) {
	query := `
		SELECT id, application_id, scheduled_at, duration_minutes, timezone,
			   meeting_link, meeting_provider, meeting_id, meeting_password,
			   status, started_at, ended_at, notes, interviewer_feedback, 
			   candidate_feedback, rating, created_by, created_at, updated_at
		FROM video_interviews 
		WHERE application_id = $1
		ORDER BY scheduled_at DESC
	`

	rows, err := s.DB.Query(query, applicationID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var interviews []models.VideoInterview
	for rows.Next() {
		var interview models.VideoInterview
		err := rows.Scan(
			&interview.ID, &interview.ApplicationID, &interview.ScheduledAt, &interview.DurationMinutes, &interview.Timezone,
			&interview.MeetingLink, &interview.MeetingProvider, &interview.MeetingID, &interview.MeetingPassword,
			&interview.Status, &interview.StartedAt, &interview.EndedAt, &interview.Notes, &interview.InterviewerFeedback,
			&interview.CandidateFeedback, &interview.Rating, &interview.CreatedBy, &interview.CreatedAt, &interview.UpdatedAt,
		)
		if err != nil {
			return nil, err
		}
		interviews = append(interviews, interview)
	}

	return interviews, nil
}

func (s *VideoInterviewService) GetInterviewsByCompany(companyID string) ([]models.VideoInterviewWithDetails, error) {
	query := `
		SELECT 
			vi.id, vi.application_id, vi.scheduled_at, vi.duration_minutes, vi.timezone,
			vi.meeting_link, vi.meeting_provider, vi.meeting_id, vi.meeting_password,
			vi.status, vi.started_at, vi.ended_at, vi.notes, vi.interviewer_feedback, 
			vi.candidate_feedback, vi.rating, vi.created_by, vi.created_at, vi.updated_at,
			j.title as job_title, c.id as company_id, c.name as company_name,
			COALESCE(u.name, a.name) as candidate_name,
			COALESCE(u.email, a.email) as candidate_email
		FROM video_interviews vi
		JOIN applications a ON vi.application_id = a.id
		JOIN jobs j ON a.job_id = j.id
		JOIN companies c ON j.company_id = c.id
		LEFT JOIN users u ON a.user_id = u.id
		WHERE c.id = $1
		ORDER BY vi.scheduled_at DESC
	`

	rows, err := s.DB.Query(query, companyID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var interviews []models.VideoInterviewWithDetails
	for rows.Next() {
		var interview models.VideoInterviewWithDetails
		err := rows.Scan(
			&interview.ID, &interview.ApplicationID, &interview.ScheduledAt, &interview.DurationMinutes, &interview.Timezone,
			&interview.MeetingLink, &interview.MeetingProvider, &interview.MeetingID, &interview.MeetingPassword,
			&interview.Status, &interview.StartedAt, &interview.EndedAt, &interview.Notes, &interview.InterviewerFeedback,
			&interview.CandidateFeedback, &interview.Rating, &interview.CreatedBy, &interview.CreatedAt, &interview.UpdatedAt,
			&interview.JobTitle, &interview.CompanyID, &interview.CompanyName,
			&interview.CandidateName, &interview.CandidateEmail,
		)
		if err != nil {
			return nil, err
		}
		interviews = append(interviews, interview)
	}

	return interviews, nil
}

func (s *VideoInterviewService) UpdateInterview(id string, req dto.UpdateVideoInterviewRequest) (*models.VideoInterview, error) {
	interview, err := s.GetInterviewByID(id)
	if err != nil {
		return nil, err
	}

	if req.ScheduledAt != nil {
		scheduledAt, err := time.Parse(time.RFC3339, *req.ScheduledAt)
		if err != nil {
			return nil, fmt.Errorf("invalid scheduled_at format: %w", err)
		}
		interview.ScheduledAt = scheduledAt
	}

	if req.DurationMinutes != nil {
		interview.DurationMinutes = *req.DurationMinutes
	}

	if req.Timezone != nil {
		interview.Timezone = *req.Timezone
	}

	if req.MeetingLink != nil {
		interview.MeetingLink = req.MeetingLink
	}

	if req.MeetingProvider != nil {
		interview.MeetingProvider = req.MeetingProvider
	}

	if req.MeetingID != nil {
		interview.MeetingID = req.MeetingID
	}

	if req.MeetingPassword != nil {
		interview.MeetingPassword = req.MeetingPassword
	}

	if req.Status != nil {
		interview.Status = *req.Status

		if *req.Status == "in_progress" {
			now := time.Now()
			interview.StartedAt = &now
		} else if *req.Status == "completed" {
			now := time.Now()
			interview.EndedAt = &now
		}
	}

	if req.Notes != nil {
		interview.Notes = req.Notes
	}

	interview.UpdatedAt = time.Now()

	query := `
		UPDATE video_interviews SET
			scheduled_at = $1, duration_minutes = $2, timezone = $3,
			meeting_link = $4, meeting_provider = $5, meeting_id = $6, meeting_password = $7,
			status = $8, started_at = $9, ended_at = $10, notes = $11, updated_at = $12
		WHERE id = $13
	`

	_, err = s.DB.Exec(query,
		interview.ScheduledAt, interview.DurationMinutes, interview.Timezone,
		interview.MeetingLink, interview.MeetingProvider, interview.MeetingID, interview.MeetingPassword,
		interview.Status, interview.StartedAt, interview.EndedAt, interview.Notes, interview.UpdatedAt,
		id,
	)

	if err != nil {
		return nil, fmt.Errorf("failed to update interview: %w", err)
	}

	return interview, nil
}

func (s *VideoInterviewService) SubmitFeedback(id string, req dto.VideoInterviewFeedbackRequest) (*models.VideoInterview, error) {
	interview, err := s.GetInterviewByID(id)
	if err != nil {
		return nil, err
	}

	if req.InterviewerFeedback != nil {
		interview.InterviewerFeedback = req.InterviewerFeedback
	}

	if req.CandidateFeedback != nil {
		interview.CandidateFeedback = req.CandidateFeedback
	}

	if req.Rating != nil {
		interview.Rating = req.Rating
	}

	interview.UpdatedAt = time.Now()

	query := `
		UPDATE video_interviews SET
			interviewer_feedback = $1, candidate_feedback = $2, rating = $3, updated_at = $4
		WHERE id = $5
	`

	_, err = s.DB.Exec(query,
		interview.InterviewerFeedback, interview.CandidateFeedback, interview.Rating,
		interview.UpdatedAt, id,
	)

	if err != nil {
		return nil, fmt.Errorf("failed to submit feedback: %w", err)
	}

	return interview, nil
}

func (s *VideoInterviewService) DeleteInterview(id string) error {
	result, err := s.DB.Exec("DELETE FROM video_interviews WHERE id = $1", id)
	if err != nil {
		return err
	}

	rowsAffected, _ := result.RowsAffected()
	if rowsAffected == 0 {
		return sql.ErrNoRows
	}

	return nil
}