//! Machine-wide remote settings.
//!
//! Everything machine-specific lives in `~/.config/koh/`, never inside a repo:
//! one remote per machine, and the S3 keys in a file only the user can read.
//! The format is plain `key=value` lines so it can be read and edited by hand.

module machine

import os

pub const remote_file = 'remote'
pub const credentials_file = 'credentials'

pub const kind_folder = 'folder'
pub const kind_s3 = 's3'

pub struct RemoteSettings {
pub:
	kind     string
	path     string // folder backend
	endpoint string // s3 backend
	bucket   string
	region   string
}

pub struct Credentials {
pub:
	access_key string
	secret_key string
}

pub fn save_remote(settings RemoteSettings) ! {
	os.mkdir_all(config_dir(), os.MkdirParams{})!
	mut text := '# written by koh remote — the remote for every repo on this machine\n'
	text += 'kind=${settings.kind}\n'
	if settings.kind == kind_folder {
		text += 'path=${settings.path}\n'
	} else {
		text += 'endpoint=${settings.endpoint}\n'
		text += 'bucket=${settings.bucket}\n'
		text += 'region=${settings.region}\n'
	}
	os.write_file(config_path(remote_file), text)!
}

pub fn load_remote() !RemoteSettings {
	text := os.read_file(config_path(remote_file)) or {
		return error('this machine has no remote yet — run "koh remote"')
	}
	values := parse_config(text)
	settings := RemoteSettings{
		kind:     values['kind'] or { '' }
		path:     values['path'] or { '' }
		endpoint: values['endpoint'] or { '' }
		bucket:   values['bucket'] or { '' }
		region:   values['region'] or { '' }
	}
	if settings.kind !in [kind_folder, kind_s3] {
		return error('the remote setting in ${config_path(remote_file)} is not readable — run "koh remote" again')
	}
	return settings
}

pub fn has_remote() bool {
	return os.is_file(config_path(remote_file))
}

pub fn forget_remote() ! {
	if os.exists(config_path(remote_file)) {
		os.rm(config_path(remote_file))!
	}
}

// save_credentials writes the keys so that only the user can read them.
pub fn save_credentials(credentials Credentials) ! {
	os.mkdir_all(config_dir(), os.MkdirParams{})!
	mut text := '# written by koh remote — keep this file private\n'
	text += 'access_key=${credentials.access_key}\n'
	text += 'secret_key=${credentials.secret_key}\n'
	path := config_path(credentials_file)
	os.write_file(path, text)!
	os.chmod(path, 0o600)!
}

pub fn load_credentials() !Credentials {
	text := os.read_file(config_path(credentials_file)) or {
		return error('this machine has no S3 keys yet — run "koh remote"')
	}
	values := parse_config(text)
	credentials := Credentials{
		access_key: values['access_key'] or { '' }
		secret_key: values['secret_key'] or { '' }
	}
	if credentials.access_key == '' || credentials.secret_key == '' {
		return error('the S3 keys in ${config_path(credentials_file)} are incomplete — run "koh remote" again')
	}
	return credentials
}

fn parse_config(text string) map[string]string {
	mut values := map[string]string{}
	for line in text.split_into_lines() {
		trimmed := line.trim_space()
		if trimmed == '' || trimmed.starts_with('#') {
			continue
		}
		at := trimmed.index('=') or { continue }
		values[trimmed[..at].trim_space()] = trimmed[at + 1..].trim_space()
	}
	return values
}