import * as _ from "lodash";
import * as fs from "fs";
import * as scanner from "../scanner";
import * as yaml from "js-yaml";
import * as yargs from "yargs";

export var command = "extract";
export var describe = "Extracts a YAML from a list of files";

export function builder(yargs: yargs.Arguments) {
    return yargs
        .help("help")

        .option("list", {
            type: "boolean",
            default: true,
            describe:
                "Extract the data as a list of files, otherwise as a single file",
        })
        .option("output", {
            alias: "o",
            default: "-",
            describe: "Write output to a file or `-` for standard out",
        })
        .option("yaml", {
            alias: "y",
            type: "boolean",
            default: false,
            describe: "Extract the output as YAML instead of JSON",
        })
        .option("content", {
            type: "string",
            describe: "Include the content as a property in the extracted data",
        })

        .demand(1);
}

export function handler(argv: any) {
    // Parse through the files and retrieve the metadata.
    var files = argv._.splice(1);
    var data: any = scanner.scanFiles(argv, files);

    // Figure out how to handle the content property.
    if (!argv.content) {
        // Remove the content from the parsed file.
        data.forEach((x) => delete x.__content);
    } else if (argv.content !== "__content") {
        // Rename the content property.
        data.forEach((x) => {
            x[argv.content] = x.__content;
            delete x.__content;
        });
    }

    // Determine if we are displaying a list of items. If we want a list, then
    // we wrap the data in another list (list of a list) so it writes out only
    // one item. Otherwise, we write out each one.
    const items = argv.list ? [data] : data;

    // Figure the output of the results (JSON or YAML).
    const output = argv.yaml
        ? items.map((x: any) => yaml.safeDump(x)).join("\n")
        : items.map((x: any) => JSON.stringify(x)).join("\n");

    // Figure out where to write.
    if (argv.output === "-") {
        console.log(output);
    } else {
        fs.writeFileSync(argv.output, Buffer.from(output, "utf-8"));
    }
}