web.v

1//! The web backend: read-only access to a public Koh mirror.2module remote34import net.http5import net.urllib67pub struct Web {8pub mut:9	base string10}1112pub fn new_web(base string) !Web {13	return Web{ base: kepr_host(base)! }14}1516pub fn kepr_host(value string) !string {17	for letter in value {18		if letter <= ` ` {19			return error('"${value}" is not a Kepr address — try kepr.uk')20		}21	}22	text := if value.starts_with('http://') || value.starts_with('https://') {23		value24	} else {25		'https://${value}'26	}27	parsed := urllib.parse(text) or { return error('"${value}" is not a Kepr address — try kepr.uk') }28	if parsed.scheme !in ['http', 'https'] || parsed.host == '' || parsed.path.trim_right('/') != '' || parsed.raw_query != '' || parsed.fragment != '' {29		return error('"${value}" is not a Kepr address — try kepr.uk')30	}31	if text.all_after('//').contains('@') {32		return error('"${value}" is not a Kepr address — try kepr.uk')33	}34	// `/api/connect` answers with the bucket's secret key, so plain http is only for a Kepr on35	// this machine: a test, or a local run.36	if parsed.scheme == 'http' && parsed.hostname().to_lower() !in ['127.0.0.1', 'localhost', '::1'] {37		return error('"${value}" needs https — plain http is only for a Kepr on this machine')38	}39	// A hostname is case-insensitive, so the stored form is the lower-case one.40	return '${parsed.scheme}://${parsed.host.to_lower()}'41}4243pub fn (mut w Web) get(key string) !Object {44	response := http.fetch(45		url:            w.url(key)46		method:         .get47		enable_http2:   false48		allow_redirect: false49	)!50	if response.status_code == 404 {51		return Object{}52	}53	if response.status_code < 200 || response.status_code >= 300 {54		return error('web GET ${key} failed: ${response.status_code}')55	}56	return Object{ found: true, body: response.body.bytes(), tag: response.header.get_custom('etag', http.HeaderQueryConfig{}) or { '' } }57}5859pub fn (mut w Web) list(prefix string) ![]string {60	response := http.fetch(61		url:            w.url(prefix)62		method:         .get63		enable_http2:   false64		allow_redirect: false65	)!66	if response.status_code == 404 {67		return []string{}68	}69	if response.status_code < 200 || response.status_code >= 300 {70		return error('web GET ${prefix} failed: ${response.status_code}')71	}72	mut result := []string{}73	for id in response.body.split_into_lines() {74		if id.trim_space() != '' { result << '${prefix}/${id.trim_space()}' }75	}76	return result77}7879pub fn (mut w Web) put_if_absent(key string, body []u8) !bool {80	return error('${w.repo(key)} is read-only.')81}8283pub fn (mut w Web) put_if_match(key string, body []u8, tag string) !bool {84	return error('${w.repo(key)} is read-only.')85}8687pub fn (mut w Web) delete(key string) ! {88	return error('${w.repo(key)} is read-only.')89}9091fn (w &Web) url(key string) string {92	parts := key.split('/')93	return '${w.base}/${parts[0]}/koh/${parts[1..].join('/')}'94}9596fn (w &Web) repo(key string) string {97	return '${w.base}/${key.all_before('/')}'98}