#include "content_pack.hpp"
#include "core/logger.hpp"
#include <nlohmann/json.hpp>
#include <fstream>
#include <filesystem>
#include <cstring>

namespace wowee {
namespace editor {

// WCP file format (simple concatenated archive):
// Header: "WCP1" (4 bytes) + fileCount (4) + infoJsonSize (4)
// Info JSON block (infoJsonSize bytes)
// File table: for each file: pathLen(2) + path(pathLen) + dataSize(4)
// File data: concatenated file contents

static constexpr uint32_t WCP_MAGIC = 0x31504357; // "WCP1"

bool ContentPacker::packZone(const std::string& outputDir, const std::string& mapName,
                              const std::string& destPath, const ContentPackInfo& info) {
    namespace fs = std::filesystem;
    std::string srcDir = outputDir + "/" + mapName;

    if (!fs::exists(srcDir)) {
        LOG_ERROR("Source directory not found: ", srcDir);
        return false;
    }

    // Collect all files
    std::vector<std::pair<std::string, std::string>> files; // relative path, full path
    for (auto& entry : fs::recursive_directory_iterator(srcDir)) {
        if (!entry.is_regular_file()) continue;
        std::string rel = fs::relative(entry.path(), srcDir).string();
        files.push_back({rel, entry.path().string()});
    }

    if (files.empty()) {
        LOG_ERROR("No files to pack in: ", srcDir);
        return false;
    }

    // Build info JSON
    nlohmann::json infoObj;
    infoObj["format"] = info.format;
    infoObj["name"] = info.name;
    infoObj["author"] = info.author;
    infoObj["description"] = info.description;
    infoObj["version"] = info.version;
    infoObj["mapId"] = info.mapId;
    infoObj["fileCount"] = files.size();
    nlohmann::json fileArr = nlohmann::json::array();
    for (const auto& [rel, full] : files) {
        fileArr.push_back({{"path", rel}, {"size", fs::file_size(full)}});
    }
    infoObj["files"] = fileArr;
    std::string infoJson = infoObj.dump(2);

    // Write WCP file
    std::ofstream out(destPath, std::ios::binary);
    if (!out) {
        LOG_ERROR("Failed to create pack file: ", destPath);
        return false;
    }

    // Header
    out.write(reinterpret_cast<const char*>(&WCP_MAGIC), 4);
    uint32_t fileCount = static_cast<uint32_t>(files.size());
    out.write(reinterpret_cast<const char*>(&fileCount), 4);
    uint32_t infoSize = static_cast<uint32_t>(infoJson.size());
    out.write(reinterpret_cast<const char*>(&infoSize), 4);

    // Info JSON
    out.write(infoJson.data(), infoJson.size());

    // File table + data
    for (const auto& [rel, full] : files) {
        uint16_t pathLen = static_cast<uint16_t>(rel.size());
        out.write(reinterpret_cast<const char*>(&pathLen), 2);
        out.write(rel.data(), pathLen);

        std::ifstream fin(full, std::ios::binary | std::ios::ate);
        uint32_t dataSize = static_cast<uint32_t>(fin.tellg());
        fin.seekg(0);
        out.write(reinterpret_cast<const char*>(&dataSize), 4);

        std::vector<char> buf(dataSize);
        fin.read(buf.data(), dataSize);
        out.write(buf.data(), dataSize);
    }

    LOG_INFO("Content pack created: ", destPath, " (", files.size(), " files, ",
             out.tellp(), " bytes)");
    return true;
}

bool ContentPacker::unpackZone(const std::string& wcpPath, const std::string& destDir) {
    std::ifstream in(wcpPath, std::ios::binary);
    if (!in) return false;

    uint32_t magic;
    in.read(reinterpret_cast<char*>(&magic), 4);
    if (magic != WCP_MAGIC) {
        LOG_ERROR("Not a WCP file: ", wcpPath);
        return false;
    }

    uint32_t fileCount, infoSize;
    in.read(reinterpret_cast<char*>(&fileCount), 4);
    in.read(reinterpret_cast<char*>(&infoSize), 4);

    // Skip info JSON
    in.seekg(infoSize, std::ios::cur);

    namespace fs = std::filesystem;
    fs::create_directories(destDir);

    for (uint32_t i = 0; i < fileCount; i++) {
        uint16_t pathLen;
        in.read(reinterpret_cast<char*>(&pathLen), 2);
        std::string path(pathLen, '\0');
        in.read(path.data(), pathLen);

        uint32_t dataSize;
        in.read(reinterpret_cast<char*>(&dataSize), 4);

        std::vector<char> data(dataSize);
        in.read(data.data(), dataSize);

        std::string fullPath = destDir + "/" + path;
        fs::create_directories(fs::path(fullPath).parent_path());
        std::ofstream fout(fullPath, std::ios::binary);
        fout.write(data.data(), dataSize);
    }

    LOG_INFO("Content pack extracted to: ", destDir, " (", fileCount, " files)");
    return true;
}

bool ContentPacker::readInfo(const std::string& wcpPath, ContentPackInfo& info) {
    std::ifstream in(wcpPath, std::ios::binary);
    if (!in) return false;

    uint32_t magic;
    in.read(reinterpret_cast<char*>(&magic), 4);
    if (magic != WCP_MAGIC) return false;

    uint32_t fileCount, infoSize;
    in.read(reinterpret_cast<char*>(&fileCount), 4);
    in.read(reinterpret_cast<char*>(&infoSize), 4);

    std::string jsonStr(infoSize, '\0');
    in.read(jsonStr.data(), infoSize);

    try {
        auto j = nlohmann::json::parse(jsonStr);
        info.name = j.value("name", "");
        info.author = j.value("author", "");
        info.description = j.value("description", "");
        info.version = j.value("version", "");
        info.format = j.value("format", "");
        info.mapId = j.value("mapId", 9000u);
        info.files.clear();
        if (j.contains("files") && j["files"].is_array()) {
            for (const auto& jf : j["files"]) {
                ContentPackInfo::FileEntry fe;
                fe.path = jf.value("path", "");
                fe.size = jf.value("size", 0ULL);
                auto dot = fe.path.rfind('.');
                if (dot != std::string::npos) {
                    std::string ext = fe.path.substr(dot);
                    if (ext == ".wot" || ext == ".whm") fe.category = "terrain";
                    else if (ext == ".wom") fe.category = "model";
                    else if (ext == ".wob") fe.category = "building";
                    else if (ext == ".png") fe.category = "texture";
                    else if (ext == ".json") fe.category = "data";
                    else if (ext == ".adt" || ext == ".wdt") fe.category = "legacy";
                    else fe.category = "other";
                }
                info.files.push_back(fe);
            }
        }
    } catch (...) {
        return false;
    }

    return true;
}

static bool checkMagic(const std::string& path, uint32_t expectedMagic) {
    std::ifstream f(path, std::ios::binary);
    if (!f) return false;
    uint32_t magic = 0;
    f.read(reinterpret_cast<char*>(&magic), 4);
    return magic == expectedMagic;
}

ContentPacker::ValidationResult ContentPacker::validateZone(const std::string& zoneDir) {
    namespace fs = std::filesystem;
    ValidationResult r;
    if (!fs::exists(zoneDir)) return r;

    static constexpr uint32_t WHM_MAGIC = 0x314D4857; // "WHM1"
    static constexpr uint32_t WOM_MAGIC = 0x314D4F57; // "WOM1"
    static constexpr uint32_t WOB_MAGIC = 0x31424F57; // "WOB1"
    static constexpr uint32_t WOC_MAGIC = 0x31434F57; // "WOC1"

    for (auto& entry : fs::recursive_directory_iterator(zoneDir)) {
        if (!entry.is_regular_file()) continue;
        std::string ext = entry.path().extension().string();
        std::string fname = entry.path().filename().string();
        if (ext == ".wot") r.hasWot = true;
        if (ext == ".whm") {
            r.hasWhm = true;
            if (checkMagic(entry.path().string(), WHM_MAGIC)) r.whmValid = true;
        }
        if (ext == ".wom") {
            r.hasWom = true;
            if (checkMagic(entry.path().string(), WOM_MAGIC)) r.womValid = true;
        }
        if (ext == ".wob") {
            r.hasWob = true;
            if (checkMagic(entry.path().string(), WOB_MAGIC)) r.wobValid = true;
        }
        if (ext == ".woc") {
            r.hasWoc = true;
            if (checkMagic(entry.path().string(), WOC_MAGIC)) r.wocValid = true;
        }
        if (ext == ".png") r.hasPng = true;
        if (fname == "zone.json") r.hasZoneJson = true;
        if (fname == "creatures.json") r.hasCreatures = true;
        if (fname == "quests.json") r.hasQuests = true;
        if (fname == "objects.json") r.hasObjects = true;
    }
    return r;
}

int ContentPacker::ValidationResult::openFormatScore() const {
    int score = 0;
    if (hasWot) score++;
    if (hasWhm && whmValid) score++;
    if (hasZoneJson) score++;
    if (hasPng) score++;
    if (hasWom && womValid) score++;
    if (hasWob && wobValid) score++;
    if (hasWoc && wocValid) score++;
    return score; // max 7 for fully open
}

std::string ContentPacker::ValidationResult::summary() const {
    std::string s;
    auto add = [&](bool has, bool valid, const char* name) {
        if (!has) return;
        s += name;
        if (!valid) s += "(!)";
        s += " ";
    };
    add(hasWot, true, "WOT");
    add(hasWhm, whmValid, "WHM");
    add(hasWom, womValid, "WOM");
    add(hasWob, wobValid, "WOB");
    add(hasWoc, wocValid, "WOC");
    if (hasZoneJson) s += "zone.json ";
    if (hasPng) s += "PNG ";
    if (hasCreatures) s += "creatures ";
    if (hasQuests) s += "quests ";
    if (hasObjects) s += "objects ";
    return s.empty() ? "(empty)" : s;
}

} // namespace editor
} // namespace wowee