#include "pch.h"

#include "vcpkg_Commands.h"
#include "vcpkg_Dependencies.h"
#include "vcpkg_Input.h"
#include "vcpkg_System.h"
#include "vcpkg_Util.h"
#include "vcpkglib.h"

namespace vcpkg::Commands::Remove
{
    using Dependencies::RemovePlanAction;
    using Dependencies::RemovePlanType;
    using Dependencies::RequestType;
    using Update::OutdatedPackage;

    static void remove_package(const VcpkgPaths& paths, const PackageSpec& spec, StatusParagraphs* status_db)
    {
        auto& fs = paths.get_filesystem();
        StatusParagraph& pkg = **status_db->find(spec.name(), spec.triplet());

        pkg.want = Want::PURGE;
        pkg.state = InstallState::HALF_INSTALLED;
        write_update(paths, pkg);

        auto maybe_lines = fs.read_lines(paths.listfile_path(pkg.package));

        if (auto lines = maybe_lines.get())
        {
            std::vector<fs::path> dirs_touched;
            for (auto&& suffix : *lines)
            {
                if (!suffix.empty() && suffix.back() == '\r') suffix.pop_back();

                std::error_code ec;

                auto target = paths.installed / suffix;

                auto status = fs.status(target, ec);
                if (ec)
                {
                    System::println(System::Color::error, "failed: %s", ec.message());
                    continue;
                }

                if (fs::is_directory(status))
                {
                    dirs_touched.push_back(target);
                }
                else if (fs::is_regular_file(status))
                {
                    fs.remove(target, ec);
                    if (ec)
                    {
                        System::println(System::Color::error, "failed: %s: %s", target.u8string(), ec.message());
                    }
                }
                else if (!fs::status_known(status))
                {
                    System::println(System::Color::warning, "Warning: unknown status: %s", target.u8string());
                }
                else
                {
                    System::println(System::Color::warning, "Warning: %s: cannot handle file type", target.u8string());
                }
            }

            auto b = dirs_touched.rbegin();
            auto e = dirs_touched.rend();
            for (; b != e; ++b)
            {
                if (fs.is_empty(*b))
                {
                    std::error_code ec;
                    fs.remove(*b, ec);
                    if (ec)
                    {
                        System::println(System::Color::error, "failed: %s", ec.message());
                    }
                }
            }

            fs.remove(paths.listfile_path(pkg.package));
        }

        pkg.state = InstallState::NOT_INSTALLED;
        write_update(paths, pkg);
    }

    static void print_plan(const std::map<RemovePlanType, std::vector<const RemovePlanAction*>>& group_by_plan_type)
    {
        static constexpr std::array<RemovePlanType, 2> order = {RemovePlanType::NOT_INSTALLED, RemovePlanType::REMOVE};

        for (const RemovePlanType plan_type : order)
        {
            auto it = group_by_plan_type.find(plan_type);
            if (it == group_by_plan_type.cend())
            {
                continue;
            }

            std::vector<const RemovePlanAction*> cont = it->second;
            std::sort(cont.begin(), cont.end(), &RemovePlanAction::compare_by_name);
            const std::string as_string = Strings::join("\n", cont, [](const RemovePlanAction* p) {
                return Dependencies::to_output_string(p->request_type, p->spec.to_string());
            });

            switch (plan_type)
            {
                case RemovePlanType::NOT_INSTALLED:
                    System::println("The following packages are not installed, so not removed:\n%s", as_string);
                    continue;
                case RemovePlanType::REMOVE:
                    System::println("The following packages will be removed:\n%s", as_string);
                    continue;
                default: Checks::unreachable(VCPKG_LINE_INFO);
            }
        }
    }

    void perform_and_exit(const VcpkgCmdArguments& args, const VcpkgPaths& paths, const Triplet& default_triplet)
    {
        static const std::string OPTION_PURGE = "--purge";
        static const std::string OPTION_NO_PURGE = "--no-purge";
        static const std::string OPTION_RECURSE = "--recurse";
        static const std::string OPTION_DRY_RUN = "--dry-run";
        static const std::string OPTION_OUTDATED = "--outdated";
        static const std::string example =
            Commands::Help::create_example_string("remove zlib zlib:x64-windows curl boost");
        const std::unordered_set<std::string> options = args.check_and_get_optional_command_arguments(
            {OPTION_PURGE, OPTION_NO_PURGE, OPTION_RECURSE, OPTION_DRY_RUN, OPTION_OUTDATED});

        StatusParagraphs status_db = database_load_check(paths);
        std::vector<PackageSpec> specs;
        if (options.find(OPTION_OUTDATED) != options.cend())
        {
            args.check_exact_arg_count(0, example);
            specs = Util::fmap(Update::find_outdated_packages(paths, status_db),
                               [](auto&& outdated) { return outdated.spec; });

            if (specs.empty())
            {
                System::println(System::Color::success, "There are no oudated packages.");
                Checks::exit_success(VCPKG_LINE_INFO);
            }
        }
        else
        {
            args.check_min_arg_count(1, example);
            specs = Util::fmap(args.command_arguments, [&](auto&& arg) {
                return Input::check_and_get_package_spec(arg, default_triplet, example);
            });

            for (auto&& spec : specs)
                Input::check_triplet(spec.triplet(), paths);
        }

        const bool alsoRemoveFolderFromPackages = options.find(OPTION_NO_PURGE) == options.end();
        if (options.find(OPTION_PURGE) != options.end() && !alsoRemoveFolderFromPackages)
        {
            // User specified --purge and --no-purge
            System::println(System::Color::error, "Error: cannot specify both --no-purge and --purge.");
            System::print(example);
            Checks::exit_fail(VCPKG_LINE_INFO);
        }
        const bool isRecursive = options.find(OPTION_RECURSE) != options.cend();
        const bool dryRun = options.find(OPTION_DRY_RUN) != options.cend();

        const std::vector<RemovePlanAction> remove_plan = Dependencies::create_remove_plan(specs, status_db);
        Checks::check_exit(VCPKG_LINE_INFO, !remove_plan.empty(), "Remove plan cannot be empty");

        std::map<RemovePlanType, std::vector<const RemovePlanAction*>> group_by_plan_type;
        Util::group_by(remove_plan, &group_by_plan_type, [](const RemovePlanAction& p) { return p.plan_type; });
        print_plan(group_by_plan_type);

        const bool has_non_user_requested_packages =
            Util::find_if(remove_plan, [](const RemovePlanAction& package) -> bool {
                return package.request_type != RequestType::USER_REQUESTED;
            }) != remove_plan.cend();

        if (has_non_user_requested_packages)
        {
            System::println(System::Color::warning,
                            "Additional packages (*) need to be removed to complete this operation.");

            if (!isRecursive)
            {
                System::println(System::Color::warning,
                                "If you are sure you want to remove them, run the command with the --recurse option");
                Checks::exit_fail(VCPKG_LINE_INFO);
            }
        }

        if (dryRun)
        {
            Checks::exit_success(VCPKG_LINE_INFO);
        }

        for (const RemovePlanAction& action : remove_plan)
        {
            const std::string display_name = action.spec.to_string();

            switch (action.plan_type)
            {
                case RemovePlanType::NOT_INSTALLED:
                    System::println(System::Color::success, "Package %s is not installed", display_name);
                    break;
                case RemovePlanType::REMOVE:
                    System::println("Removing package %s... ", display_name);
                    remove_package(paths, action.spec, &status_db);
                    System::println(System::Color::success, "Removing package %s... done", display_name);
                    break;
                case RemovePlanType::UNKNOWN:
                default: Checks::unreachable(VCPKG_LINE_INFO);
            }

            if (alsoRemoveFolderFromPackages)
            {
                System::println("Purging package %s... ", display_name);
                Files::Filesystem& fs = paths.get_filesystem();
                std::error_code ec;
                fs.remove_all(paths.packages / action.spec.dir(), ec);
                System::println(System::Color::success, "Purging package %s... done", display_name);
            }
        }

        Checks::exit_success(VCPKG_LINE_INFO);
    }
}