package main

import (
	"crypto/sha1"
	"io"
	"os"
	"path"
)

type EFile struct {
	Id          int64  `json:"id"`
	Path        string `json:"path"`
	IdExercice  int64  `json:"idExercice"`
	Name        string `json:"name"`
	Checksum    []byte `json:"checksum"`
}

func (e Exercice) GetFiles() ([]EFile, error) {
	if rows, err := DBQuery("SELECT id_file, path, name, sha1 FROM exercice_files WHERE id_exercice = ?", e.Id); err != nil {
		return nil, err
	} else {
		defer rows.Close()

		var files = make([]EFile, 0)
		for rows.Next() {
			var f EFile
			f.IdExercice = e.Id
			if err := rows.Scan(&f.Id, &f.Path, &f.Name, &f.Checksum); err != nil {
				return nil, err
			}
			files = append(files, f)
		}
		if err := rows.Err(); err != nil {
			return nil, err
		}

		return files, nil
	}
}

func (e Exercice) ImportFile(filePath string) (EFile, error) {
	if fd, err := os.Open(filePath); err != nil {
		return EFile{}, err
	} else {
		defer fd.Close()

		hash := sha1.New()
		if _, err := io.Copy(hash, fd); err != nil {
			return EFile{}, err
		}

		var result []byte
		return e.AddFile(filePath, path.Base(filePath), hash.Sum(result))
	}
}

func (e Exercice) AddFile(path string, name string, checksum []byte) (EFile, error) {
	if res, err := DBExec("INSERT INTO exercice_files (id_exercice, path, name, sha1) VALUES (?, ?, ?, ?)", e.Id, path, name, checksum); err != nil {
		return EFile{}, err
	} else if fid, err := res.LastInsertId(); err != nil {
		return EFile{}, err
	} else {
		return EFile{fid, path, e.Id, name, checksum}, nil
	}
}

func (f EFile) Update() (int64, error) {
	if res, err := DBExec("UPDATE exercice_files SET id_exercice = ?, path = ?, name = ?, sha1 = ? WHERE id_file = ?", f.IdExercice, f.Path, f.Name, f.Checksum, f.Id); err != nil {
		return 0, err
	} else if nb, err := res.RowsAffected(); err != nil {
		return 0, err
	} else {
		return nb, err
	}
}

func (f EFile) Delete() (int64, error) {
	if res, err := DBExec("DELETE FROM exercice_files WHERE id_file = ?", f.Id); err != nil {
		return 0, err
	} else if nb, err := res.RowsAffected(); err != nil {
		return 0, err
	} else {
		return nb, err
	}
}