main.cpp

#include <iostream>
#include <string>
#include <cstring>
#include <cstdint>
#include <iomanip>
#include "Huffman.h"
#include "FileHandler.h"
#include "utils.h"

static void printUsage(const char* prog) {
    std::cout << "Usage:\n"
              << "  " << prog << " compress   <input_file>      <output.bin>\n"
              << "  " << prog << " decompress <input.bin>       <output_file>\n"
              << "  " << prog << " info       <input.bin>\n";
}

int main(int argc, char* argv[]) {
    if (argc < 3) { printUsage(argv[0]); return 1; }

    std::string cmd = argv[1];

    // ── COMPRESS ────────────────────────────────────────────────
    if (cmd == "compress") {
        if (argc < 4) { printUsage(argv[0]); return 1; }
        std::string inPath  = argv[2];
        std::string outPath = argv[3];

        std::cout << "[+] Reading: " << inPath << "\n";
        std::string text = FileHandler::readFile(inPath);
        std::cout << "[+] File size: " << text.size() << " bytes, "
                  << "unique chars: ";

        // Build Huffman tree
        Huffman huff;
        huff.build(text);
        std::cout << huff.codes().size() << "\n";

        // Encode
        std::string bits     = huff.encode(text);
        std::string treeData = huff.serializeTree();

        // Write compressed file
        FileHandler::writeCompressed(outPath, treeData, bits, (uint32_t)text.size());

        // Stats
        Utils::Stats stats = Utils::computeStats(text, bits, huff.codes());
        Utils::printStats(stats);
        Utils::printCodes(huff.codes());

        std::cout << "[✓] Compressed → " << outPath << "\n";

    // ── DECOMPRESS ──────────────────────────────────────────────
    } else if (cmd == "decompress") {
        if (argc < 4) { printUsage(argv[0]); return 1; }
        std::string inPath  = argv[2];
        std::string outPath = argv[3];

        std::cout << "[+] Reading: " << inPath << "\n";

        std::string treeData, bits;
        uint32_t originalSize = 0;
        FileHandler::readCompressed(inPath, treeData, bits, originalSize);

        // Rebuild tree
        Huffman huff;
        size_t pos = 0;
        huff.deserializeTree(treeData, pos);

        // Decode
        std::string result = huff.decode(bits);

        // Verify size
        if (result.size() != originalSize) {
            std::cerr << "[!] Warning: decoded size (" << result.size()
                      << ") != expected (" << originalSize << ")\n";
        }

        FileHandler::writeFile(outPath, result);
        std::cout << "[✓] Decompressed → " << outPath
                  << "  (" << result.size() << " bytes)\n";

    // ── INFO ────────────────────────────────────────────────────
    } else if (cmd == "info") {
        std::string inPath = argv[2];
        std::string treeData, bits;
        uint32_t originalSize = 0;
        FileHandler::readCompressed(inPath, treeData, bits, originalSize);

        Huffman huff;
        size_t pos = 0;
        huff.deserializeTree(treeData, pos);

        size_t compressedBytes = (bits.size() + 7) / 8;
        double ratio = (double)compressedBytes / originalSize;

        std::cout << "\n--- File Info: " << inPath << " ---\n";
        std::cout << "  Original size    : " << originalSize     << " bytes\n";
        std::cout << "  Compressed size  : " << compressedBytes  << " bytes\n";
        std::cout << "  Compression ratio: " << std::fixed << std::setprecision(2) << ratio << "\n";
        std::cout << "  Space saving     : " << (1.0 - ratio) * 100.0 << "%\n";
        std::cout << "  Unique chars     : " << huff.codes().size() << "\n\n";
        Utils::printCodes(huff.codes());

    } else {
        std::cerr << "Unknown command: " << cmd << "\n";
        printUsage(argv[0]);
        return 1;
    }

    return 0;
}