#include "cli_rename_magic.hpp"
#include "cli_arg_parse.hpp"
#include "cli_format_table.hpp"

#include <cstdint>
#include <cstdio>
#include <cstring>
#include <filesystem>
#include <fstream>
#include <string>

namespace wowee {
namespace editor {
namespace cli {

namespace {

namespace fs = std::filesystem;

bool readMagic(const fs::path& path, char magic[4]) {
    std::ifstream is(path, std::ios::binary);
    if (!is) return false;
    is.read(magic, 4);
    return is.gcount() == 4;
}

int handleRename(int& i, int argc, char** argv) {
    std::string filePath = argv[++i];
    bool dryRun = false;
    bool force = false;
    while (i + 1 < argc) {
        std::string a = argv[i + 1];
        if (a == "--dry-run") { dryRun = true; ++i; }
        else if (a == "--force") { force = true; ++i; }
        else break;
    }
    fs::path src = filePath;
    if (!fs::exists(src) || !fs::is_regular_file(src)) {
        std::fprintf(stderr,
            "rename-by-magic: not a file: %s\n", filePath.c_str());
        return 1;
    }
    char magic[4];
    if (!readMagic(src, magic)) {
        std::fprintf(stderr,
            "rename-by-magic: cannot read 4-byte magic: %s\n",
            filePath.c_str());
        return 1;
    }
    const FormatMagicEntry* fmt = findFormatByMagic(magic);
    if (!fmt) {
        char magicStr[5] = {magic[0], magic[1], magic[2], magic[3], 0};
        std::fprintf(stderr,
            "rename-by-magic: unrecognized magic '%s' in %s\n",
            magicStr, filePath.c_str());
        return 1;
    }
    fs::path dst = src;
    dst.replace_extension(fmt->extension);
    if (src == dst) {
        std::printf("rename-by-magic: %s already has correct "
                     "extension (%s) — no change\n",
                     filePath.c_str(), fmt->extension);
        return 0;
    }
    if (fs::exists(dst) && !force) {
        std::fprintf(stderr,
            "rename-by-magic: target %s already exists "
            "(pass --force to overwrite)\n", dst.string().c_str());
        return 1;
    }
    if (dryRun) {
        std::printf("rename-by-magic (dry-run): %s -> %s\n",
                     filePath.c_str(), dst.string().c_str());
        return 0;
    }
    std::error_code ec;
    fs::rename(src, dst, ec);
    if (ec) {
        std::fprintf(stderr,
            "rename-by-magic: rename failed: %s\n",
            ec.message().c_str());
        return 1;
    }
    std::printf("rename-by-magic: %s -> %s\n",
                 filePath.c_str(), dst.string().c_str());
    return 0;
}

} // namespace

bool handleRenameMagic(int& i, int argc, char** argv, int& outRc) {
    if (std::strcmp(argv[i], "--rename-by-magic") == 0 && i + 1 < argc) {
        outRc = handleRename(i, argc, argv); return true;
    }
    return false;
}

} // namespace cli
} // namespace editor
} // namespace wowee