// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// 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 <http://www.gnu.org/licenses/>.

package config

import (
	"reflect"
	"time"

	"codeberg.org/gruf/go-bytesize"
	"github.com/mitchellh/mapstructure"
)

// cfgtype is the reflected type information of Configuration{}.
var cfgtype = reflect.TypeOf(Configuration{})

// fieldtag will fetch the string value for the given tag name
// on the given field name in the Configuration{} struct.
func fieldtag(field, tag string) string {
	sfield, ok := cfgtype.FieldByName(field)
	if !ok {
		panic("unknown struct field")
	}
	return sfield.Tag.Get(tag)
}

// Configuration represents global GTS server runtime configuration.
//
// Please note that if you update this struct's fields or tags, you
// will need to regenerate the global Getter/Setter helpers by running:
// `go run ./internal/config/gen/ -out ./internal/config/helpers.gen.go`
type Configuration struct {
	LogLevel        string   `name:"log-level" usage:"Log level to run at: [trace, debug, info, warn, fatal]"`
	LogDbQueries    bool     `name:"log-db-queries" usage:"Log database queries verbosely when log-level is trace or debug"`
	ApplicationName string   `name:"application-name" usage:"Name of the application, used in various places internally"`
	LandingPageUser string   `name:"landing-page-user" usage:"the user that should be shown on the instance's landing page"`
	ConfigPath      string   `name:"config-path" usage:"Path to a file containing gotosocial configuration. Values set in this file will be overwritten by values set as env vars or arguments"`
	Host            string   `name:"host" usage:"Hostname to use for the server (eg., example.org, gotosocial.whatever.com). DO NOT change this on a server that's already run!"`
	AccountDomain   string   `name:"account-domain" usage:"Domain to use in account names (eg., example.org, whatever.com). If not set, will default to the setting for host. DO NOT change this on a server that's already run!"`
	Protocol        string   `name:"protocol" usage:"Protocol to use for the REST api of the server (only use http if you are debugging or behind a reverse proxy!)"`
	BindAddress     string   `name:"bind-address" usage:"Bind address to use for the GoToSocial server (eg., 0.0.0.0, 172.138.0.9, [::], localhost). For ipv6, enclose the address in square brackets, eg [2001:db8::fed1]. Default binds to all interfaces."`
	Port            int      `name:"port" usage:"Port to use for GoToSocial. Change this to 443 if you're running the binary directly on the host machine."`
	TrustedProxies  []string `name:"trusted-proxies" usage:"Proxies to trust when parsing x-forwarded headers into real IPs."`
	SoftwareVersion string   `name:"software-version" usage:""`

	DbType                   string        `name:"db-type" usage:"Database type: eg., postgres"`
	DbAddress                string        `name:"db-address" usage:"Database ipv4 address, hostname, or filename"`
	DbPort                   int           `name:"db-port" usage:"Database port"`
	DbUser                   string        `name:"db-user" usage:"Database username"`
	DbPassword               string        `name:"db-password" usage:"Database password"`
	DbDatabase               string        `name:"db-database" usage:"Database name"`
	DbTLSMode                string        `name:"db-tls-mode" usage:"Database tls mode"`
	DbTLSCACert              string        `name:"db-tls-ca-cert" usage:"Path to CA cert for db tls connection"`
	DbMaxOpenConnsMultiplier int           `name:"db-max-open-conns-multiplier" usage:"Multiplier to use per cpu for max open database connections. 0 or less is normalized to 1."`
	DbSqliteJournalMode      string        `name:"db-sqlite-journal-mode" usage:"Sqlite only: see https://www.sqlite.org/pragma.html#pragma_journal_mode"`
	DbSqliteSynchronous      string        `name:"db-sqlite-synchronous" usage:"Sqlite only: see https://www.sqlite.org/pragma.html#pragma_synchronous"`
	DbSqliteCacheSize        bytesize.Size `name:"db-sqlite-cache-size" usage:"Sqlite only: see https://www.sqlite.org/pragma.html#pragma_cache_size"`
	DbSqliteBusyTimeout      time.Duration `name:"db-sqlite-busy-timeout" usage:"Sqlite only: see https://www.sqlite.org/pragma.html#pragma_busy_timeout"`

	WebTemplateBaseDir string `name:"web-template-base-dir" usage:"Basedir for html templating files for rendering pages and composing emails."`
	WebAssetBaseDir    string `name:"web-asset-base-dir" usage:"Directory to serve static assets from, accessible at example.org/assets/"`

	InstanceExposePeers            bool `name:"instance-expose-peers" usage:"Allow unauthenticated users to query /api/v1/instance/peers?filter=open"`
	InstanceExposeSuspended        bool `name:"instance-expose-suspended" usage:"Expose suspended instances via web UI, and allow unauthenticated users to query /api/v1/instance/peers?filter=suspended"`
	InstanceExposeSuspendedWeb     bool `name:"instance-expose-suspended-web" usage:"Expose list of suspended instances as webpage on /about/suspended"`
	InstanceExposePublicTimeline   bool `name:"instance-expose-public-timeline" usage:"Allow unauthenticated users to query /api/v1/timelines/public"`
	InstanceDeliverToSharedInboxes bool `name:"instance-deliver-to-shared-inboxes" usage:"Deliver federated messages to shared inboxes, if they're available."`

	AccountsRegistrationOpen bool `name:"accounts-registration-open" usage:"Allow anyone to submit an account signup request. If false, server will be invite-only."`
	AccountsApprovalRequired bool `name:"accounts-approval-required" usage:"Do account signups require approval by an admin or moderator before user can log in? If false, new registrations will be automatically approved."`
	AccountsReasonRequired   bool `name:"accounts-reason-required" usage:"Do new account signups require a reason to be submitted on registration?"`
	AccountsAllowCustomCSS   bool `name:"accounts-allow-custom-css" usage:"Allow accounts to enable custom CSS for their profile pages and statuses."`

	MediaImageMaxSize        bytesize.Size `name:"media-image-max-size" usage:"Max size of accepted images in bytes"`
	MediaVideoMaxSize        bytesize.Size `name:"media-video-max-size" usage:"Max size of accepted videos in bytes"`
	MediaDescriptionMinChars int           `name:"media-description-min-chars" usage:"Min required chars for an image description"`
	MediaDescriptionMaxChars int           `name:"media-description-max-chars" usage:"Max permitted chars for an image description"`
	MediaRemoteCacheDays     int           `name:"media-remote-cache-days" usage:"Number of days to locally cache media from remote instances. If set to 0, remote media will be kept indefinitely."`
	MediaEmojiLocalMaxSize   bytesize.Size `name:"media-emoji-local-max-size" usage:"Max size in bytes of emojis uploaded to this instance via the admin API."`
	MediaEmojiRemoteMaxSize  bytesize.Size `name:"media-emoji-remote-max-size" usage:"Max size in bytes of emojis to download from other instances."`

	StorageBackend       string `name:"storage-backend" usage:"Storage backend to use for media attachments"`
	StorageLocalBasePath string `name:"storage-local-base-path" usage:"Full path to an already-created directory where gts should store/retrieve media files. Subfolders will be created within this dir."`
	StorageS3Endpoint    string `name:"storage-s3-endpoint" usage:"S3 Endpoint URL (e.g 'minio.example.org:9000')"`
	StorageS3AccessKey   string `name:"storage-s3-access-key" usage:"S3 Access Key"`
	StorageS3SecretKey   string `name:"storage-s3-secret-key" usage:"S3 Secret Key"`
	StorageS3UseSSL      bool   `name:"storage-s3-use-ssl" usage:"Use SSL for S3 connections. Only set this to 'false' when testing locally"`
	StorageS3BucketName  string `name:"storage-s3-bucket" usage:"Place blobs in this bucket"`
	StorageS3Proxy       bool   `name:"storage-s3-proxy" usage:"Proxy S3 contents through GoToSocial instead of redirecting to a presigned URL"`

	StatusesMaxChars           int `name:"statuses-max-chars" usage:"Max permitted characters for posted statuses"`
	StatusesCWMaxChars         int `name:"statuses-cw-max-chars" usage:"Max permitted characters for content/spoiler warnings on statuses"`
	StatusesPollMaxOptions     int `name:"statuses-poll-max-options" usage:"Max amount of options permitted on a poll"`
	StatusesPollOptionMaxChars int `name:"statuses-poll-option-max-chars" usage:"Max amount of characters for a poll option"`
	StatusesMediaMaxFiles      int `name:"statuses-media-max-files" usage:"Maximum number of media files/attachments per status"`

	LetsEncryptEnabled      bool   `name:"letsencrypt-enabled" usage:"Enable letsencrypt TLS certs for this server. If set to true, then cert dir also needs to be set (or take the default)."`
	LetsEncryptPort         int    `name:"letsencrypt-port" usage:"Port to listen on for letsencrypt certificate challenges. Must not be the same as the GtS webserver/API port."`
	LetsEncryptCertDir      string `name:"letsencrypt-cert-dir" usage:"Directory to store acquired letsencrypt certificates."`
	LetsEncryptEmailAddress string `name:"letsencrypt-email-address" usage:"Email address to use when requesting letsencrypt certs. Will receive updates on cert expiry etc."`

	TLSCertificateChain string `name:"tls-certificate-chain" usage:"Filesystem path to the certificate chain including any intermediate CAs and the TLS public key"`
	TLSCertificateKey   string `name:"tls-certificate-key" usage:"Filesystem path to the TLS private key"`

	OIDCEnabled          bool     `name:"oidc-enabled" usage:"Enabled OIDC authorization for this instance. If set to true, then the other OIDC flags must also be set."`
	OIDCIdpName          string   `name:"oidc-idp-name" usage:"Name of the OIDC identity provider. Will be shown to the user when logging in."`
	OIDCSkipVerification bool     `name:"oidc-skip-verification" usage:"Skip verification of tokens returned by the OIDC provider. Should only be set to 'true' for testing purposes, never in a production environment!"`
	OIDCIssuer           string   `name:"oidc-issuer" usage:"Address of the OIDC issuer. Should be the web address, including protocol, at which the issuer can be reached. Eg., 'https://example.org/auth'"`
	OIDCClientID         string   `name:"oidc-client-id" usage:"ClientID of GoToSocial, as registered with the OIDC provider."`
	OIDCClientSecret     string   `name:"oidc-client-secret" usage:"ClientSecret of GoToSocial, as registered with the OIDC provider."`
	OIDCScopes           []string `name:"oidc-scopes" usage:"OIDC scopes."`
	OIDCLinkExisting     bool     `name:"oidc-link-existing" usage:"link existing user accounts to OIDC logins based on the stored email value"`
	OIDCAdminGroups      []string `name:"oidc-admin-groups" usage:"Membership of one of the listed groups makes someone a GtS admin"`

	SMTPHost               string `name:"smtp-host" usage:"Host of the smtp server. Eg., 'smtp.eu.mailgun.org'"`
	SMTPPort               int    `name:"smtp-port" usage:"Port of the smtp server. Eg., 587"`
	SMTPUsername           string `name:"smtp-username" usage:"Username to authenticate with the smtp server as. Eg., 'postmaster@mail.example.org'"`
	SMTPPassword           string `name:"smtp-password" usage:"Password to pass to the smtp server."`
	SMTPFrom               string `name:"smtp-from" usage:"Address to use as the 'from' field of the email. Eg., 'gotosocial@example.org'"`
	SMTPDiscloseRecipients bool   `name:"smtp-disclose-recipients" usage:"If true, email notifications sent to multiple recipients will be To'd to every recipient at once. If false, recipients will not be disclosed"`

	SyslogEnabled  bool   `name:"syslog-enabled" usage:"Enable the syslog logging hook. Logs will be mirrored to the configured destination."`
	SyslogProtocol string `name:"syslog-protocol" usage:"Protocol to use when directing logs to syslog. Leave empty to connect to local syslog."`
	SyslogAddress  string `name:"syslog-address" usage:"Address:port to send syslog logs to. Leave empty to connect to local syslog."`

	AdvancedCookiesSamesite      string        `name:"advanced-cookies-samesite" usage:"'strict' or 'lax', see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie/SameSite"`
	AdvancedRateLimitRequests    int           `name:"advanced-rate-limit-requests" usage:"Amount of HTTP requests to permit within a 5 minute window. 0 or less turns rate limiting off."`
	AdvancedThrottlingMultiplier int           `name:"advanced-throttling-multiplier" usage:"Multiplier to use per cpu for http request throttling. 0 or less turns throttling off."`
	AdvancedThrottlingRetryAfter time.Duration `name:"advanced-throttling-retry-after" usage:"Retry-After duration response to send for throttled requests."`

	// Cache configuration vars.
	Cache CacheConfiguration `name:"cache"`

	// TODO: move these elsewhere, these are more ephemeral vs long-running flags like above
	AdminAccountUsername  string `name:"username" usage:"the username to create/delete/etc"`
	AdminAccountEmail     string `name:"email" usage:"the email address of this account"`
	AdminAccountPassword  string `name:"password" usage:"the password to set for this account"`
	AdminTransPath        string `name:"path" usage:"the path of the file to import from/export to"`
	AdminMediaPruneDryRun bool   `name:"dry-run" usage:"perform a dry run and only log number of items eligible for pruning"`

	RequestIDHeader string `name:"request-id-header" usage:"Header to extract the Request ID from. Eg.,'X-Request-Id'"`
}

type CacheConfiguration struct {
	GTS GTSCacheConfiguration `name:"gts"`

	VisibilityMaxSize   int           `name:"visibility-max-size"`
	VisibilityTTL       time.Duration `name:"visibility-ttl"`
	VisibilitySweepFreq time.Duration `name:"visibility-sweep-freq"`
}

type GTSCacheConfiguration struct {
	AccountMaxSize   int           `name:"account-max-size"`
	AccountTTL       time.Duration `name:"account-ttl"`
	AccountSweepFreq time.Duration `name:"account-sweep-freq"`

	BlockMaxSize   int           `name:"block-max-size"`
	BlockTTL       time.Duration `name:"block-ttl"`
	BlockSweepFreq time.Duration `name:"block-sweep-freq"`

	DomainBlockMaxSize   int           `name:"domain-block-max-size"`
	DomainBlockTTL       time.Duration `name:"domain-block-ttl"`
	DomainBlockSweepFreq time.Duration `name:"domain-block-sweep-freq"`

	EmojiMaxSize   int           `name:"emoji-max-size"`
	EmojiTTL       time.Duration `name:"emoji-ttl"`
	EmojiSweepFreq time.Duration `name:"emoji-sweep-freq"`

	EmojiCategoryMaxSize   int           `name:"emoji-category-max-size"`
	EmojiCategoryTTL       time.Duration `name:"emoji-category-ttl"`
	EmojiCategorySweepFreq time.Duration `name:"emoji-category-sweep-freq"`

	FollowMaxSize   int           `name:"follow-max-size"`
	FollowTTL       time.Duration `name:"follow-ttl"`
	FollowSweepFreq time.Duration `name:"follow-sweep-freq"`

	FollowRequestMaxSize   int           `name:"follow-request-max-size"`
	FollowRequestTTL       time.Duration `name:"follow-request-ttl"`
	FollowRequestSweepFreq time.Duration `name:"follow-request-sweep-freq"`

	MediaMaxSize   int           `name:"media-max-size"`
	MediaTTL       time.Duration `name:"media-ttl"`
	MediaSweepFreq time.Duration `name:"media-sweep-freq"`

	MentionMaxSize   int           `name:"mention-max-size"`
	MentionTTL       time.Duration `name:"mention-ttl"`
	MentionSweepFreq time.Duration `name:"mention-sweep-freq"`

	NotificationMaxSize   int           `name:"notification-max-size"`
	NotificationTTL       time.Duration `name:"notification-ttl"`
	NotificationSweepFreq time.Duration `name:"notification-sweep-freq"`

	ReportMaxSize   int           `name:"report-max-size"`
	ReportTTL       time.Duration `name:"report-ttl"`
	ReportSweepFreq time.Duration `name:"report-sweep-freq"`

	StatusMaxSize   int           `name:"status-max-size"`
	StatusTTL       time.Duration `name:"status-ttl"`
	StatusSweepFreq time.Duration `name:"status-sweep-freq"`

	StatusFaveMaxSize   int           `name:"status-fave-max-size"`
	StatusFaveTTL       time.Duration `name:"status-fave-ttl"`
	StatusFaveSweepFreq time.Duration `name:"status-fave-sweep-freq"`

	TombstoneMaxSize   int           `name:"tombstone-max-size"`
	TombstoneTTL       time.Duration `name:"tombstone-ttl"`
	TombstoneSweepFreq time.Duration `name:"tombstone-sweep-freq"`

	UserMaxSize   int           `name:"user-max-size"`
	UserTTL       time.Duration `name:"user-ttl"`
	UserSweepFreq time.Duration `name:"user-sweep-freq"`

	WebfingerMaxSize   int           `name:"webfinger-max-size"`
	WebfingerTTL       time.Duration `name:"webfinger-ttl"`
	WebfingerSweepFreq time.Duration `name:"webfinger-sweep-freq"`
}

// MarshalMap will marshal current Configuration into a map structure (useful for JSON/TOML/YAML).
func (cfg *Configuration) MarshalMap() (map[string]interface{}, error) {
	var dst map[string]interface{}
	dec, _ := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
		TagName: "name",
		Result:  &dst,
	})
	if err := dec.Decode(cfg); err != nil {
		return nil, err
	}
	return dst, nil
}