package store

import (
	"context"
	"database/sql"
	"errors"
	"time"
)

type CloneJobStatus string

const (
	CloneJobPending   CloneJobStatus = "pending"
	CloneJobRunning   CloneJobStatus = "running"
	CloneJobCompleted CloneJobStatus = "completed"
	CloneJobFailed    CloneJobStatus = "failed"
)

type CloneJob struct {
	ID         int64
	RepoID     int64
	Status     CloneJobStatus
	StartedAt  *time.Time
	FinishedAt *time.Time
	Error      *string
	CreatedAt  time.Time
}

type CloneJobStore interface {
	CreateCloneJob(ctx context.Context, repoID int64) (int64, error)
	GetCloneJob(ctx context.Context, id int64) (*CloneJob, error)
	GetLatestCloneJob(ctx context.Context, repoID int64) (*CloneJob, error)
	HasRunningCloneJob(ctx context.Context, repoID int64) (bool, error)
	MarkCloneJobStarted(ctx context.Context, id int64) error
	MarkCloneJobFinished(ctx context.Context, id int64, status CloneJobStatus, errMsg *string) error
}

type SQLiteCloneJobStore struct {
	db *sql.DB
}

func NewCloneJobStore(db *sql.DB) *SQLiteCloneJobStore {
	return &SQLiteCloneJobStore{db: db}
}

func (s *SQLiteCloneJobStore) CreateCloneJob(ctx context.Context, repoID int64) (int64, error) {
	res, err := s.db.ExecContext(ctx, `INSERT INTO clone_jobs (repo_id) VALUES (?)`, repoID)
	if err != nil {
		return 0, err
	}
	return res.LastInsertId()
}

func (s *SQLiteCloneJobStore) GetCloneJob(ctx context.Context, id int64) (*CloneJob, error) {
	row := s.db.QueryRowContext(ctx,
		`SELECT id, repo_id, status, started_at, finished_at, error, created_at FROM clone_jobs WHERE id = ?`, id)
	return scanCloneJob(row)
}

func (s *SQLiteCloneJobStore) GetLatestCloneJob(ctx context.Context, repoID int64) (*CloneJob, error) {
	row := s.db.QueryRowContext(ctx,
		`SELECT id, repo_id, status, started_at, finished_at, error, created_at FROM clone_jobs WHERE repo_id = ? ORDER BY created_at DESC LIMIT 1`, repoID)
	return scanCloneJob(row)
}

func (s *SQLiteCloneJobStore) HasRunningCloneJob(ctx context.Context, repoID int64) (bool, error) {
	var count int
	err := s.db.QueryRowContext(ctx,
		`SELECT COUNT(*) FROM clone_jobs WHERE repo_id = ? AND status IN ('pending','running')`, repoID,
	).Scan(&count)
	return count > 0, err
}

func (s *SQLiteCloneJobStore) MarkCloneJobStarted(ctx context.Context, id int64) error {
	_, err := s.db.ExecContext(ctx,
		`UPDATE clone_jobs SET status='running', started_at=CURRENT_TIMESTAMP WHERE id=?`, id)
	return err
}

func (s *SQLiteCloneJobStore) MarkCloneJobFinished(ctx context.Context, id int64, status CloneJobStatus, errMsg *string) error {
	_, err := s.db.ExecContext(ctx,
		`UPDATE clone_jobs SET status=?, finished_at=CURRENT_TIMESTAMP, error=? WHERE id=?`,
		status, errMsg, id)
	return err
}

func scanCloneJob(row *sql.Row) (*CloneJob, error) {
	var j CloneJob
	var startedAt, finishedAt sql.NullTime
	var errMsg sql.NullString

	err := row.Scan(&j.ID, &j.RepoID, &j.Status, &startedAt, &finishedAt, &errMsg, &j.CreatedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return nil, ErrNotFound
	}
	if err != nil {
		return nil, err
	}
	if startedAt.Valid {
		j.StartedAt = &startedAt.Time
	}
	if finishedAt.Valid {
		j.FinishedAt = &finishedAt.Time
	}
	if errMsg.Valid {
		j.Error = &errMsg.String
	}
	return &j, nil
}