package models

import (
	"database/sql"
	"errors"
	"os"
	"path/filepath"
	"time"

	_ "modernc.org/sqlite"
)

type DownloadRecord struct {
	ID          int64     `json:"id"`
	URL         string    `json:"url"`
	Source      string    `json:"source"`
	OutputPath  string    `json:"outputPath"`
	Status      string    `json:"status"`
	StartedAt   time.Time `json:"startedAt"`
	CompletedAt time.Time `json:"completedAt,omitempty"`
}

func InitDB(path string) (*sql.DB, error) {
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		return nil, err
	}
	db, err := sql.Open("sqlite", path)
	if err != nil {
		return nil, err
	}

	schema := `
	CREATE TABLE IF NOT EXISTS download_history (
		id INTEGER PRIMARY KEY AUTOINCREMENT,
		url TEXT NOT NULL,
		source TEXT NOT NULL,
		output_path TEXT NOT NULL,
		status TEXT NOT NULL,
		started_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
		completed_at DATETIME
	);
	CREATE INDEX IF NOT EXISTS idx_download_history_url ON download_history(url);
	`

	if _, err := db.Exec(schema); err != nil {
		return nil, err
	}

	return db, nil
}

func InsertDownload(db *sql.DB, url, source, outputPath, status string) (int64, error) {
	res, err := db.Exec(
		`INSERT INTO download_history (url, source, output_path, status) VALUES (?, ?, ?, ?)`,
		url, source, outputPath, status,
	)
	if err != nil {
		return 0, err
	}
	return res.LastInsertId()
}

func MarkDownloadCompleted(db *sql.DB, id int64, status string) error {
	_, err := db.Exec(
		`UPDATE download_history SET status = ?, completed_at = CURRENT_TIMESTAMP WHERE id = ?`,
		status, id,
	)
	return err
}

func FindByURL(db *sql.DB, url string) (*DownloadRecord, error) {
	row := db.QueryRow(
		`SELECT id, url, source, output_path, status, started_at, COALESCE(completed_at, '') FROM download_history WHERE url = ? ORDER BY id DESC LIMIT 1`,
		url,
	)

	var rec DownloadRecord
	var completedRaw string
	if err := row.Scan(&rec.ID, &rec.URL, &rec.Source, &rec.OutputPath, &rec.Status, &rec.StartedAt, &completedRaw); err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return nil, nil
		}
		return nil, err
	}
	if completedRaw != "" {
		parsed, err := time.Parse("2006-01-02 15:04:05", completedRaw)
		if err == nil {
			rec.CompletedAt = parsed
		}
	}
	return &rec, nil
}