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

import std;
import Crafter.Build;
#include "../../lint-rules.h"
namespace fs = std::filesystem;
using namespace Crafter;

// Validates the house-style ruleset in lint-rules.h — the transforms and
// reports this repo (and sibling repos that copy the header) rely on. Each
// case writes a scratch file, runs ONE rule via the glob filter, and asserts
// the findings and/or rewritten bytes.
namespace {
    std::int32_t Failures = 0;

    void Check(bool cond, std::string_view msg) {
        if (!cond) {
            std::println(std::cerr, "FAIL: {}", msg);
            ++Failures;
        }
    }

    struct RuleRun {
        LintSummary summary;
        std::string text; // file content after the run
    };

    RuleRun RunRule(std::string_view content, std::string_view rule, LintMode mode) {
        static std::int32_t Counter = 0;
        fs::path dir = fs::temp_directory_path() / "crafter-build-house-rules" / std::format("case-{}", Counter++);
        fs::remove_all(dir);
        fs::create_directories(dir);
        {
            std::ofstream f(dir / "f.cpp", std::ios::binary | std::ios::trunc);
            f.write(content.data(), static_cast<std::streamsize>(content.size()));
        }
        Configuration cfg;
        cfg.path = dir;
        cfg.name = "house-fixture";
        cfg.outputName = "house-fixture";
        cfg.target = HostTarget();
        std::array<fs::path, 0> ifaces = {};
        std::array<fs::path, 1> impls = { "f" };
        cfg.GetInterfacesAndImplementations(ifaces, impls);
        ProjectLint::AddProjectLintRules(cfg);
        RunLintOptions opts;
        opts.mode = mode;
        opts.globs = { std::string(rule) };
        RuleRun run;
        run.summary = RunLint(cfg, opts);
        std::ifstream f(dir / "f.cpp", std::ios::binary);
        std::stringstream buffer;
        buffer << f.rdbuf();
        run.text = std::move(buffer).str();
        return run;
    }

    bool HasFinding(const LintSummary& s, std::string_view fragment) {
        return std::any_of(s.findings.begin(), s.findings.end(), [&](const LintFinding& f) { return f.message.contains(fragment); });
    }
}

int main() {
    // fixed-width-types: int/long long convert; main/argc and extern "C" stay.
    {
        RuleRun r = RunRule("int Foo(long long v) { int x = 5; return x; }\n" "extern \"C\" int setenv(const char* n, const char* v, int o);\n" "int main(int argc, char** argv) { return 0; }\n", "fixed-width-types", LintMode::Apply);
        Check(r.text.contains("std::int32_t Foo(std::int64_t v) { std::int32_t x = 5;"), "fixed-width converts int and long long");
        Check(r.text.contains("extern \"C\" int setenv"), "extern \"C\" prototype keeps int");
        Check(r.text.contains("int main(int argc"), "main/argc keep int");
    }

    // fixed-width-types is signed/unsigned aware, in any specifier order;
    // bare char (text) and long double (floating) are not integers.
    {
        RuleRun r = RunRule("void F() {\n"
                            "    unsigned a = 1;\n"
                            "    unsigned int b = 2;\n"
                            "    unsigned long long c = 3;\n"
                            "    long unsigned int d = 4;\n"
                            "    unsigned short e = 5;\n"
                            "    signed f = 6;\n"
                            "    signed char g = 7;\n"
                            "    auto h = static_cast<unsigned char>(g);\n"
                            "    char text = 'x';\n"
                            "    long double pi = 3.14L;\n"
                            "}\n",
                            "fixed-width-types", LintMode::Apply);
        Check(r.text.contains("std::uint32_t a = 1;"), "bare unsigned -> uint32");
        Check(r.text.contains("std::uint32_t b = 2;"), "unsigned int -> uint32");
        Check(r.text.contains("std::uint64_t c = 3;"), "unsigned long long -> uint64");
        Check(r.text.contains("std::uint64_t d = 4;"), "long unsigned int (reordered) -> uint64");
        Check(r.text.contains("std::uint16_t e = 5;"), "unsigned short -> uint16");
        Check(r.text.contains("std::int32_t f = 6;"), "bare signed -> int32");
        Check(r.text.contains("std::int8_t g = 7;"), "signed char -> int8");
        Check(r.text.contains("static_cast<std::uint8_t>(g)"), "unsigned char -> uint8");
        Check(r.text.contains("char text = 'x';"), "bare char stays (text, not an integer)");
        Check(r.text.contains("long double pi = 3.14L;"), "long double stays (floating type)");
    }

    // brace-style: Allman brace joins; standalone scope block stays.
    {
        RuleRun r = RunRule("void Foo()\n{\n}\n\nvoid Bar() {\n    Baz();\n    {\n        Qux();\n    }\n}\n", "brace-style", LintMode::Apply);
        Check(r.text.contains("void Foo() {"), "Allman brace joined onto header");
        Check(r.text.contains("Baz();\n    {"), "scope block brace untouched");
    }

    // if-single-line: short body joins; braced body stays.
    {
        RuleRun r = RunRule("void F(bool b) {\n    if (b)\n        Run();\n    if (b) {\n        Run();\n    }\n}\n", "if-single-line", LintMode::Apply);
        Check(r.text.contains("if (b) Run();"), "single-statement if body joined");
        Check(r.text.contains("if (b) {"), "braced if body untouched");
    }

    // single-declaration: simple multi-decl splits; pointer decl only reports.
    {
        RuleRun r = RunRule("void F() {\n    bool a = false, b = true;\n}\n", "single-declaration", LintMode::Apply);
        Check(r.text.contains("bool a = false;\n    bool b = true;"), "multi-declaration split");
    }

    // wrap-join: short wrapped call joins; operator chain joins; long stays.
    {
        RuleRun r = RunRule("void F() {\n    G(alpha,\n      beta);\n    bool x = alpha\n        && beta;\n}\n", "wrap-join", LintMode::Apply);
        Check(r.text.contains("G(alpha, beta);"), "wrapped call arguments joined");
        Check(r.text.contains("bool x = alpha && beta;"), "operator continuation joined");
    }

    // format-concat: literal-adjacent + rewrites; += RHS rewrites; args survive.
    {
        RuleRun r = RunRule("void F(std::string name, std::string cmd) {\n"
                            "    std::string a = name + \".cpp\";\n"
                            "    std::string b = \"pre-\" + name + \"-post\";\n"
                            "    cmd += \" \" + name;\n"
                            "    std::string keep = name + cmd;\n"
                            "    fs::path p;\n"
                            "    std::string c = p.stem().string() + \".pcm\";\n"
                            "    fs::path d = std::string(cmd) + \".so\";\n"
                            "}\n",
                            "format-concat", LintMode::Apply);
        Check(r.text.contains("std::string a = std::format(\"{}.cpp\", name);"), "trailing literal converts");
        Check(!r.text.contains("namestd::format"), "replacement splices at the operand boundary");
        Check(r.text.contains("std::string b = std::format(\"pre-{}-post\", name);"), "sandwich chain converts");
        Check(r.text.contains("cmd += std::format(\" {}\", name);"), "+= RHS converts");
        Check(r.text.contains("std::string keep = name + cmd;"), "literal-free + is left alone");
        Check(r.text.contains("std::string c = std::format(\"{}.pcm\", p.stem().string());"), "call-chain left operand consumed whole (the stringstd regression)");
        Check(r.text.contains("fs::path d = std::format(\"{}.so\", std::string(cmd));"), "constructor-call left operand consumed whole");
    }
    {
        // Ternary and raw-string lines are reported, never rewritten.
        RuleRun r = RunRule("std::string F(bool b, std::string n) { return b ? n + \".x\" : n; }\n", "format-concat", LintMode::Report);
        Check(HasFinding(r.summary, "not auto-fixable"), "ternary concat reports instead of fixing");
        Check(r.text.contains("n + \".x\""), "ternary concat untouched on disk");
    }

    // paren-spacing: single-space padding removed; wrapped call ends keep.
    {
        RuleRun r = RunRule("void F() {\n    G( x );\n}\n", "paren-spacing", LintMode::Apply);
        Check(r.text.contains("G(x);"), "paren padding removed");
    }

    // naming: wrong-case function/type/static/global flagged; camel local passes.
    {
        RuleRun r = RunRule("namespace {\n"
                            "    std::int32_t bad_global = 0;\n"
                            "    struct lint_thing {};\n"
                            "}\n"
                            "void lower_func() {\n"
                            "    static bool lowerStatic = false;\n"
                            "    std::int32_t fineLocal = 1;\n"
                            "}\n",
                            "naming", LintMode::Report);
        Check(HasFinding(r.summary, "'bad_global' should be PascalCase"), "lowercase global flagged");
        Check(HasFinding(r.summary, "'lint_thing' should be PascalCase"), "lowercase type flagged");
        Check(HasFinding(r.summary, "'lower_func' should be PascalCase"), "lowercase function flagged");
        Check(HasFinding(r.summary, "'lowerStatic' should be PascalCase"), "camel static flagged");
        Check(!HasFinding(r.summary, "fineLocal"), "camelCase local passes");
    }
    {
        // Statement calls with inline lambda arguments are NOT function
        // definitions (the any_of regression); a genuine lowercase one-liner
        // method still is.
        RuleRun r = RunRule("struct Holder {\n"
                            "    bool clean() const { return true; }\n"
                            "};\n"
                            "void T(std::vector<std::int32_t>& v) {\n"
                            "    bool x = std::any_of(v.begin(), v.end(), [](std::int32_t n) { return n > 0; });\n"
                            "    std::erase_if(v, [](std::int32_t n) { return n < 0; });\n"
                            "}\n",
                            "naming", LintMode::Report);
        Check(!HasFinding(r.summary, "any_of"), "call with lambda argument is not a function definition");
        Check(!HasFinding(r.summary, "erase_if"), "bare statement call is not a function definition");
        Check(HasFinding(r.summary, "'clean' should be PascalCase"), "lowercase one-liner method still flagged");
    }

    // enum-class + no-iostream-print reports.
    {
        RuleRun r = RunRule("enum Color { Red };\n", "enum-class", LintMode::Report);
        Check(HasFinding(r.summary, "enum class"), "plain enum flagged");
    }
    {
        RuleRun r = RunRule("void F() { std::cout << 1; }\n", "no-iostream-print", LintMode::Report);
        Check(HasFinding(r.summary, "std::println"), "std::cout flagged");
    }

    // The whole ruleset is idempotent: a second Apply changes nothing.
    {
        std::string_view source = "int Foo()\n{\n    std::string s = std::string(\"a\") + \"b\";\n    if (true)\n        return 1;\n    return 0;\n}\n";
        static constexpr std::string_view AllRules = "*";
        RuleRun first = RunRule(source, AllRules, LintMode::Apply);
        RuleRun second = RunRule(first.text, AllRules, LintMode::Apply);
        Check(second.summary.changedFiles.empty(), "second apply of the full ruleset is a no-op");
        Check(first.text != source, "first apply actually changed the fixture");
    }

    // Suppression directives against house transforms: the driver reverts
    // line-preserving edits (fixed-width) and the count-changing rules check
    // Suppressed() themselves (wrap-join).
    {
        RuleRun r = RunRule("void F() {\n"
                            "    // lint-disable-next-line fixed-width-types\n"
                            "    int keep = 1;\n"
                            "    int convert = 2;\n"
                            "}\n",
                            "fixed-width-types", LintMode::Apply);
        Check(r.text.contains("int keep = 1;"), "next-line directive keeps the suppressed int");
        Check(r.text.contains("std::int32_t convert = 2;"), "unsuppressed line still converts");
    }
    {
        RuleRun r = RunRule("void F() {\n"
                            "    // lint-disable-next-line wrap-join\n"
                            "    G(alpha,\n"
                            "      beta);\n"
                            "    H(alpha,\n"
                            "      beta);\n"
                            "}\n",
                            "wrap-join", LintMode::Apply);
        Check(r.text.contains("G(alpha,\n"), "suppressed wrap stays wrapped");
        Check(r.text.contains("H(alpha, beta);"), "unsuppressed wrap still joins");
    }

    // wrap-join converges in ONE run: joining the inner paren wrap balances
    // the && line, which only then becomes an operator-joinable continuation.
    {
        RuleRun r = RunRule("void F() {\n"
                            "    bool ok = alpha\n"
                            "        && beta(gamma,\n"
                            "                delta);\n"
                            "}\n",
                            "wrap-join", LintMode::Apply);
        Check(r.text.contains("bool ok = alpha && beta(gamma, delta);"), "self-enabling joins reach the fixpoint in one apply");
        RuleRun second = RunRule(r.text, "wrap-join", LintMode::Apply);
        Check(second.summary.changedFiles.empty(), "wrap-join is idempotent after the fixpoint");
    }

    if (Failures > 0) {
        std::println(std::cerr, "{} assertions failed", Failures);
        return 1;
    }
    return 0;
}