/*
 Copyright 2020, 2021 Jan Dittberner


 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
*/

package services

import (
	"context"
	"fmt"

	log "github.com/sirupsen/logrus"

	"github.com/BurntSushi/toml"
	"github.com/nicksnyder/go-i18n/v2/i18n"
	"golang.org/x/text/language"
)

func AddMessages(ctx context.Context) {
	messages := make(map[string]*i18n.Message)
	messages["unknown"] = &i18n.Message{
		ID:    "ErrorUnknown",
		Other: "Unknown error",
	}
	messages["TitleRequestConsent"] = &i18n.Message{
		ID:    "TitleRequestConsent",
		Other: "Application requests your consent",
	}
	messages["LabelSubmit"] = &i18n.Message{
		ID:    "LabelSubmit",
		Other: "Submit",
	}
	messages["LabelConsent"] = &i18n.Message{
		ID:    "LabelConsent",
		Other: "I hereby agree that the application may get the requested permissions.",
	}
	messages["IntroConsentRequested"] = &i18n.Message{
		ID:    "IntroConsentRequested",
		Other: "The <strong>{{ .client }}</strong> application requested your consent for the following set of permissions:",
	}
	messages["IntroConsentMoreInformation"] = &i18n.Message{
		ID:    "IntroConsentMoreInformation",
		Other: "You can find more information about <strong>{{ .client }}</strong> at <a href=\"{{ .clientLink }}\">its description page</a>.",
	}
	messages["ClaimsInformation"] = &i18n.Message{
		ID:    "ClaimsInformation",
		Other: "In addition the application wants access to the following information:",
	}
	messages["WrongOrLockedUserOrInvalidPassword"] = &i18n.Message{
		ID:    "WrongOrLockedUserOrInvalidPassword",
		Other: "You entered an invalid username or password or your account has been locked.",
	}
	messages["CertLoginIntroText"] = &i18n.Message{
		ID:    "CertLoginIntroText",
		Other: "The application <strong>{{ .ClientName }}</strong> requests a login.",
	}
	messages["EmailChoiceText"] = &i18n.Message{
		ID:    "EmailChoiceText",
		One:   "You have presented a valid client certificate for the following email address:",
		Other: "You have presented a valid client certificate for multiple email addresses. Please choose which one you want to present to the application:",
	}
	messages["LoginTitle"] = &i18n.Message{
		ID: "LoginTitle",
		Other: "Authenticate with a client certificate",
	}
	messages["CertLoginRequestText"] = &i18n.Message{
		ID:    "CertLoginRequestText",
		Other: "Do you want to use the chosen identity from the certificate for authentication?",
	}
	messages["LabelAcceptCertLogin"] = &i18n.Message{
		ID:          "LabelAcceptCertLogin",
		Description: "Label for a button to accept certificate login",
		Other:       "Yes, please use this identity",
	}
	messages["LabelRejectCertLogin"] = &i18n.Message{
		ID:          "LabelRejectCertLogin",
		Description: "Label for a button to reject certificate login",
		Other:       "No, please send me back",
	}
	messages["LoginDeniedByUser"] = &i18n.Message{
		ID:    "LoginDeniedByUser",
		Other: "Login has been denied by the user.",
	}
	messages["HintChooseAnIdentityForAuthentication"] = &i18n.Message{
		ID:    "HintChooseAnIdentityForAuthentication",
		Other: "Choose an identity for authentication.",
	}
	GetMessageCatalog(ctx).AddMessages(messages)
}

type contextKey int

const (
	ctxI18nBundle contextKey = iota
	ctxI18nCatalog
)

type MessageCatalog struct {
	messages map[string]*i18n.Message
	logger   *log.Logger
}

func (m *MessageCatalog) AddMessages(messages map[string]*i18n.Message) {
	for key, value := range messages {
		m.messages[key] = value
	}
}

func (m *MessageCatalog) LookupErrorMessage(tag string, field string, value interface{}, localizer *i18n.Localizer) string {
	var message *i18n.Message
	message, ok := m.messages[fmt.Sprintf("%s-%s", field, tag)]
	if !ok {
		m.logger.Infof("no specific error message %s-%s", field, tag)
		message, ok = m.messages[tag]
		if !ok {
			m.logger.Infof("no specific error message %s", tag)
			message, ok = m.messages["unknown"]
			if !ok {
				m.logger.Warnf("no default translation found")
				return tag
			}
		}
	}

	translation, err := localizer.Localize(&i18n.LocalizeConfig{
		DefaultMessage: message,
		TemplateData: map[string]interface{}{
			"Value": value,
		},
	})
	if err != nil {
		m.logger.Error(err)
		return tag
	}
	return translation
}

func (m *MessageCatalog) LookupMessage(id string, templateData map[string]interface{}, localizer *i18n.Localizer) string {
	if message, ok := m.messages[id]; ok {
		translation, err := localizer.Localize(&i18n.LocalizeConfig{
			DefaultMessage: message,
			TemplateData:   templateData,
		})
		if err != nil {
			switch err.(type) {
			case *i18n.MessageNotFoundErr:
				m.logger.Warnf("message %s not found: %v", id, err)
				if translation != "" {
					return translation
				}
				break
			default:
				m.logger.Error(err)
			}
			return id
		}
		return translation
	} else {
		m.logger.Warnf("no translation found for %s", id)
		return id
	}
}

func (m *MessageCatalog) LookupMessagePlural(id string, templateData map[string]interface{}, localizer *i18n.Localizer, count int) string {
	if message, ok := m.messages[id]; ok {
		translation, err := localizer.Localize(&i18n.LocalizeConfig{
			DefaultMessage: message,
			TemplateData:   templateData,
			PluralCount:    count,
		})
		if err != nil {
			switch err.(type) {
			case *i18n.MessageNotFoundErr:
				m.logger.Warnf("message %s not found: %v", id, err)
				if translation != "" {
					return translation
				}
				break
			default:
				m.logger.Error(err)
			}
			return id
		}
		return translation
	} else {
		m.logger.Warnf("no translation found for %s", id)
		return id
	}
}

func InitI18n(ctx context.Context, logger *log.Logger, languages []string) context.Context {
	bundle := i18n.NewBundle(language.English)
	bundle.RegisterUnmarshalFunc("toml", toml.Unmarshal)
	for _, lang := range languages {
		_, err := bundle.LoadMessageFile(fmt.Sprintf("active.%s.toml", lang))
		if err != nil {
			logger.Warnln("message bundle de.toml not found")
		}
	}
	catalog := initMessageCatalog(logger)
	ctx = context.WithValue(ctx, ctxI18nBundle, bundle)
	ctx = context.WithValue(ctx, ctxI18nCatalog, catalog)
	return ctx
}

func initMessageCatalog(logger *log.Logger) *MessageCatalog {
	messages := make(map[string]*i18n.Message)
	messages["ErrorTitle"] = &i18n.Message{
		ID:    "ErrorTitle",
		Other: "An error has occurred",
	}
	return &MessageCatalog{messages: messages, logger: logger}
}

func GetI18nBundle(ctx context.Context) *i18n.Bundle {
	return ctx.Value(ctxI18nBundle).(*i18n.Bundle)
}

func GetMessageCatalog(ctx context.Context) *MessageCatalog {
	return ctx.Value(ctxI18nCatalog).(*MessageCatalog)
}