package chapters

import (
	"crypto/rand"
	"encoding/binary"
	"strconv"

	"git.aiterp.net/rpdata/api/internal/store"
	"git.aiterp.net/rpdata/api/models"
	"github.com/globalsign/mgo"
)

var collection *mgo.Collection
var storyCollection *mgo.Collection

func find(query interface{}) (*models.Chapter, error) {
	chapter := models.Chapter{}
	err := collection.Find(query).One(&chapter)
	if err != nil {
		return nil, err
	}

	return &chapter, err
}

func list(query interface{}) ([]models.Chapter, error) {
	chapters := make([]models.Chapter, 0, 8)
	err := collection.Find(query).Sort("createdDate").All(&chapters)
	if err != nil {
		return nil, err
	}

	return chapters, nil
}

func makeChapterID() string {
	result := "SC"
	offset := 0
	data := make([]byte, 32)

	rand.Read(data)
	for len(result) < 24 {
		result += strconv.FormatUint(binary.LittleEndian.Uint64(data[offset:]), 36)
		offset += 8

		if offset >= 32 {
			rand.Read(data)
			offset = 0
		}
	}

	return result[:24]
}

func init() {
	store.HandleInit(func(db *mgo.Database) {
		collection = db.C("story.chapters")
		storyCollection = db.C("story.stories")

		collection.EnsureIndexKey("storyId")
		collection.EnsureIndexKey("author")
		collection.EnsureIndexKey("createdDate")
	})
}