package main

import "log"
import "sync"
import "errors"
import "strings"
import "strconv"
import "database/sql"

import "./query_gen/lib"
import "golang.org/x/crypto/bcrypt"

// TO-DO: Add the watchdog goroutine
var users UserStore
var err_account_exists = errors.New("This username is already in use.")

type UserStore interface {
	Load(id int) error
	Get(id int) (*User, error)
	GetUnsafe(id int) (*User, error)
	CascadeGet(id int) (*User, error)
	BypassGet(id int) (*User, error)
	Set(item *User) error
	Add(item *User) error
	AddUnsafe(item *User) error
	Remove(id int) error
	RemoveUnsafe(id int) error
	CreateUser(username string, password string, email string, group int, active int) (int, error)
	GetLength() int
	GetCapacity() int
}

type MemoryUserStore struct {
	items map[int]*User
	length int
	capacity int
	get *sql.Stmt
	register *sql.Stmt
	username_exists *sql.Stmt
	sync.RWMutex
}

func NewMemoryUserStore(capacity int) *MemoryUserStore {
	get_stmt, err := qgen.Builder.SimpleSelect("users","name, group, is_super_admin, session, email, avatar, message, url_prefix, url_name, level, score, last_ip","uid = ?","","")
	if err != nil {
		log.Fatal(err)
	}

	// Add an admin version of register_stmt with more flexibility?
	// create_account_stmt, err = db.Prepare("INSERT INTO
	register_stmt, err := qgen.Builder.SimpleInsert("users","name, email, password, salt, group, is_super_admin, session, active, message","?,?,?,?,?,0,'',?,''")
	if err != nil {
		log.Fatal(err)
	}

	username_exists_stmt, err := qgen.Builder.SimpleSelect("users","name","name = ?","","")
	if err != nil {
		log.Fatal(err)
	}

	return &MemoryUserStore{
		items:make(map[int]*User),
		capacity:capacity,
		get:get_stmt,
		register:register_stmt,
		username_exists:username_exists_stmt,
	}
}

func (sus *MemoryUserStore) Get(id int) (*User, error) {
	sus.RLock()
	item, ok := sus.items[id]
	sus.RUnlock()
	if ok {
		return item, nil
	}
	return item, ErrNoRows
}

func (sus *MemoryUserStore) GetUnsafe(id int) (*User, error) {
	item, ok := sus.items[id]
	if ok {
		return item, nil
	}
	return item, ErrNoRows
}

func (sus *MemoryUserStore) CascadeGet(id int) (*User, error) {
	sus.RLock()
	user, ok := sus.items[id]
	sus.RUnlock()
	if ok {
		return user, nil
	}

	user = &User{ID:id,Loggedin:true}
	err := sus.get.QueryRow(id).Scan(&user.Name, &user.Group, &user.Is_Super_Admin, &user.Session, &user.Email, &user.Avatar, &user.Message, &user.URLPrefix, &user.URLName, &user.Level, &user.Score, &user.Last_IP)

	if user.Avatar != "" {
		if user.Avatar[0] == '.' {
			user.Avatar = "/uploads/avatar_" + strconv.Itoa(user.ID) + user.Avatar
		}
	} else {
		user.Avatar = strings.Replace(config.Noavatar,"{id}",strconv.Itoa(user.ID),1)
	}
	user.Link = build_profile_url(name_to_slug(user.Name),id)
	user.Tag = groups[user.Group].Tag
	init_user_perms(user)
	if err == nil {
		sus.Set(user)
	}
	return user, err
}

func (sus *MemoryUserStore) BypassGet(id int) (*User, error) {
	user := &User{ID:id,Loggedin:true}
	err := sus.get.QueryRow(id).Scan(&user.Name, &user.Group, &user.Is_Super_Admin, &user.Session, &user.Email, &user.Avatar, &user.Message, &user.URLPrefix, &user.URLName, &user.Level, &user.Score, &user.Last_IP)

	if user.Avatar != "" {
		if user.Avatar[0] == '.' {
			user.Avatar = "/uploads/avatar_" + strconv.Itoa(user.ID) + user.Avatar
		}
	} else {
		user.Avatar = strings.Replace(config.Noavatar,"{id}",strconv.Itoa(user.ID),1)
	}
	user.Link = build_profile_url(name_to_slug(user.Name),id)
	user.Tag = groups[user.Group].Tag
	init_user_perms(user)
	return user, err
}

func (sus *MemoryUserStore) Load(id int) error {
	user := &User{ID:id,Loggedin:true}
	err := sus.get.QueryRow(id).Scan(&user.Name, &user.Group, &user.Is_Super_Admin, &user.Session, &user.Email, &user.Avatar, &user.Message, &user.URLPrefix, &user.URLName, &user.Level, &user.Score, &user.Last_IP)
	if err != nil {
		sus.Remove(id)
		return err
	}

	if user.Avatar != "" {
		if user.Avatar[0] == '.' {
			user.Avatar = "/uploads/avatar_" + strconv.Itoa(user.ID) + user.Avatar
		}
	} else {
		user.Avatar = strings.Replace(config.Noavatar,"{id}",strconv.Itoa(user.ID),1)
	}
	user.Link = build_profile_url(name_to_slug(user.Name),id)
	user.Tag = groups[user.Group].Tag
	init_user_perms(user)
	sus.Set(user)
	return nil
}

func (sus *MemoryUserStore) Set(item *User) error {
	sus.Lock()
	user, ok := sus.items[item.ID]
	if ok {
		sus.Unlock()
		*user = *item
	} else if sus.length >= sus.capacity {
		sus.Unlock()
		return ErrStoreCapacityOverflow
	} else {
		sus.items[item.ID] = item
		sus.Unlock()
		sus.length++
	}
	return nil
}

func (sus *MemoryUserStore) Add(item *User) error {
	if sus.length >= sus.capacity {
		return ErrStoreCapacityOverflow
	}
	sus.Lock()
	sus.items[item.ID] = item
	sus.Unlock()
	sus.length++
	return nil
}

func (sus *MemoryUserStore) AddUnsafe(item *User) error {
	if sus.length >= sus.capacity {
		return ErrStoreCapacityOverflow
	}
	sus.items[item.ID] = item
	sus.length++
	return nil
}

func (sus *MemoryUserStore) Remove(id int) error {
	sus.Lock()
	delete(sus.items,id)
	sus.Unlock()
	sus.length--
	return nil
}

func (sus *MemoryUserStore) RemoveUnsafe(id int) error {
	delete(sus.items,id)
	sus.length--
	return nil
}

func (sus *MemoryUserStore) CreateUser(username string, password string, email string, group int, active int) (int, error) {
	// Is this username already taken..?
	err := sus.username_exists.QueryRow(username).Scan(&username)
	if err != ErrNoRows {
		return 0, err_account_exists
	}

	salt, err := GenerateSafeString(saltLength)
	if err != nil {
		return 0, err
	}

	hashed_password, err := bcrypt.GenerateFromPassword([]byte(password + salt), bcrypt.DefaultCost)
	if err != nil {
		return 0, err
	}

	res, err := sus.register.Exec(username,email,string(hashed_password),salt,group,active)
	if err != nil {
		return 0, err
	}

	lastId, err := res.LastInsertId()
	return int(lastId), err
}

func (sus *MemoryUserStore) GetLength() int {
	return sus.length
}

func (sus *MemoryUserStore) SetCapacity(capacity int) {
	sus.capacity = capacity
}

func (sus *MemoryUserStore) GetCapacity() int {
	return sus.capacity
}

type SqlUserStore struct {
	get *sql.Stmt
	register *sql.Stmt
	username_exists *sql.Stmt
}

func NewSqlUserStore() *SqlUserStore {
	get_stmt, err := qgen.Builder.SimpleSelect("users","name, group, is_super_admin, session, email, avatar, message, url_prefix, url_name, level, score, last_ip","uid = ?","","")
	if err != nil {
		log.Fatal(err)
	}

	// Add an admin version of register_stmt with more flexibility?
	// create_account_stmt, err = db.Prepare("INSERT INTO
	register_stmt, err := qgen.Builder.SimpleInsert("users","name, email, password, salt, group, is_super_admin, session, active, message","?,?,?,?,?,0,'',?,''")
	if err != nil {
		log.Fatal(err)
	}

	username_exists_stmt, err := qgen.Builder.SimpleSelect("users","name","name = ?","","")
	if err != nil {
		log.Fatal(err)
	}

	return &SqlUserStore{
		get:get_stmt,
		register:register_stmt,
		username_exists:username_exists_stmt,
	}
}

func (sus *SqlUserStore) Get(id int) (*User, error) {
	user := User{ID:id,Loggedin:true}
	err := sus.get.QueryRow(id).Scan(&user.Name, &user.Group, &user.Is_Super_Admin, &user.Session, &user.Email, &user.Avatar, &user.Message, &user.URLPrefix, &user.URLName, &user.Level, &user.Score, &user.Last_IP)

	if user.Avatar != "" {
		if user.Avatar[0] == '.' {
			user.Avatar = "/uploads/avatar_" + strconv.Itoa(user.ID) + user.Avatar
		}
	} else {
		user.Avatar = strings.Replace(config.Noavatar,"{id}",strconv.Itoa(user.ID),1)
	}
	user.Link = build_profile_url(name_to_slug(user.Name),id)
	user.Tag = groups[user.Group].Tag
	init_user_perms(&user)
	return &user, err
}

func (sus *SqlUserStore) GetUnsafe(id int) (*User, error) {
	user := User{ID:id,Loggedin:true}
	err := sus.get.QueryRow(id).Scan(&user.Name, &user.Group, &user.Is_Super_Admin, &user.Session, &user.Email, &user.Avatar, &user.Message, &user.URLPrefix, &user.URLName, &user.Level, &user.Score, &user.Last_IP)

	if user.Avatar != "" {
		if user.Avatar[0] == '.' {
			user.Avatar = "/uploads/avatar_" + strconv.Itoa(user.ID) + user.Avatar
		}
	} else {
		user.Avatar = strings.Replace(config.Noavatar,"{id}",strconv.Itoa(user.ID),1)
	}
	user.Link = build_profile_url(name_to_slug(user.Name),id)
	user.Tag = groups[user.Group].Tag
	init_user_perms(&user)
	return &user, err
}

func (sus *SqlUserStore) CascadeGet(id int) (*User, error) {
	user := User{ID:id,Loggedin:true}
	err := sus.get.QueryRow(id).Scan(&user.Name, &user.Group, &user.Is_Super_Admin, &user.Session, &user.Email, &user.Avatar, &user.Message, &user.URLPrefix, &user.URLName, &user.Level, &user.Score, &user.Last_IP)

	if user.Avatar != "" {
		if user.Avatar[0] == '.' {
			user.Avatar = "/uploads/avatar_" + strconv.Itoa(user.ID) + user.Avatar
		}
	} else {
		user.Avatar = strings.Replace(config.Noavatar,"{id}",strconv.Itoa(user.ID),1)
	}
	user.Link = build_profile_url(name_to_slug(user.Name),id)
	user.Tag = groups[user.Group].Tag
	init_user_perms(&user)
	return &user, err
}

func (sus *SqlUserStore) BypassGet(id int) (*User, error) {
	user := User{ID:id,Loggedin:true}
	err := sus.get.QueryRow(id).Scan(&user.Name, &user.Group, &user.Is_Super_Admin, &user.Session, &user.Email, &user.Avatar, &user.Message, &user.URLPrefix, &user.URLName, &user.Level, &user.Score, &user.Last_IP)

	if user.Avatar != "" {
		if user.Avatar[0] == '.' {
			user.Avatar = "/uploads/avatar_" + strconv.Itoa(user.ID) + user.Avatar
		}
	} else {
		user.Avatar = strings.Replace(config.Noavatar,"{id}",strconv.Itoa(user.ID),1)
	}
	user.Link = build_profile_url(name_to_slug(user.Name),id)
	user.Tag = groups[user.Group].Tag
	init_user_perms(&user)
	return &user, err
}

func (sus *SqlUserStore) Load(id int) error {
	user := &User{ID:id}
	// Simplify this into a quick check whether the user exists
	err := sus.get.QueryRow(id).Scan(&user.Name, &user.Group, &user.Is_Super_Admin, &user.Session, &user.Email, &user.Avatar, &user.Message, &user.URLPrefix, &user.URLName, &user.Level, &user.Score, &user.Last_IP)
	return err
}

func (sus *SqlUserStore) CreateUser(username string, password string, email string, group int, active int) (int, error) {
	// Is this username already taken..?
	err := sus.username_exists.QueryRow(username).Scan(&username)
	if err != ErrNoRows {
		return 0, err_account_exists
	}

	salt, err := GenerateSafeString(saltLength)
	if err != nil {
		return 0, err
	}

	hashed_password, err := bcrypt.GenerateFromPassword([]byte(password + salt), bcrypt.DefaultCost)
	if err != nil {
		return 0, err
	}

	res, err := sus.register.Exec(username,email,string(hashed_password),salt,group,active)
	if err != nil {
		return 0, err
	}

	lastId, err := res.LastInsertId()
	return int(lastId), err
}

// Placeholder methods, as we're not don't need to do any cache management with this implementation ofr the UserStore
func (sus *SqlUserStore) Set(item *User) error {
	return nil
}
func (sus *SqlUserStore) Add(item *User) error {
	return nil
}
func (sus *SqlUserStore) AddUnsafe(item *User) error {
	return nil
}
func (sus *SqlUserStore) Remove(id int) error {
	return nil
}
func (sus *SqlUserStore) RemoveUnsafe(id int) error {
	return nil
}
func (sus *SqlUserStore) GetCapacity() int {
	return 0
}

func (sus *SqlUserStore) GetLength() int {
	return 0 // Return the total number of users registered on the forums?
}