mvp

db/db.go

@@ -0,0 +1,114 @@
+package db
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"sync"
+)
+
+type DownloadStatus string
+
+var (
+	NotStarted DownloadStatus = "NotStarted"
+	InProgress DownloadStatus = "InProgress"
+	Done       DownloadStatus = "Done"
+	Error      DownloadStatus = "Error"
+)
+
+type Item struct {
+	Id       int            `json:"id"`
+	Date     string         `json:"date"`
+	URL      string         `json:"url"`
+	Title    string         `json:"title"`
+	Approved bool           `json:"approved"`
+	Status   DownloadStatus `json:"status"`
+	FileName string         `json:"file_name"`
+	Progress string         `json:"-"`
+}
+
+type Jdb struct {
+	Items []Item `json:"items"`
+}
+
+type Db struct {
+	items  []Item
+	mutex  sync.Mutex
+	lastId int
+	path   string
+}
+
+func (d *Db) Add(i Item) int {
+	d.mutex.Lock()
+	defer d.mutex.Unlock()
+	i.Id = d.lastId
+	d.lastId++
+	d.items = append(d.items, i)
+	d.save()
+	return i.Id
+}
+
+func (d *Db) Update(id int, persist bool, f func(*Item)) error {
+	d.mutex.Lock()
+	defer d.mutex.Unlock()
+	for i, _ := range d.items {
+		if d.items[i].Id == id {
+			f(&d.items[i])
+			if persist {
+				d.save()
+			}
+			return nil
+		}
+	}
+	return fmt.Errorf("Invalid id: %d", id)
+}
+
+func (d *Db) save() error {
+	data, err := json.Marshal(Jdb{d.items})
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(d.path, data, 0644)
+}
+
+func (d *Db) Run(f func(*Jdb)) {
+	d.mutex.Lock()
+	defer d.mutex.Unlock()
+	f(&Jdb{d.items})
+}
+
+func (d *Db) Save() error {
+	d.mutex.Lock()
+	defer d.mutex.Unlock()
+	return d.save()
+}
+
+func Load(path string) (*Db, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return &Db{
+				path:   path,
+				lastId: 0,
+			}, nil
+		}
+		return nil, err
+	}
+	var jd Jdb
+	err = json.Unmarshal(data, &jd)
+	if err != nil {
+		return nil, err
+	}
+	m := 0
+	for _, item := range jd.Items {
+		if item.Id > m {
+			m = item.Id
+		}
+	}
+	return &Db{
+		items:  jd.Items,
+		path:   path,
+		lastId: m + 1,
+	}, nil
+}