module main;

import std.stdio, std.file, std.path, std.algorithm;

enum EqualBy {
    Size, Name
}

int main(string[] argv)
{
    string[] dirs;
    EqualBy equality = EqualBy.Size;

    foreach(int i, string arg; argv) {
        if (i == 0) continue;// skip program name
        switch(arg)
        {
        case `-s`: equality = EqualBy.Size; break;
        case `-n`: equality = EqualBy.Name; break;
        case `?`: PrintUsage(argv[0]); return 0;
        default: dirs ~= arg; break;
        }
    }

    FileInfo[][] files; files.length = dirs.length;
    // assemble all files in all specified directories
    foreach(int i, string dir; dirs) {
        foreach (string name; dirEntries(dir, SpanMode.breadth))
        {
            if (isDir(name)) continue;
            files[i] ~= FileInfo(basename(name), name, getSize(name));
        }
    }
    // find similar files from the first dir in another dirs
    foreach(FileInfo fi; files[0]) {
        for(int i=1; i < files.length; i++) {
            foreach(FileInfo fi2; files[i]) {
                if (fi.fullName == fi2.fullName) continue;
                if (endsWith(fi.name, ".db") || endsWith(fi.name, ".BUP") || endsWith(fi.name, ".IFO") || endsWith(fi.name, ".VOB")) continue;// skip DVD files

                if((equality == EqualBy.Size && (fi.size == fi2.size)) ||
                   (equality == EqualBy.Name && (fi.name == fi2.name)))
                {
                    writeln(`EQ1: ` ~ fi.fullName);
                    writeln(`EQ2: ` ~ fi2.fullName);
                    writeln();
                }
            }
        }
    }

    return 0;
}

void PrintUsage(string programName)
{
    writeln("Find duplicates utility. Usage:\n" ~ programName ~ ` [options] Dir1 Dir2 ...` ~
`
Options:
-s : treat equality by size (default)
-n : -//- by name
`);
}

struct FileInfo
{
    string name;
    string fullName;
    ulong size;
}