go-again/data/jsondb/jsondb.go

package jsondb

import (
	"encoding/json"
	"fmt"
	"net/url"
	"os"
	"strings"

	again "git.rootprojects.org/root/go-again"
)

type JSONDB struct {
	dburl string
	file  *os.File
	json  *dbjson
}

type dbjson struct {
	Schedules []again.Schedule `json:"schedules"`
}

func Connect(dburl string) (*JSONDB, error) {
	u, err := url.Parse(dburl)
	if nil != err {
		return nil, err
	}

	// json:/abspath/to/db.json
	fmt.Println("url.Opaque:", u.Opaque)
	// json:///abspath/to/db.json
	fmt.Println("url.Path:", u.Path)
	fmt.Println(u)

	path := u.Opaque
	if "" == path {
		path = u.Path
		if "" == path {
			// json:relpath/to/db.json
			// json://relpath/to/db.json
			path = strings.TrimSuffix(u.Host+"/"+u.Path, "/")
		}
	}

	f, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE, 0700)
	if nil != err {
		return nil, fmt.Errorf("Couldn't open %q: %s", path, err)
	}

	stat, err := f.Stat()
	if 0 == stat.Size() {
		_, err := f.Write([]byte(`{"schedules":[]}`))
		if nil != err {
			return nil, err
		}
		f, err = os.OpenFile(path, os.O_RDWR|os.O_CREATE, 0700)
		if nil != err {
			return nil, err
		}
	}

	decoder := json.NewDecoder(f)
	db := &dbjson{}
	err = decoder.Decode(db)
	if nil != err {
		return nil, fmt.Errorf("Couldn't parse %q as JSON: %s", path, err)
	}

	return &JSONDB{
		dburl: dburl,
		file:  f,
		json:  db,
	}, nil
}

func (db *JSONDB) List() ([]again.Schedule, error) {
	return db.json.Schedules, nil
}