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

module Crafter.Build:Script_impl;
import std;
import :Script;
import :Clang;
import :Platform;
import :Progress;
namespace fs = std::filesystem;
using namespace Crafter;

namespace {
    std::string JoinNames(std::span<const Script> scripts) {
        std::string out;
        for (const Script& script : scripts) {
            if (!out.empty()) out += ", ";
            out += script.name;
        }
        return out;
    }
}

std::int32_t ScriptContext::Run(std::string_view command) const {
    // Echoed by default, unlike a compile step: a script's commands are the
    // only account of what it is doing to the machine.
    if (Progress::GetVerbosity() != Progress::Verbosity::Quiet) std::println("$ {}", command);
    return RunCommandAttached(command);
}

std::int32_t Crafter::RunScript(Configuration& projectCfg, const RunScriptOptions& opts) {
    // Loading the project may have left an in-place status line behind.
    Progress::Clear();

    const std::span<const Script> scripts = projectCfg.scripts;
    if (scripts.empty()) {
        std::println(std::cerr,
R"msg(No scripts defined.
Add them in project.cpp before returning the Configuration:

    cfg.scripts.push_back({{"docs", [](Crafter::ScriptContext& ctx) {{
        return ctx.Run("python3 tools/gen-docs.py");
    }}}});

`crafter-build run docs [args...]` then runs it and exits with what it
returned; ctx.args holds the arguments.)msg");
        return 1;
    }

    // Checked for every script on every run, the list included, so a bad
    // declaration is reported the first time anyone uses `run` and not only
    // when that one name is asked for.
    std::unordered_set<std::string_view> seen;
    for (const Script& script : scripts) {
        if (script.name.empty() || script.name.starts_with('-')) {
            std::println(std::cerr, "script name '{}' cannot be run: a name must not be empty or start with '-'", script.name);
            return 1;
        }
        // Running the first or the last of two would both be a guess, and
        // the usual cause is a pasted line whose name was never changed.
        if (!seen.insert(script.name).second) {
            std::println(std::cerr, "script '{}' is defined twice", script.name);
            return 1;
        }
        if (!script.run) {
            std::println(std::cerr, "script '{}' has no callback", script.name);
            return 1;
        }
    }

    if (opts.listOnly || !opts.named) {
        for (const Script& script : scripts) std::println("{}", script.name);
        return 0;
    }

    const auto found = std::ranges::find(scripts, opts.name, &Script::name);
    if (found == scripts.end()) {
        std::println(std::cerr, "No script named '{}'. Scripts: {}", opts.name, JoinNames(scripts));
        return 1;
    }

    ScriptContext ctx{
        .project = projectCfg,
        // lexically_normal: fs::absolute keeps a "./" component.
        .projectDir = opts.projectFile.empty() ? fs::absolute(projectCfg.path).lexically_normal() : opts.projectFile.parent_path(),
        .args = opts.args,
    };
    try {
        const std::int32_t code = found->run(ctx);
        if (code == 0 || (code >= 1 && code <= 255)) return code;
        std::println(std::cerr, "script '{}' returned {}, which is not an exit status (0..255); exiting with 1", found->name, code);
        return 1;
    } catch (const std::exception& e) {
        // Never let a script's exception unwind across the project.so
        // boundary and out of Run: report it as this script's failure.
        Progress::Clear();
        std::println(std::cerr, "script '{}' failed: {}", found->name, e.what());
        return 1;
    }
}