// SPDX-License-Identifier: LGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (C) 2026 Catcrafts®

export module Crafter.Build:Platform;
import std;
namespace fs = std::filesystem;

namespace Crafter {
    struct Configuration;
    struct CommandResult {
        std::int32_t exitCode = 0;
        std::string output;
        bool crashed = false;
        bool timedOut = false;
        std::int32_t signal = 0;
    };
    // An exclusive lock on the file `path` (created if missing), held from
    // construction to destruction. An flock, so it keeps out the other
    // threads of this process (each opens the file anew) and other
    // crafter-build processes alike. The OS drops it when the descriptor
    // closes, process death included, so an interrupted build never leaves a
    // stale lock; the descriptor is close-on-exec, so the tools a holder
    // spawns don't keep it past its release.
    class FileLock {
        std::int32_t fd = -1;
    public:
        explicit FileLock(const fs::path& path);
        ~FileLock();
        FileLock(const FileLock&) = delete;
        FileLock& operator=(const FileLock&) = delete;
    };
    std::string BuildStdPcm(const Configuration& config, fs::path stdPcm);
    fs::path GetCacheDir();
    CommandResult RunCommandChecked(std::string_view command);
    // A compile / link / archive step. Success is the command's exit status,
    // never whether it printed anything: a warning does not stop the compiler
    // from writing a valid object, and warnings are only emitted when a
    // translation unit is actually recompiled — so keying failure off the
    // output made the same unchanged source pass or fail depending on whether
    // its object happened to be up to date.
    //
    // Returns an empty string on success (any warnings go to the user via
    // Progress::Diagnostic), otherwise the compiler's diagnostics. Callers
    // therefore keep the `if (!result.empty())` shape they already had.
    std::string RunBuildCommand(std::string_view command);
    export CommandResult RunCommandWithTimeout(std::string_view command, std::chrono::seconds timeout);
    // Runs `command` through sh with this process's own stdin, stdout and
    // stderr, so its output appears as it is produced and it can prompt.
    // Every helper above captures instead, which suits a compile step and
    // not a command that runs for half an hour. Returns the exit code, or
    // 128+signal when the command was killed; a nonzero exit is the caller's
    // to judge and never throws. While it runs, Ctrl-C goes to the command
    // and not to crafter-build, which then sees it as exit code 130.
    // Project scripts reach this through ScriptContext::Run.
    std::int32_t RunCommandAttached(std::string_view command);
    // `s` as one single-quoted sh word, safe to splice into a command line
    // whatever it contains: paths with spaces, arguments a user typed.
    export std::string ShellQuote(std::string_view s);
    std::string GetBaseCommand(const Configuration& config);
    export Configuration LoadProject(const fs::path& projectFile, std::span<const std::string_view> args);
    // A dependency the project file currently running its CrafterBuildProject
    // declared with `#pragma crafter dependency`, so it can also be wired
    // into the build graph (a test that links the same module, say) without
    // spelling the source twice. `name` is the dependency's Configuration
    // name or any module it exports — whatever the project file `import`s.
    // Throws when no such dependency was declared, or when called from
    // anywhere other than inside LoadProject.
    export Configuration* ProjectDependency(std::string_view name);
    // True while the project file crafter-build was pointed at runs its
    // CrafterBuildProject, and when no project file is running at all; false
    // inside a dependency's project file (a `#pragma crafter dependency`,
    // GitProject or LocalProject target). Wire anything only the project's
    // own build or test run needs behind it. The case that forced it: a
    // library's test links crafter-build itself, so when crafter-build loads
    // that library as a dependency, the test's GitProject loads crafter-build's
    // project file in turn and the two recurse until the cycle guard throws.
    export bool IsTopLevelProject();
    // Resolves the directory holding distributed runtime assets (Crafter.Build
    // module sources, wasi-runtime/, etc). Honors CRAFTER_BUILD_HOME; otherwise
    // derives <prefix>/share/crafter-build from the running executable's path.
    export fs::path GetCrafterBuildHome();
    // Newest mtime among the prerequisites a compiler recorded in `depFile`
    // (clang's `-MD -MF <artifact>.d`). This is how a build step learns which
    // headers its source pulled in: the module scanner only reads `import`
    // lines, so an `#include`d file is invisible to it until the compiler
    // reports what it actually opened.
    //
    // Returns file_time_type::max() when freshness cannot be proven — no
    // depfile (nothing has compiled this artifact since depfiles were emitted,
    // including every object left over from an older crafter-build) or a
    // prerequisite that no longer exists. Callers compare the result against
    // their artifact's mtime, so max() reads as "rebuild".
    fs::file_time_type NewestPrerequisite(const fs::path& depFile);
    // Wildcard name matching ('*', '?') shared by the test and lint verbs.
    bool MatchGlob(std::string_view glob, std::string_view name);
    // Empty `globs` matches everything.
    bool MatchAny(std::span<const std::string> globs, std::string_view name);
}