let {readdirSync, readFileSync} = require("fs")

let files = Object.create(null)

for (let name of readdirSync(".")) {

let m = /^\d\d_(.*?)\.md$/.exec(name)

if (m) files[m[1]] = readFileSync(name, "utf8")

}

files.fast = files.hints = ""

let fail = 0

function error(file, msg) {

console.error(file + ": " + msg)

fail = 1

}

let link = /\]\(([\w_]+)(?:#([\w_]+))?\)/g, m

for (let file in files) {

while (m = link.exec(files[file])) {

let [_, file, anchor] = m

let target = files[file]

if (target == null)

error(file, "Unknown target file: " + file)

else if (anchor && target.indexOf("{{id " + anchor + "}}") == -1)

error(file, "Non-existing anchor: " + file + "#" + anchor)

}

}

process.exit(fail)