import { parse } from "https://deno.land/std/flags/mod.ts";
import { walkSync} from "https://deno.land/std/fs/mod.ts";
import { createHash } from "https://deno.land/std/hash/mod.ts";

const MAX_SIZE = Math.pow(2, 29);

function getMD5(content) {
    return createHash("md5").update(content).toString();
}

function main () {
    const {
        _: folders,
        delete: deleteDuplicates = false,
    } = parse(Deno.args, { alias: {'d': 'delete'}});

    const folderList = folders.reduce((acc, folder) => {
        const fileInfo = Deno.statSync(folder);

        if (fileInfo.isDirectory) {
            acc.push(folder);
        }

        return acc;
    }, []);

    const filesToCheck = folderList.reduce((acc, folder) => {
        for (const entry of walkSync(folder)) {
            const stat = Deno.statSync(entry.path);

            if (entry.isFile && !acc.includes(entry.path) && stat.size < MAX_SIZE) {
                acc.push(entry.path);
            }
        }
        
        return acc;
    }, []);

    const checksumDict = filesToCheck.reduce((acc, file) => {
        const content = Deno.readTextFileSync(file);
        const md5 = getMD5(content);

        if (!acc[md5]) {
            acc[md5] = [];
        } else {
            acc[md5].push(file);
        }

        return acc;
    }, {})

    let foundDuplicates = false;

    for (const [checksum, files] of Object.entries(checksumDict)) {
        const duplicates = files.length;

        if (duplicates > 0) {
            foundDuplicates = true;

            console.info(`${duplicates} duplicate files found: ${['', ...files].join('\n  * ')}`);

            if (deleteDuplicates) {
                files.map(file => {
                    console.info(`Deleting file: ${file}`);
                    Deno.removeSync(file);
                })
            }
        }
    }

    if (!foundDuplicates) {
        console.info(`No duplicates found in ${folderList}`);
    }
}

main();