movies/collection.go

package movies

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"sync"
)

type Collection struct {
	Movies   []*Movie
	movieMap map[string]*Movie

	Lists   []*List
	listMap map[string]*List

	mutex      sync.RWMutex
	hasChanged bool
}

func Import(filename string) (*Collection, error) {
	b, err := ioutil.ReadFile(filename)
	if err != nil {
		return nil, err
	}

	var c Collection
	if err := json.Unmarshal(b, &c); err != nil {
		return nil, err
	}

	c.movieMap = make(map[string]*Movie)
	for _, m := range c.Movies {
		m.FillFromOMDB()
		c.movieMap[m.IMDBID] = m
	}

	c.listMap = make(map[string]*List)
	for _, l := range c.Lists {
		c.listMap[l.ID] = l
	}

	return &c, nil
}

func (c *Collection) Export(filename string) error {
	c.mutex.RLock()
	defer c.mutex.RUnlock()

	b, err := json.Marshal(c)
	if err != nil {
		return err
	}

	err = ioutil.WriteFile(filename, b, 0644)
	if err != nil {
		return err
	}

	c.hasChanged = false
	return nil
}

func (c *Collection) Add(m *Movie) {
	c.mutex.Lock()
	defer c.mutex.Unlock()

	c.hasChanged = true

	for _, present := range c.Movies {
		if m.IMDBID == present.IMDBID {
			present.OMDB = m.OMDB
			present.FillFromOMDB()
			return
		}
	}

	c.Movies = append(c.Movies, m)
	c.movieMap[m.IMDBID] = m
}

func (c *Collection) HasChanged() bool {
	return c.hasChanged
}

func (c *Collection) Get(imdbID string) (*Movie, bool) {
	c.mutex.RLock()
	defer c.mutex.RUnlock()

	m, ok := c.movieMap[imdbID]
	return m, ok
}

func (c *Collection) Update(m *Movie) {
	c.mutex.Lock()
	defer c.mutex.Unlock()

	c.movieMap[m.IMDBID] = m

	found := false
	for i := range c.Movies {
		if c.Movies[i].IMDBID == m.IMDBID {
			c.Movies[i] = m
			found = true
			break
		}
	}
	if !found {
		c.Movies = append(c.Movies, m)
	}

	c.hasChanged = true
}

func (c *Collection) GetList(listID string) (*List, bool) {
	c.mutex.RLock()
	defer c.mutex.RUnlock()

	l, ok := c.listMap[listID]
	return l, ok
}

func (c *Collection) AddList(id, title string) error {
	c.mutex.Lock()
	defer c.mutex.Unlock()

	c.hasChanged = true

	for _, present := range c.Lists {
		if id == present.ID {
			return fmt.Errorf("there is already a list with id %q", id)
		}
	}

	l := &List{
		ID:    id,
		Title: title,
	}

	c.Lists = append(c.Lists, l)
	c.listMap[l.ID] = l

	return nil
}

func (c *Collection) UpdateList(l *List) {
	c.mutex.Lock()
	defer c.mutex.Unlock()

	c.listMap[l.ID] = l

	found := false
	for i := range c.Lists {
		if c.Lists[i].ID == l.ID {
			c.Lists[i] = l
			found = true
			break
		}
	}
	if !found {
		c.Lists = append(c.Lists, l)
	}

	c.hasChanged = true
}