/*
This file is part of GNU Taler
(C) 2020 Taler Systems S.A.
GNU Taler is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
GNU Taler 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 General Public License for more details.
You should have received a copy of the GNU General Public License along with
GNU Taler; see the file COPYING. If not, see
*/
/**
* Utilities to handle Taler-style configuration files.
*
* @author Florian Dold
*/
/**
* Imports
*/
import { AmountJson } from "./amounts.js";
import { Amounts } from "./amounts.js";
const nodejs_fs = (function () {
let fs: typeof import("fs");
return function() {
if (!fs) {
/**
* need to use an expression when doing a require if we want
* webpack not to find out about the requirement
*/
const _r = "require"
fs = module[_r]("fs")
}
return fs
}
})()
export class ConfigError extends Error {
constructor(message: string) {
super();
Object.setPrototypeOf(this, ConfigError.prototype);
this.name = "ConfigError";
this.message = message;
}
}
type OptionMap = { [optionName: string]: string };
type SectionMap = { [sectionName: string]: OptionMap };
export class ConfigValue {
constructor(
private sectionName: string,
private optionName: string,
private val: string | undefined,
private converter: (x: string) => T,
) {}
required(): T {
if (!this.val) {
throw new ConfigError(
`required option [${this.sectionName}]/${this.optionName} not found`,
);
}
return this.converter(this.val);
}
orUndefined(): T | undefined {
if (this.val !== undefined) {
return this.converter(this.val);
} else {
return undefined;
}
}
orDefault(v: T): T | undefined {
if (this.val !== undefined) {
return this.converter(this.val);
} else {
return v;
}
}
isDefined(): boolean {
return this.val !== undefined;
}
}
/**
* Shell-style path substitution.
*
* Supported patterns:
* "$x" (look up "x")
* "${x}" (look up "x")
* "${x:-y}" (look up "x", fall back to expanded y)
*/
export function pathsub(
x: string,
lookup: (s: string, depth: number) => string | undefined,
depth = 0,
): string {
if (depth >= 10) {
throw Error("recursion in path substitution");
}
let s = x;
let l = 0;
while (l < s.length) {
if (s[l] === "$") {
if (s[l + 1] === "{") {
let depth = 1;
const start = l;
let p = start + 2;
let insideNamePart = true;
let hasDefault = false;
for (; p < s.length; p++) {
if (s[p] == "}") {
insideNamePart = false;
depth--;
} else if (s[p] === "$" && s[p + 1] === "{") {
insideNamePart = false;
depth++;
}
if (insideNamePart && s[p] === ":" && s[p + 1] === "-") {
hasDefault = true;
}
if (depth == 0) {
break;
}
}
if (depth == 0) {
const inner = s.slice(start + 2, p);
let varname: string;
let defaultValue: string | undefined;
if (hasDefault) {
[varname, defaultValue] = inner.split(":-", 2);
} else {
varname = inner;
defaultValue = undefined;
}
const r = lookup(inner, depth + 1);
if (r !== undefined) {
s = s.substr(0, start) + r + s.substr(p + 1);
l = start + r.length;
continue;
} else if (defaultValue !== undefined) {
const resolvedDefault = pathsub(defaultValue, lookup, depth + 1);
s = s.substr(0, start) + resolvedDefault + s.substr(p + 1);
l = start + resolvedDefault.length;
continue;
}
}
l = p;
continue;
} else {
const m = /^[a-zA-Z-_][a-zA-Z0-9-_]*/.exec(s.substring(l + 1));
if (m && m[0]) {
const r = lookup(m[0], depth + 1);
if (r !== undefined) {
s = s.substr(0, l) + r + s.substr(l + 1 + m[0].length);
l = l + r.length;
continue;
}
}
}
}
l++;
}
return s;
}
export class Configuration {
private sectionMap: SectionMap = {};
loadFromString(s: string): void {
const reComment = /^\s*#.*$/;
const reSection = /^\s*\[\s*([^\]]*)\s*\]\s*$/;
const reParam = /^\s*([^=]+?)\s*=\s*(.*?)\s*$/;
const reEmptyLine = /^\s*$/;
let currentSection: string | undefined = undefined;
const lines = s.split("\n");
for (const line of lines) {
if (reEmptyLine.test(line)) {
continue;
}
if (reComment.test(line)) {
continue;
}
const secMatch = line.match(reSection);
if (secMatch) {
currentSection = secMatch[1];
continue;
}
if (currentSection === undefined) {
throw Error("invalid configuration, expected section header");
}
currentSection = currentSection.toUpperCase();
const paramMatch = line.match(reParam);
if (paramMatch) {
const optName = paramMatch[1].toUpperCase();
let val = paramMatch[2];
if (val.startsWith('"') && val.endsWith('"')) {
val = val.slice(1, val.length - 1);
}
const sec = this.sectionMap[currentSection] ?? {};
this.sectionMap[currentSection] = Object.assign(sec, {
[optName]: val,
});
continue;
}
throw Error(
"invalid configuration, expected section header or option assignment",
);
}
}
setString(section: string, option: string, value: string): void {
const secNorm = section.toUpperCase();
const sec = this.sectionMap[secNorm] ?? (this.sectionMap[secNorm] = {});
sec[option.toUpperCase()] = value;
}
/**
* Get lower-cased section names.
*/
getSectionNames(): string[] {
return Object.keys(this.sectionMap).map((x) => x.toLowerCase());
}
getString(section: string, option: string): ConfigValue {
const secNorm = section.toUpperCase();
const optNorm = option.toUpperCase();
const val = (this.sectionMap[secNorm] ?? {})[optNorm];
return new ConfigValue(secNorm, optNorm, val, (x) => x);
}
getPath(section: string, option: string): ConfigValue {
const secNorm = section.toUpperCase();
const optNorm = option.toUpperCase();
const val = (this.sectionMap[secNorm] ?? {})[optNorm];
return new ConfigValue(secNorm, optNorm, val, (x) =>
pathsub(x, (v, d) => this.lookupVariable(v, d + 1)),
);
}
getYesNo(section: string, option: string): ConfigValue {
const secNorm = section.toUpperCase();
const optNorm = option.toUpperCase();
const val = (this.sectionMap[secNorm] ?? {})[optNorm];
const convert = (x: string): boolean => {
x = x.toLowerCase();
if (x === "yes") {
return true;
} else if (x === "no") {
return false;
}
throw Error(
`invalid config value for [${secNorm}]/${optNorm}, expected yes/no`,
);
};
return new ConfigValue(secNorm, optNorm, val, convert);
}
getNumber(section: string, option: string): ConfigValue {
const secNorm = section.toUpperCase();
const optNorm = option.toUpperCase();
const val = (this.sectionMap[secNorm] ?? {})[optNorm];
const convert = (x: string): number => {
try {
return Number.parseInt(x, 10);
} catch (e) {
throw Error(
`invalid config value for [${secNorm}]/${optNorm}, expected number`,
);
}
};
return new ConfigValue(secNorm, optNorm, val, convert);
}
lookupVariable(x: string, depth: number = 0): string | undefined {
// We loop up options in PATHS in upper case, as option names
// are case insensitive
const val = (this.sectionMap["PATHS"] ?? {})[x.toUpperCase()];
if (val !== undefined) {
return pathsub(val, (v, d) => this.lookupVariable(v, d), depth);
}
// Environment variables can be case sensitive, respect that.
const envVal = process.env[x];
if (envVal !== undefined) {
return envVal;
}
return;
}
getAmount(section: string, option: string): ConfigValue {
const val = (this.sectionMap[section] ?? {})[option];
return new ConfigValue(section, option, val, (x) =>
Amounts.parseOrThrow(x),
);
}
static load(filename: string): Configuration {
const s = nodejs_fs().readFileSync(filename, "utf-8");
const cfg = new Configuration();
cfg.loadFromString(s);
return cfg;
}
write(filename: string): void {
let s = "";
for (const sectionName of Object.keys(this.sectionMap)) {
s += `[${sectionName}]\n`;
for (const optionName of Object.keys(
this.sectionMap[sectionName] ?? {},
)) {
const val = this.sectionMap[sectionName][optionName];
if (val !== undefined) {
s += `${optionName} = ${val}\n`;
}
}
s += "\n";
}
nodejs_fs().writeFileSync(filename, s);
}
}