module web

import net.urllib
import net.http

// Method attributes that should be ignored when parsing, as they're used
// elsewhere.
const attrs_to_ignore = ['auth']

// Parsing function attributes for methods and path.
fn parse_attrs(name string, attrs []string) ?([]http.Method, string) {
	if attrs.len == 0 {
		return [http.Method.get], '/$name'
	}

	mut x := attrs.clone()
	mut methods := []http.Method{}
	mut path := ''

	for i := 0; i < x.len; {
		attr := x[i]
		attru := attr.to_upper()
		m := http.method_from_str(attru)
		if attru == 'GET' || m != .get {
			methods << m
			x.delete(i)
			continue
		}
		if attr.starts_with('/') {
			if path != '' {
				return IError(http.MultiplePathAttributesError{})
			}
			path = attr
			x.delete(i)
			continue
		}
		i++
	}
	if x.len > 0 && x.any(!web.attrs_to_ignore.contains(it)) {
		return IError(http.UnexpectedExtraAttributeError{
			attributes: x
		})
	}
	if methods.len == 0 {
		methods = [http.Method.get]
	}
	if path == '' {
		path = '/$name'
	}
	// Make path lowercase for case-insensitive comparisons
	return methods, path.to_lower()
}

// Extracts query parameters from a URL.
fn parse_query_from_url(url urllib.URL) map[string]string {
	mut query := map[string]string{}
	for v in url.query().data {
		query[v.key] = v.value
	}
	return query
}

// Extract form data from an HTTP request.
fn parse_form_from_request(request http.Request) ?(map[string]string, map[string][]http.FileData) {
	mut form := map[string]string{}
	mut files := map[string][]http.FileData{}
	if request.method in methods_with_form {
		ct := request.header.get(.content_type) or { '' }.split(';').map(it.trim_left(' \t'))
		if 'multipart/form-data' in ct {
			boundary := ct.filter(it.starts_with('boundary='))
			if boundary.len != 1 {
				return error('detected more that one form-data boundary')
			}
			form, files = http.parse_multipart_form(request.data, boundary[0][9..])
		} else {
			form = http.parse_form(request.data)
		}
	}
	return form, files
}