/*
Crafter® Build
Copyright (C) 2026 Catcrafts®
Catcrafts.net

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License version 3.0 as published by the Free Software Foundation;

This library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
*/

module;
#include "Crafter.Build-Api.h"
export module Crafter.Build:Clang;
import std;
import :Shader;
import :Interface;
import :Implementation;
import :External;
namespace fs = std::filesystem;

export namespace Crafter {
    struct BuildResult {
        std::string result;
        bool repack;
        std::unordered_set<std::string> libs;
        // Compile flags (typically -I include paths) the dep wants its
        // consumers to see — sourced from its external dependencies' include
        // dirs so headers a dep exposes in its public modules are reachable
        // when a consumer #includes them directly. Propagates transitively.
        std::unordered_set<std::string> publicCompileFlags;
    };

    struct Define {
        std::string name;
        std::string value;
    };

    enum class ConfigurationType {
        Executable,
        LibraryStatic,
        LibraryDynamic,
    };

    struct Test;

    struct TestRunner {
        // Quoting style for {args} when this runner is used. Args reach
        // whichever shell the runner ultimately delivers them to: Host for
        // Local + Cmd-prefix (host shell parses), Sh for Ssh (remote bash),
        // Cmd for SshWin (remote cmd.exe).
        enum class Shell { Host, Sh, Cmd };

        std::string copy;
        std::string exec;
        std::string cleanup;
        std::string remoteDir;
        std::string name;
        // Runs once per RunTests invocation (cached by `name`). Exit 0 = runner
        // is available; non-zero = skip every Test using this runner with a
        // "runner unavailable" message. Empty = always available (e.g., Local).
        std::string probe;
        Shell argsShell = Shell::Host;

        bool IsLocal() const { return exec.empty(); }

        static CRAFTER_API TestRunner Local();
        static CRAFTER_API TestRunner Ssh(std::string host, std::string remoteDir = "/tmp/crafter-tests");
        static CRAFTER_API TestRunner SshWin(std::string host, std::string remoteDir = "C:/temp/crafter-tests");
        static CRAFTER_API TestRunner Wsl(std::string remoteDir = "/tmp/crafter-tests-wsl");
        static CRAFTER_API TestRunner Cmd(std::string command);
        static CRAFTER_API std::optional<TestRunner> FromSpec(std::string_view spec);
        static CRAFTER_API TestRunner FromEnv(std::string_view target, TestRunner fallback = Local());
    };

    enum class TestOutcome { Pass, Fail, Crash, Timeout, Skipped };

    struct TestResult {
        std::string name;
        TestOutcome outcome = TestOutcome::Pass;
        int exitCode = 0;
        int signal = 0;
        std::chrono::milliseconds duration{0};
        std::string output;
    };

    // The host target triple, detected once per process by running
    // `clang++ -print-target-triple` and cached. Used as the default for
    // Configuration::target so projects don't have to hardcode it for the
    // no-cross-compile case. Returns "" if clang isn't on PATH or doesn't
    // print a triple — those projects still need an explicit cfg.target.
    CRAFTER_API std::string HostTarget();

    struct Configuration {
        fs::path path;
        std::string outputName;
        std::string name;
        std::string march = "native";
        std::string mtune = "native";
        std::string target = HostTarget();
        std::string sysroot;
        bool debug = false;
        ConfigurationType type = ConfigurationType::Executable;
        std::vector<std::unique_ptr<Module>> interfaces;
        std::vector<Implementation> implementations;
        std::vector<fs::path> cFiles;
        std::vector<fs::path> cuda;
        std::vector<Configuration*> dependencies;
        std::vector<fs::path> files;
        std::vector<Define> defines;
        std::vector<Shader> shaders;
        std::vector<ExternalDependency> externalDependencies;
        std::vector<std::string> compileFlags;
        std::vector<std::string> linkFlags;
        std::vector<Test> tests;
        CRAFTER_API void GetInterfacesAndImplementations(std::span<fs::path> interfaces, std::span<fs::path> implementations);
        // Suffix that uniquely identifies this Configuration's compile state.
        // target+march+mtune are spelled out for readability; the rest
        // (type, debug, sysroot, defines, compileFlags) collapse into a short
        // hash so two Configurations sharing a path but with different
        // compile state can't clobber each other's outputs.
        std::string VariantId() const {
            std::string compileKey;
            compileKey += std::to_string(static_cast<int>(type));
            compileKey += '|';
            compileKey += debug ? '1' : '0';
            compileKey += '|';
            compileKey += sysroot;
            for (const Define& d : defines) {
                compileKey += "|D:";
                compileKey += d.name;
                compileKey += '=';
                compileKey += d.value;
            }
            for (const std::string& f : compileFlags) {
                compileKey += "|F:";
                compileKey += f;
            }
            std::size_t configHash = std::hash<std::string>{}(compileKey);
            return std::format("{}-{}-{}-{}-{:08x}", name, target, march, mtune, configHash);
        }
        fs::path BuildDir() const { return path / "build" / VariantId(); }
        fs::path BinDir() const { return path / "bin" / VariantId(); }
        fs::path PcmDir() const {
            return type == ConfigurationType::Executable ? BuildDir() : BinDir();
        }
    };

    struct Test {
        Configuration config;
        TestRunner runner;
        std::chrono::seconds timeout{60};
        std::vector<std::string> args;
    };

    CRAFTER_API BuildResult Build(Configuration& config, std::unordered_map<fs::path, std::shared_future<BuildResult>>& depResults, std::mutex& depMutex);

    CRAFTER_API int Run(int argc, char** argv);

    // Add a small index.html + runtime.js pair next to the .wasm output so the
    // build can be loaded directly in a browser (just `serve` the bin dir and
    // open it). Opt-in: WASI builds destined for wasmtime/wasmer don't need
    // this and shouldn't carry the extra files. Call from project.cpp after
    // outputName is set; index.html is generated against the current
    // outputName so renaming the binary later requires another call.
    CRAFTER_API void EnableWasiBrowserRuntime(Configuration& cfg);

    // View over the project's args with simple query helpers. Has(flag) for
    // boolean switches; Get(prefix) for valued options (e.g. Get("--prefix=")
    // returns the substring after the equals). Definitions are out-of-line
    // and CRAFTER_API so they cross the Windows DLL boundary cleanly — clang
    // does not emit module-attached in-class inline bodies into consumers.
    struct ArgQuery {
        std::span<const std::string_view> args;
        CRAFTER_API bool Has(std::string_view flag) const;
        CRAFTER_API std::optional<std::string> Get(std::string_view prefix) const;
    };

    // Apply the framework's standard CLI args + env vars onto cfg:
    //   --debug             cfg.debug = true
    //   --target=<triple>   cfg.target = <triple>
    //   --march=<value>     cfg.march = <value>
    //   --mtune=<value>     cfg.mtune = <value>
    //   --lib               cfg.type promoted Executable → LibraryStatic
    //   --shared            cfg.type promoted LibraryStatic → LibraryDynamic
    // Promotions chain in priority order so `--lib --shared` lands on
    // LibraryDynamic regardless of arg order; each is a no-op when the
    // baseline doesn't match (e.g. --shared on an Executable, or --lib on a
    // pre-set library).
    //   $CRAFTER_BUILD_MARCH / $CRAFTER_BUILD_MTUNE seed march/mtune.
    // Env applies first, then args, so CLI wins over env wins over caller's
    // pre-set defaults. Returns an ArgQuery over the same span so projects
    // can query their own flags (`--timing`, ...) without re-rolling the
    // for-arg-in-args loop.
    CRAFTER_API ArgQuery ApplyStandardArgs(Configuration& cfg, std::span<const std::string_view> args);
}