// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"bufio"
	"context"
	"errors"
	"os"

	"github.com/jackc/pgx/v5/pgxpool"
	"go.lindenii.runxiyu.org/lindenii-common/scfg"
)

// config holds the global configuration used by this instance. There is
// currently no synchronization mechanism, so it must not be modified after
// request handlers are spawned.
var config struct {
	HTTP struct {
		Net          string `scfg:"net"`
		Addr         string `scfg:"addr"`
		CookieExpiry int    `scfg:"cookie_expiry"`
		Root         string `scfg:"root"`
		ReadTimeout  uint32 `scfg:"read_timeout"`
		WriteTimeout uint32 `scfg:"write_timeout"`
		IdleTimeout  uint32 `scfg:"idle_timeout"`
		ReverseProxy bool   `scfg:"reverse_proxy"`
	} `scfg:"http"`
	Hooks struct {
		Socket string `scfg:"socket"`
		Execs  string `scfg:"execs"`
	} `scfg:"hooks"`
	LMTP struct {
		Socket       string `scfg:"socket"`
		Domain       string `scfg:"domain"`
		MaxSize      int64  `scfg:"max_size"`
		WriteTimeout uint32 `scfg:"write_timeout"`
		ReadTimeout  uint32 `scfg:"read_timeout"`
	} `scfg:"lmtp"`
	Git struct {
		RepoDir string `scfg:"repo_dir"`

		Socket  string `scfg:"socket"`

	} `scfg:"git"`
	SSH struct {
		Net  string `scfg:"net"`
		Addr string `scfg:"addr"`
		Key  string `scfg:"key"`
		Root string `scfg:"root"`
	} `scfg:"ssh"`
	IRC struct {
		Net   string `scfg:"net"`
		Addr  string `scfg:"addr"`
		TLS   bool   `scfg:"tls"`
		SendQ uint   `scfg:"sendq"`
		Nick  string `scfg:"nick"`
		User  string `scfg:"user"`
		Gecos string `scfg:"gecos"`
	} `scfg:"irc"`
	General struct {
		Title string `scfg:"title"`
	} `scfg:"general"`
	DB struct {
		Type string `scfg:"type"`
		Conn string `scfg:"conn"`
	} `scfg:"db"`
}

// loadConfig loads a configuration file from the specified path and unmarshals
// it to the global [config] struct. This may race with concurrent reads from
// [config]; additional synchronization is necessary if the configuration is to
// be made reloadable.
//
// TODO: Currently, it returns an error when the user specifies any unknown
// configuration patterns, but silently ignores fields in the [config] struct
// that is not present in the user's configuration file. We would prefer the
// exact opposite behavior.
func loadConfig(path string) (err error) {
	var configFile *os.File
	if configFile, err = os.Open(path); err != nil {
		return err
	}
	defer configFile.Close()

	decoder := scfg.NewDecoder(bufio.NewReader(configFile))
	if err = decoder.Decode(&config); err != nil {
		return err
	}

	if config.DB.Type != "postgres" {
		return errors.New("unsupported database type")
	}

	if database, err = pgxpool.New(context.Background(), config.DB.Conn); err != nil {
		return err
	}

	globalData["forge_title"] = config.General.Title

	return nil
}

http {
	# What network transport should we listen on?
	# Examples: tcp tcp4 tcp6 unix
	net tcp

	# What address to listen on?
	# Examples for net tcp*: 127.0.0.1:8080 :80
	# Example for unix: /var/run/lindenii/forge/http.sock
	addr /var/run/lindenii/forge/http.sock

	# How many seconds should cookies be remembered before they are purged?
	cookie_expiry 604800

	# What is the canonical URL of the web root?
	root https://forge.example.org

	# General HTTP server context timeout settings. It's recommended to
	# set them slightly higher than usual as Git operations over large
	# repos may take a long time.
	read_timeout 120
	write_timeout 1800
	idle_timeout 120

	# Are we running behind a reverse proxy? If so, we will trust
	# X-Forwarded-For headers.
	reverse_proxy true
}

irc {
	tls true
	net tcp
	addr irc.runxiyu.org:6697
	sendq 6000
	nick forge-test
	user forge
	gecos "Lindenii Forge Test"
}

git {

	# Where should newly-created Git repositories be stored?

	repo_dir /var/lib/lindenii/forge/repos

	# Where should git2d listen on?
	socket /var/run/lindenii/forge/git2d.sock

}

ssh {
	# What network transport should we listen on?
	# This should be "tcp" in almost all cases.
	net tcp

	# What address to listen on?
	addr :22

	# What is the path to the SSH host key? Generate it with ssh-keygen.
	# The key must have an empty password.
	key /etc/lindenii/ssh_host_ed25519_key

	# What is the canonical SSH URL?
	root ssh://forge.example.org
}

general {
	title "Test Forge"
}

db {
	# What type of database are we connecting to?
	# Currently only "postgres" is supported.
	type postgres

	# What is the connection string?
	conn postgresql:///lindenii-forge?host=/var/run/postgresql
}

hooks {
	# On which UNIX domain socket should we listen for hook callbacks on?
	socket /var/run/lindenii/forge/hooks.sock

	# Where should hook executables be put?
	execs /usr/libexec/lindenii/forge/hooks
}

lmtp {
	# On which UNIX domain socket should we listen for LMTP on?
	socket /var/run/lindenii/forge/lmtp.sock

	# What's the maximum acceptable message size?
	max_size 1000000

	# What is our domainpart?
	domain forge.example.org

	# General timeouts
	read_timeout 300
	write_timeout 300
}

.\" SPDX-License-Identifier: AGPL-3.0-only
.\" SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>
.Dd March 30, 2025
.Dt LINDENII-FORGE 5
.Os Lindenii Forge
.Sh NAME
.Nm lindenii-forge.scfg
.Nd configuration file for Lindenii Forge
.Sh DESCRIPTION
.Nm
describes the configuration for
.Xr lindenii-forge 1
instance using the
scfg
format.
.Pp
Each directive consists of a name followed by zero or more parameters. Directives may also introduce blocks of subdirectives using braces.
.Pp
Comments begin with
.Sq #
and extend to the end of the line.
.Sh DIRECTIVES
.Bl -tag -width Ds
.It Ic http
Configures the ingress HTTP server.
.Bl -tag -width Ds
.It Ic net
Network type to listen on (e.g., 
.Dq tcp ,
.Dq tcp4 ,
.Dq unix ) .
.It Ic addr
Address to listen on (e.g., 
.Dq :8080
or
.Dq /var/run/lindenii/forge/http.sock ) .
.It Ic cookie_expiry
How long (in seconds) to keep session cookies.
.It Ic root
Canonical root URL of the web interface (e.g.,
.Dq https://forge.example.org ) .
.It Ic read_timeout , write_timeout , idle_timeout
Timeouts, in seconds, for the general HTTP server context.
.It Ic reverse_proxy
Boolean indicating whether to trust X-Forwarded-For headers.
.El
.It Ic ssh
Configures the SSH server.
.Bl -tag -width Ds
.It Ic net
Network type to listen on
.Dq ( tcp
is recommended).
.It Ic addr
Address to listen on (e.g.,
.Dq :22 ) .
.It Ic key
Path to the SSH host key (must be passwordless).
.It Ic root
Canonical SSH URL prefix (e.g.,
.Dq ssh://forge.example.org ) .
.El
.It Ic git
Configures Git repository storage.
.Bl -tag -width Ds
.It Ic repo_dir
Filesystem path under which new repositories are stored.

.It Ic socket
Filesystem path for the socket listened on by
.Xr lindenii-forge-git2d 1

.El
.It Ic db
Configures database connection.
.Bl -tag -width Ds
.It Ic type
Database type (currently must be
.Dq postgres ) .
.It Ic conn
Connection string, e.g.,
.Dq postgresql:///lindenii-forge?host=/var/run/postgresql .
.El
.It Ic general
Miscellaneous settings.
.Bl -tag -width Ds
.It Ic title
A user-facing name for the instance.
.El
.It Ic hooks
Configures Git hook communication with the forge daemon.
.Bl -tag -width Ds
.It Ic socket
Path to a UNIX domain socket for receiving hook events.
.It Ic execs
Directory where Git hook executables are stored.
.El
.It Ic irc
Optional configuration for IRC presence.
.Bl -tag -width Ds
.It Ic tls
Boolean indicating whether to use TLS.
.It Ic net , addr
Network type and address (e.g.,
.Dq tcp ,
.Dq irc.example.org:6697 ) .
.It Ic sendq
Maximum send queue size.
.It Ic nick , user , gecos
Identity fields for the IRC connection.
.El
.It Ic lmtp
Configuration for the LMTP/MX component. You may wish to refer to
.Xr forge-mail 5
for information on configuring your SMTP server.
.Bl -tag -width Ds
.It Ic socket
The path to the UNIX domain socket to listen on.
.It Ic max_size
The maximum acceptable ingress message size.
.It Ic domain
The domain-part of our LMTP server.
.It Ic read_timeout , write_timeout
General timeouts for LMTP connections.
.El
.El
.Sh FILES
.Bl -tag -width Ds
.It Pa /etc/lindenii/forge.scfg
Default path to the configuration file.
.El
.Sh SEE ALSO
.Xr lindenii-forge 1 ,
.Xr lindenii-forge-hookc 1 ,
.Lk https://git.sr.ht/~emersion/scfg scfg
.Sh AUTHORS
.An Runxi Yu Aq Mt https://runxiyu.org
.An Test_User Aq Mt hax@runxiyu.org