#include "cli_catalog_id_range.hpp"
#include "cli_arg_parse.hpp"
#include "cli_format_table.hpp"

#include <nlohmann/json.hpp>

#include <algorithm>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <filesystem>
#include <fstream>
#include <set>
#include <string>
#include <vector>

namespace wowee {
namespace editor {
namespace cli {

namespace {

namespace fs = std::filesystem;

std::string shellQuote(const std::string& s) {
    std::string out;
    out.reserve(s.size() + 2);
    out.push_back('\'');
    for (char c : s) {
        if (c == '\'') out += "'\"'\"'";
        else out.push_back(c);
    }
    out.push_back('\'');
    return out;
}

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

// Same external-ref filter pattern as cli_catalog_pluck
// + cli_catalog_find. Picks the first non-foreign-key
// *Id field for the displayed range.
bool isExternalRefField(const std::string& k) {
    static const char* kExternals[] = {
        "mapId", "areaId", "spellId", "itemId", "npcId",
        "creatureId", "factionId", "guildId", "soundId",
        "movieId", "displayId", "modelId", "iconId",
        "creatorPlayerId", "emblemId", "animationId",
        "previousRankId", "nextRankId", "difficultyId",
        "instanceId", "raceId", "classId",
        "skillLineId", "questId", "talentId",
        "achievementId", "criteriaId", "lootId",
    };
    for (const char* ref : kExternals) {
        if (k == ref) return true;
    }
    return false;
}

// Extract the primary-key value from one entry. Returns
// {false, 0} if no usable numeric field found.
std::pair<bool, uint64_t>
findEntryPrimaryKey(const nlohmann::json& entry) {
    if (!entry.is_object()) return {false, 0};
    for (auto it = entry.begin(); it != entry.end(); ++it) {
        const std::string& k = it.key();
        if (k.size() >= 2 &&
            k.compare(k.size() - 2, 2, "Id") == 0 &&
            it.value().is_number_integer() &&
            !isExternalRefField(k)) {
            return {true, it.value().get<uint64_t>()};
        }
    }
    for (auto it = entry.begin(); it != entry.end(); ++it) {
        const std::string& k = it.key();
        if (k.size() >= 2 &&
            k.compare(k.size() - 2, 2, "Id") == 0 &&
            it.value().is_number_integer()) {
            return {true, it.value().get<uint64_t>()};
        }
    }
    return {false, 0};
}

std::string runAndCapture(const std::string& cmd, int& outRc) {
    std::string buf;
    FILE* pipe = popen(cmd.c_str(), "r");
    if (!pipe) {
        outRc = 127;
        return buf;
    }
    char chunk[4096];
    while (std::fgets(chunk, sizeof(chunk), pipe) != nullptr) {
        buf += chunk;
    }
    int rc = pclose(pipe);
#ifdef WEXITSTATUS
    outRc = (rc != -1) ? WEXITSTATUS(rc) : rc;
#else
    outRc = rc;
#endif
    return buf;
}

struct FileSummary {
    fs::path path;
    std::string magic;
    size_t entryCount = 0;
    uint64_t minId = 0;
    uint64_t maxId = 0;
    size_t gapCount = 0;        // missing IDs in
                                  // [minId, maxId] range
    uint64_t firstGap = 0;      // smallest unused id in
                                  // the range, 0 if none
    uint64_t recommendedNextId = 1;
};

int handleIdRange(int& i, int argc, char** argv) {
    if (i + 1 >= argc) {
        std::fprintf(stderr,
            "catalog-id-range: usage: --catalog-id-range "
            "<directory> [--magic <WXXX>] [--json]\n");
        return 1;
    }
    std::string dir = argv[++i];
    bool jsonOut = false;
    std::string magicFilter;
    while (i + 1 < argc) {
        if (std::strcmp(argv[i + 1], "--json") == 0) {
            ++i; jsonOut = true;
        } else if (std::strcmp(argv[i + 1], "--magic") == 0 &&
                   i + 2 < argc) {
            ++i;
            magicFilter = argv[++i];
        } else {
            break;
        }
    }
    if (!fs::exists(dir) || !fs::is_directory(dir)) {
        std::fprintf(stderr,
            "catalog-id-range: not a directory: %s\n",
            dir.c_str());
        return 1;
    }

    std::vector<FileSummary> summaries;
    size_t skipped = 0;

    std::error_code walkEc;
    fs::recursive_directory_iterator it(
        dir, fs::directory_options::skip_permission_denied,
        walkEc);
    fs::recursive_directory_iterator end;
    if (walkEc) {
        std::fprintf(stderr,
            "catalog-id-range: cannot open directory: %s\n",
            walkEc.message().c_str());
        return 1;
    }
    for (; it != end; it.increment(walkEc)) {
        if (walkEc) { walkEc.clear(); continue; }
        const auto& dirent = *it;
        if (!dirent.is_regular_file(walkEc)) {
            walkEc.clear(); continue;
        }
        char magic[4]{};
        if (!peekMagic(dirent.path(), magic)) continue;
        const FormatMagicEntry* fmt = findFormatByMagic(magic);
        if (!fmt || !fmt->infoFlag) {
            ++skipped; continue;
        }
        if (!magicFilter.empty()) {
            std::string m(magic, 4);
            if (m != magicFilter) continue;
        }
        std::string base = dirent.path().string();
        if (fmt->extension && *fmt->extension) {
            size_t extLen = std::strlen(fmt->extension);
            if (base.size() >= extLen &&
                base.compare(base.size() - extLen, extLen,
                              fmt->extension) == 0) {
                base.resize(base.size() - extLen);
            }
        }
        std::string cmd = shellQuote(argv[0]) + " " +
                           fmt->infoFlag + " " +
                           shellQuote(base) + " --json 2>/dev/null";
        int rc = 0;
        std::string out = runAndCapture(cmd, rc);
        if (rc != 0 || out.empty()) continue;
        nlohmann::json doc;
        try { doc = nlohmann::json::parse(out); }
        catch (...) { continue; }
        if (!doc.contains("entries") ||
            !doc["entries"].is_array()) continue;

        FileSummary s;
        s.path = dirent.path();
        s.magic = std::string(magic, 4);
        s.entryCount = doc["entries"].size();

        std::set<uint64_t> ids;
        for (const auto& entry : doc["entries"]) {
            auto [ok, key] = findEntryPrimaryKey(entry);
            if (ok) ids.insert(key);
        }
        if (!ids.empty()) {
            s.minId = *ids.begin();
            s.maxId = *ids.rbegin();
            // Count gaps in the [min, max] range.
            for (uint64_t k = s.minId + 1; k < s.maxId; ++k) {
                if (ids.find(k) == ids.end()) {
                    if (s.firstGap == 0) s.firstGap = k;
                    ++s.gapCount;
                }
            }
            // Recommendation: smallest gap in range if any,
            // else max+1.
            s.recommendedNextId = (s.firstGap != 0)
                ? s.firstGap : (s.maxId + 1);
        } else {
            s.recommendedNextId = 1;
        }
        summaries.push_back(s);
    }

    // Sort by path for deterministic output.
    std::sort(summaries.begin(), summaries.end(),
              [](const FileSummary& a, const FileSummary& b) {
                  return a.path < b.path;
              });

    if (jsonOut) {
        nlohmann::json out;
        out["directory"] = dir;
        if (!magicFilter.empty()) out["magicFilter"] = magicFilter;
        out["scanned"] = summaries.size();
        out["skippedNoFlag"] = skipped;
        out["files"] = nlohmann::json::array();
        for (const auto& s : summaries) {
            out["files"].push_back({
                {"path", s.path.string()},
                {"magic", s.magic},
                {"entryCount", s.entryCount},
                {"minId", s.minId},
                {"maxId", s.maxId},
                {"gapCount", s.gapCount},
                {"firstGap", s.firstGap},
                {"recommendedNextId", s.recommendedNextId},
            });
        }
        std::printf("%s\n", out.dump(2).c_str());
        return summaries.empty() ? 1 : 0;
    }

    std::printf("catalog-id-range: %zu catalog files in '%s'",
                summaries.size(), dir.c_str());
    if (!magicFilter.empty()) {
        std::printf(" (magic=%s)", magicFilter.c_str());
    }
    std::printf("\n");
    if (skipped > 0) {
        std::printf("  (skipped %zu files: no --info-* "
                    "surface)\n", skipped);
    }
    if (summaries.empty()) {
        std::printf("  no catalog files found\n");
        return 1;
    }
    std::printf("    magic   count    minId   maxId   gaps  firstGap  recNext  file\n");
    for (const auto& s : summaries) {
        std::printf("    [%s]   %4zu  %7llu  %7llu  %4zu   %7llu  %7llu  %s\n",
                    s.magic.c_str(), s.entryCount,
                    (unsigned long long)s.minId,
                    (unsigned long long)s.maxId,
                    s.gapCount,
                    (unsigned long long)s.firstGap,
                    (unsigned long long)s.recommendedNextId,
                    s.path.string().c_str());
    }
    return 0;
}

} // namespace

bool handleCatalogIdRange(int& i, int argc, char** argv, int& outRc) {
    if (std::strcmp(argv[i], "--catalog-id-range") == 0 &&
        i + 1 < argc) {
        outRc = handleIdRange(i, argc, argv); return true;
    }
    return false;
}

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