package character

import (
	"errors"
	"log"
	"strconv"
	"strings"

	"git.aiterp.net/rpdata/api/internal/store"
	"git.aiterp.net/rpdata/api/model/counter"
	"github.com/globalsign/mgo"
	"github.com/globalsign/mgo/bson"
)

var collection *mgo.Collection

// Character is a common data model representing an RP character or NPC.
type Character struct {
	ID          string   `json:"id" bson:"_id"`
	Nicks       []string `json:"nicks" bson:"nicks"`
	Name        string   `json:"name" bson:"name"`
	ShortName   string   `json:"shortName" bson:"shortName"`
	Author      string   `json:"author" bson:"author"`
	Description string   `json:"description" bson:"description"`
}

// HasNick returns true if the character has that nick
func (character *Character) HasNick(nick string) bool {
	for i := range character.Nicks {
		if strings.EqualFold(character.Nicks[i], nick) {
			return true
		}
	}

	return false
}

// AddNick adds a nick to the character. It will return an error
// if the nick already exists.
func (character *Character) AddNick(nick string) error {
	for i := range character.Nicks {
		if strings.EqualFold(character.Nicks[i], nick) {
			return errors.New("Nick already exists")
		}
	}

	err := collection.UpdateId(character.ID, bson.M{"$push": bson.M{"nicks": nick}})
	if err != nil {
		return err
	}

	character.Nicks = append(character.Nicks, nick)

	return nil
}

// RemoveNick removes the nick from the character. It will raise
// an error if the nick does not exist; even if that kind of is
// the end goal.
func (character *Character) RemoveNick(nick string) error {
	index := -1
	for i := range character.Nicks {
		if strings.EqualFold(character.Nicks[i], nick) {
			index = i
			break
		}
	}
	if index == -1 {
		return errors.New("Nick does not exist")
	}

	err := collection.UpdateId(character.ID, bson.M{"$pull": bson.M{"nicks": nick}})
	if err != nil {
		return err
	}

	character.Nicks = append(character.Nicks[:index], character.Nicks[index+1:]...)

	return nil
}

// Edit sets the fields of metadata. Only non-empty and different fields will be set in the
// database, preventing out of order edits to two fields from conflicting
func (character *Character) Edit(name, shortName, description string) error {
	changes := bson.M{}
	if len(name) > 0 && name != character.Name {
		changes["name"] = name
	}
	if len(shortName) > 0 && shortName != character.ShortName {
		changes["shortName"] = shortName
	}
	if len(description) > 0 && description != character.Description {
		changes["description"] = description
	}

	err := collection.UpdateId(character.ID, changes)
	if err != nil {
		return err
	}

	if changes["name"] != nil {
		character.Name = name
	}
	if changes["shortName"] != nil {
		character.ShortName = shortName
	}
	if changes["description"] != nil {
		character.Description = description
	}

	return nil
}

// Remove removes the character from the database. The reason this is an instance method
// is that it should only be done after an authorization check.
func (character *Character) Remove() error {
	return collection.RemoveId(character.ID)
}

// FindID finds Character by ID
func FindID(id string) (Character, error) {
	return find(bson.M{"_id": id})
}

// FindNick finds Character by nick
func FindNick(nick string) (Character, error) {
	return find(bson.M{"nicks": nick})
}

// FindName finds Character by either full name or
// short name.
func FindName(name string) (Character, error) {
	return find(bson.M{"$or": []bson.M{bson.M{"name": name}, bson.M{"shortName": name}}})
}

// List lists all characters
func List() ([]Character, error) {
	return list(bson.M{})
}

// ListAuthor lists all characters by author
func ListAuthor(author string) ([]Character, error) {
	return list(bson.M{"author": author})
}

// ListNicks lists all characters with either of these nicks. This was made with
// the logbot in mind, to batch an order for characters.
func ListNicks(nicks ...string) ([]Character, error) {
	return list(bson.M{"nicks": bson.M{"$in": nicks}})
}

// ListIDs lists all characters with either of these IDs.
func ListIDs(ids ...string) ([]Character, error) {
	return list(bson.M{"_id": bson.M{"$in": ids}})
}

// New creates a Character and pushes it to the database. It does some validation
// on nick, name, shortName and author. Leave the shortname blank to have it be the
// first name.
func New(nick, name, shortName, author, description string) (Character, error) {
	if len(nick) < 1 || len(name) < 1 || len(author) < 1 {
		return Character{}, errors.New("Nick, name, or author name too short or empty")
	}
	if shortName == "" {
		shortName = strings.SplitN(name, " ", 2)[0]
	}

	char, err := FindNick(nick)
	if err == nil && char.ID != "" {
		return Character{}, errors.New("Nick is occupied")
	}

	nextID, err := counter.Next("auto_increment", "Character")
	if err != nil {
		return Character{}, err
	}

	character := Character{
		ID:          "C" + strconv.Itoa(nextID),
		Nicks:       []string{nick},
		Name:        name,
		ShortName:   shortName,
		Author:      author,
		Description: description,
	}

	err = collection.Insert(character)
	if err != nil {
		return Character{}, err
	}

	return character, nil
}

func find(query interface{}) (Character, error) {
	character := Character{}
	err := collection.Find(query).One(&character)
	if err != nil {
		return Character{}, err
	}

	return character, nil
}

func list(query interface{}) ([]Character, error) {
	characters := make([]Character, 0, 64)
	err := collection.Find(query).All(&characters)
	if err != nil {
		return nil, err
	}

	return characters, nil
}

func init() {
	store.HandleInit(func(db *mgo.Database) {
		collection = db.C("common.characters")

		collection.EnsureIndexKey("name")
		collection.EnsureIndexKey("shortName")
		collection.EnsureIndexKey("author")
		err := collection.EnsureIndex(mgo.Index{
			Key:      []string{"nicks"},
			Unique:   true,
			DropDups: true,
		})
		if err != nil {
			log.Fatalln("init common.characters:", err)
		}
	})
}