/**
 * @file test_metadata.cpp
 * @brief Module records: installation, removal, and listing without loading
 *
 * @copyright Copyright (c) 2026 SILO GROUP LLC
 * @author Chris Punches <chris.punches@silogroup.org>
 *
 * Part of the Dark Horse Linux Package Manager (DPM)
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 */
#include "harness.hpp"

#include <filesystem>
#include <string>

namespace fs = std::filesystem;

int main(void) {
    const std::string scratch = std::string(TEST_SCRATCH_ROOT) + "/metadata";

    /* ---- listing reads records and marks what has none ---- */
    {
        dpm_open_overrides overrides = {TEST_FIXTURE_CONF,
                                        TEST_FIXTURE_MODULES, nullptr, -1,
                                        TEST_FIXTURE_METADATA};
        dpm_ctx* ctx = dpm_open(&overrides);
        CHECK(ctx != nullptr);
        if (!ctx) {
            std::fprintf(stderr, "cannot continue without a context\n");
            return 1;
        }

        dpm_cursor* cur = dpm_list_modules(ctx);
        CHECK(cur != nullptr);
        if (cur) {
            int count = 0;
            int uninstalled = 0;
            bool saw_good = false;

            dpm_module_info info;
            while (dpm_cursor_next(cur, &info) == 0) {
                count++;
                CHECK(info.name != nullptr);
                CHECK(info.version != nullptr);
                CHECK(info.description != nullptr);

                if (std::strcmp(info.name, "good") == 0) {
                    saw_good = true;
                    CHECK(std::strcmp(info.version, "1.2.3") == 0);
                    CHECK(*info.description);
                }
                if (std::strcmp(info.version, "<uninstalled>") == 0) {
                    uninstalled++;
                }
            }

            /* every .so present is reported, recorded or not */
            CHECK(count == 3);
            CHECK(saw_good);
            CHECK(uninstalled == 2);
            dpm_cursor_free(cur);
        }

        /* the cursor reports nothing further once exhausted */
        cur = dpm_list_modules(ctx);
        CHECK(cur != nullptr);
        if (cur) {
            dpm_module_info info;
            while (dpm_cursor_next(cur, &info) == 0) {
            }
            CHECK(dpm_cursor_next(cur, &info) != 0);
            dpm_cursor_free(cur);
        }

        CHECK(dpm_cursor_next(nullptr, nullptr) != 0);
        dpm_cursor_free(nullptr);

        /* an unreadable module path refuses with a reason */
        dpm_open_overrides bad_path = {TEST_FIXTURE_CONF, "/does/not/exist",
                                       nullptr, -1, TEST_FIXTURE_METADATA};
        dpm_ctx* bad = dpm_open(&bad_path);
        CHECK(bad != nullptr);
        if (bad) {
            CHECK(dpm_list_modules(bad) == nullptr);
            CHECK(error_contains(bad, "module path"));
            dpm_close(bad);
        }

        CHECK(dpm_list_modules(nullptr) == nullptr);
        dpm_close(ctx);
    }

    /* ---- installation writes a record a later context reads back ---- */
    {
        fs::remove_all(scratch);

        dpm_open_overrides overrides = {TEST_FIXTURE_CONF,
                                        TEST_FIXTURE_MODULES, nullptr, -1,
                                        scratch.c_str()};
        dpm_ctx* ctx = dpm_open(&overrides);
        CHECK(ctx != nullptr);
        if (!ctx) {
            std::fprintf(stderr, "cannot continue without a context\n");
            return 1;
        }

        /* a module that cannot load cannot be installed */
        CHECK(dpm_install_module(ctx, "bad_version") != 0);
        CHECK(error_contains(ctx, "malformed version"));
        CHECK(dpm_install_module(ctx, "nonexistent") != 0);
        CHECK(dpm_install_module(ctx, nullptr) != 0);
        CHECK(dpm_install_module(nullptr, "good") != 0);

        CHECK(dpm_install_module(ctx, "good") == 0);
        CHECK(fs::exists(scratch + "/good.meta"));

        /* the record answers a fresh context without opening the module */
        dpm_ctx* reader = dpm_open(&overrides);
        CHECK(reader != nullptr);
        if (reader) {
            dpm_cursor* cur = dpm_list_modules(reader);
            CHECK(cur != nullptr);
            if (cur) {
                bool found = false;
                dpm_module_info info;
                while (dpm_cursor_next(cur, &info) == 0) {
                    if (std::strcmp(info.name, "good") == 0) {
                        found = true;
                        CHECK(std::strcmp(info.version, "1.2.3") == 0);
                        CHECK(std::strcmp(info.description,
                                          "Known-good stub module.") == 0);
                    }
                }
                CHECK(found);
                dpm_cursor_free(cur);
            }
            dpm_close(reader);
        }

        /* installing again over an existing record succeeds */
        CHECK(dpm_install_module(ctx, "good") == 0);

        /* removal takes the record and leaves the module file alone */
        CHECK(dpm_uninstall_module(ctx, "good") == 0);
        CHECK(!fs::exists(scratch + "/good.meta"));
        CHECK(dpm_uninstall_module(ctx, "good") != 0);
        CHECK(dpm_uninstall_module(ctx, nullptr) != 0);
        CHECK(dpm_uninstall_module(nullptr, "good") != 0);

        /* the module still loads by its own name once uninstalled */
        dpm_ctx* after = dpm_open(&overrides);
        CHECK(after != nullptr);
        if (after) {
            CHECK(dpm_require(after, "good") != nullptr);
            dpm_close(after);
        }

        dpm_close(ctx);
    }

    /* ---- an unwritable metadata directory fails without throwing ---- */
    {
        dpm_open_overrides readonly = {TEST_FIXTURE_CONF, TEST_FIXTURE_MODULES,
                                       nullptr, -1, "/proc/dpm-metadata"};
        dpm_ctx* ctx = dpm_open(&readonly);
        CHECK(ctx != nullptr);
        if (ctx) {
            CHECK(dpm_install_module(ctx, "good") != 0);

            /* listing and loading carry on with no records available */
            dpm_cursor* cur = dpm_list_modules(ctx);
            CHECK(cur != nullptr);
            if (cur) {
                dpm_cursor_free(cur);
            }
            CHECK(dpm_require(ctx, "good") != nullptr);
            dpm_close(ctx);
        }
    }

    return harness_report("metadata");
}