// Vikunja is a to-do list application to facilitate your life.
// Copyright 2018-present Vikunja and contributors. All rights reserved.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package shared

import (
	"code.vikunja.io/api/pkg/config"
	"code.vikunja.io/api/pkg/license"
	"code.vikunja.io/api/pkg/log"
	"code.vikunja.io/api/pkg/modules/auth/openid"
	csvmigrator "code.vikunja.io/api/pkg/modules/migration/csv"
	microsofttodo "code.vikunja.io/api/pkg/modules/migration/microsoft-todo"
	"code.vikunja.io/api/pkg/modules/migration/ticktick"
	"code.vikunja.io/api/pkg/modules/migration/todoist"
	"code.vikunja.io/api/pkg/modules/migration/trello"
	vikunja_file "code.vikunja.io/api/pkg/modules/migration/vikunja-file"
	"code.vikunja.io/api/pkg/modules/migration/wekan"
	"code.vikunja.io/api/pkg/version"
)

// VikunjaInfos holds public information about this Vikunja instance.
type VikunjaInfos struct {
	Version                    string            `json:"version" doc:"The Vikunja version this instance runs."`
	FrontendURL                string            `json:"frontend_url" doc:"The publicly configured frontend URL of this instance."`
	Motd                       string            `json:"motd" doc:"The message of the day, shown to all users."`
	LinkSharingEnabled         bool              `json:"link_sharing_enabled" doc:"Whether sharing projects via public links is enabled."`
	MaxFileSize                string            `json:"max_file_size" doc:"The maximum allowed upload size, as a human-readable string (e.g. 20MB)."`
	MaxItemsPerPage            int               `json:"max_items_per_page" doc:"The maximum number of items a paginated endpoint returns per page."`
	AvailableMigrators         []string          `json:"available_migrators" doc:"The migrators enabled on this instance."`
	TaskAttachmentsEnabled     bool              `json:"task_attachments_enabled" doc:"Whether task attachments are enabled."`
	EnabledBackgroundProviders []string          `json:"enabled_background_providers" doc:"The project-background providers enabled on this instance (e.g. upload, unsplash)."`
	TotpEnabled                bool              `json:"totp_enabled" doc:"Whether TOTP two-factor authentication is enabled."`
	Legal                      LegalInfo         `json:"legal" doc:"Links to the instance's legal documents."`
	CaldavEnabled              bool              `json:"caldav_enabled" doc:"Whether the CalDAV interface is enabled."`
	AuthInfo                   AuthInfo          `json:"auth" doc:"The authentication methods enabled on this instance."`
	EmailRemindersEnabled      bool              `json:"email_reminders_enabled" doc:"Whether email reminders are enabled."`
	UserDeletionEnabled        bool              `json:"user_deletion_enabled" doc:"Whether users may delete their own account."`
	TaskCommentsEnabled        bool              `json:"task_comments_enabled" doc:"Whether task comments are enabled."`
	DemoModeEnabled            bool              `json:"demo_mode_enabled" doc:"Whether this instance runs in demo mode (data is periodically reset)."`
	WebhooksEnabled            bool              `json:"webhooks_enabled" doc:"Whether webhooks are enabled."`
	PublicTeamsEnabled         bool              `json:"public_teams_enabled" doc:"Whether public teams are enabled."`
	AllowIconChanges           bool              `json:"allow_icon_changes" doc:"Whether users may change project icons."`
	EnabledProFeatures         []license.Feature `json:"enabled_pro_features" doc:"The licensed pro features enabled on this instance."`
}

// AuthInfo describes the authentication methods enabled on this instance.
type AuthInfo struct {
	Local         LocalAuthInfo  `json:"local"`
	Ldap          LdapAuthInfo   `json:"ldap"`
	OpenIDConnect OpenIDAuthInfo `json:"openid_connect"`
}

// LocalAuthInfo describes the local (username/password) authentication method.
type LocalAuthInfo struct {
	Enabled             bool `json:"enabled"`
	RegistrationEnabled bool `json:"registration_enabled"`
}

// LdapAuthInfo describes the LDAP authentication method.
type LdapAuthInfo struct {
	Enabled bool `json:"enabled"`
}

// OpenIDAuthInfo describes the OpenID Connect authentication method.
type OpenIDAuthInfo struct {
	Enabled   bool               `json:"enabled"`
	Providers []*openid.Provider `json:"providers"`
}

// LegalInfo holds links to the instance's legal documents.
type LegalInfo struct {
	ImprintURL       string `json:"imprint_url"`
	PrivacyPolicyURL string `json:"privacy_policy_url"`
}

// BuildInfo assembles the public instance information returned by GET /info on
// both API versions.
func BuildInfo() VikunjaInfos {
	info := VikunjaInfos{
		Version:                version.Version,
		FrontendURL:            config.ServicePublicURL.GetString(),
		Motd:                   config.ServiceMotd.GetString(),
		LinkSharingEnabled:     config.ServiceEnableLinkSharing.GetBool(),
		MaxFileSize:            config.FilesMaxSize.GetString(),
		MaxItemsPerPage:        config.ServiceMaxItemsPerPage.GetInt(),
		TaskAttachmentsEnabled: config.ServiceEnableTaskAttachments.GetBool(),
		TotpEnabled:            config.ServiceEnableTotp.GetBool(),
		CaldavEnabled:          config.ServiceEnableCaldav.GetBool(),
		EmailRemindersEnabled:  config.ServiceEnableEmailReminders.GetBool(),
		UserDeletionEnabled:    config.ServiceEnableUserDeletion.GetBool(),
		TaskCommentsEnabled:    config.ServiceEnableTaskComments.GetBool(),
		DemoModeEnabled:        config.ServiceDemoMode.GetBool(),
		WebhooksEnabled:        config.WebhooksEnabled.GetBool(),
		PublicTeamsEnabled:     config.ServiceEnablePublicTeams.GetBool(),
		AllowIconChanges:       config.ServiceAllowIconChanges.GetBool(),
		EnabledProFeatures:     license.EnabledProFeatures(),
		AvailableMigrators: []string{
			(&vikunja_file.FileMigrator{}).Name(),
			(&ticktick.Migrator{}).Name(),
			(&wekan.Migrator{}).Name(),
			(&csvmigrator.Migrator{}).Name(),
		},
		Legal: LegalInfo{
			ImprintURL:       config.LegalImprintURL.GetString(),
			PrivacyPolicyURL: config.LegalPrivacyURL.GetString(),
		},
		AuthInfo: AuthInfo{
			Local: LocalAuthInfo{
				Enabled:             config.AuthLocalEnabled.GetBool(),
				RegistrationEnabled: config.AuthLocalEnabled.GetBool() && config.ServiceEnableRegistration.GetBool(),
			},
			Ldap: LdapAuthInfo{
				Enabled: config.AuthLdapEnabled.GetBool(),
			},
			OpenIDConnect: OpenIDAuthInfo{
				Enabled: config.AuthOpenIDEnabled.GetBool(),
			},
		},
	}

	providers, err := openid.GetAllProviders()
	if err != nil {
		log.Errorf("Error while getting openid providers for /info: %s", err)
		// No return here to not break /info
	}
	info.AuthInfo.OpenIDConnect.Providers = providers

	if config.MigrationTodoistEnable.GetBool() {
		m := &todoist.Migration{}
		info.AvailableMigrators = append(info.AvailableMigrators, m.Name())
	}
	if config.MigrationTrelloEnable.GetBool() {
		m := &trello.Migration{}
		info.AvailableMigrators = append(info.AvailableMigrators, m.Name())
	}
	if config.MigrationMicrosoftTodoEnable.GetBool() {
		m := &microsofttodo.Migration{}
		info.AvailableMigrators = append(info.AvailableMigrators, m.Name())
	}

	if config.BackgroundsEnabled.GetBool() {
		if config.BackgroundsUploadEnabled.GetBool() {
			info.EnabledBackgroundProviders = append(info.EnabledBackgroundProviders, "upload")
		}
		if config.BackgroundsUnsplashEnabled.GetBool() {
			info.EnabledBackgroundProviders = append(info.EnabledBackgroundProviders, "unsplash")
		}
	}

	return info
}