local app = require("lapis").Application()

local db = require("lapis.db")
local constants = require("constants")

local bcrypt = require("bcrypt")
local rand = require("openssl.rand")

local models = require("models")
local Users = models.Users
local Sessions = models.Sessions

local function authenticate_user(user, password)
  return bcrypt.verify(password, user.password_hash)
end

local function create_session_key()
  return rand.bytes(16):gsub(".", function(c) return string.format("%02x", string.byte(c)) end)
end

local function create_session(user_id)
  local days = 30
  local expires_at = os.time() + (days * 24 * 60 * 60)

  return Sessions:create({
    key = create_session_key(),
    user_id = user_id,
    expires_at = expires_at,
  })
end

local function validate_session(session_key)
  local session = db.select('* FROM "sessions" WHERE "key" = ? AND "expires_at" > "?" LIMIT 1', session_key, os.time())
  print(#session)
  if #session > 0 then
    return Users:find({id = session[1].user_id})
  end

  return nil
end

local function validate_password(password)
  if #password < 10 or password:match("%s") then
    return false
  end

  if #password > 255 then
    return false
  end

  local r = password:match("%u+") and
            password:match("%l+") and
            password:match("%d+") and
            password:match("%p+")
  return r ~= nil and true
end

local function validate_username(username)
  if #username < 3 or #username > 20 then
    return false
  end

  return username:match("^[%w_-]+$") and true
end

app:get("user", "/:username", function(self)
  local user = Users:find({username = self.params.username})
  if not user then
    return {status = 404}
  end

  if self.session.flash.just_logged_in then
    self.just_logged_in = true
    self.session.flash = {}
  end
  local me = validate_session(self.session.session_key)
  if not me and user.permission == constants.PermissionLevel.GUEST then
    return {status = 404}
  end
  self.user = user
  return {render = "user.user"}
end)

app:get("user_login", "/login", function(self)
  if self.session.session_key then
    local user = validate_session(self.session.session_key)
    if user ~= nil then
      return {redirect_to = self:url_for("user", {username = user.username})}
    end
  end

  if self.session.flash then
    self.err = self.session.flash.error
    self.session.flash = {}
  end
  return {render = "user.login"}
end)

app:post("user_login", "/login", function(self)
  if self.session.session_key then
    local user = validate_session(self.session.session_key)
    if user ~= nil then
      return {redirect_to = self:url_for("user", {username = user.username})}
    end
  end
  local username = self.params.username
  local password = self.params.password
  local user = Users:find({username = username})
  if not user then
    self.session.flash = {error = "Invalid username or password"}
    return {redirect_to = self:url_for("user_login")}
  end
  if not authenticate_user(user, password) then
    self.session.flash = {error = "Invalid username or password"}
    return {redirect_to = self:url_for("user_login")}
  end
  local session = create_session(user.id)
  self.session.flash = {just_logged_in = true}
  self.session.session_key = session.key
  return {redirect_to = self:url_for("user", {username = username})}
end)

app:get("user_signup", "/signup", function(self)
  if self.session.session_key then
    local user = validate_session(self.session.session_key)
    if user ~= nil then
      return {redirect_to = self:url_for("user", {username = user.username})}
    end
  end
  if self.session.flash then
    self.err = self.session.flash.error
    self.session.flash = {}
  end
  return {render = "user.signup"}
end)

app:post("user_signup", "/signup", function(self)
  if self.session.session_key then
    local user = validate_session(self.session.session_key)
    if user ~= nil then
      return {redirect_to = self:url_for("user", {username = user.username})}
    end
  end

  local username = self.params.username
  local password = self.params.password
  local password2 = self.params.password2
  local user = Users:find({username = username})
  if user then
    self.session.flash = {error = "Username '" .. username .. "' is already taken."}
    return {redirect_to = self:url_for("user_signup")}
  end

  if not validate_username(username) then
    self.session.flash = {error = "Username must be 3-20 characters with only upper and lowercase letters, hyphens, and underscores."}
    return {redirect_to = self:url_for("user_signup")}
  end

  if not validate_password(password) then
    self.session.flash = {error = "Password must be 10+ chars with: 1 uppercase, 1 lowercase, 1 number, 1 special char, and no spaces."}
    return {redirect_to = self:url_for("user_signup")}
  end

  if password ~= password2 then
    self.session.flash = {error = "Passwords do not match."}
    return {redirect_to = self:url_for("user_signup")}
  end

  local new_user = Users:create({
    username = username,
    password_hash = bcrypt.digest(password, constants.BCRYPT_ROUNDS),
    permission = constants.PermissionLevel.GUEST,
  })

  local session = create_session(new_user.id)
  self.session.flash = {just_logged_in = true}
  self.session.session_key = session.key
  return {redirect_to = self:url_for("user", {username = username})}
end)

return app