/**
 * @file linker_test.cpp
 * @brief 链接测试：用例 09/10/11/12/16/19 + line1 正例
 * @author 
 * @date 2026-08-21
 */

#include <cstdio>
#include <string>
#include <vector>

#include "compiler/Linker.h"
#include "compiler/Project.h"

#ifndef REPO_ROOT
#define REPO_ROOT "."
#endif

static int g_checks = 0;

#define CHECK(cond)                                                     \
    do {                                                                \
        if (!(cond)) {                                                  \
            std::printf("FAIL %s:%d: %s\n", __FILE__, __LINE__, #cond); \
            return false;                                               \
        }                                                               \
        ++g_checks;                                                     \
    } while (0)

// 从用例目录加载工程并链接
static bool link_case(const char* dir, compiler::LinkResult* out, std::string* err) {
    using namespace compiler;
    const std::string toml = std::string(REPO_ROOT) + "/tests/cases/" + dir + "/project.toml";
    Project p;
    if (!parse_project(toml, &p, err)) {
        return false;
    }
    std::vector<SourceUnit> units;
    for (const std::string& f : compile_files(p)) {
        SourceUnit u;
        if (!load_unit(p.base_dir + "/" + f, &u, err)) {
            return false;
        }
        units.push_back(std::move(u));
    }
    return link_project(p, units, out, err);
}

static bool expect_link_err(const char* dir, const char* keyword) {
    compiler::LinkResult r;
    std::string err;
    if (link_case(dir, &r, &err)) {
        std::printf("FAIL %s: linked ok\n", dir);
        return false;
    }
    if (err.find("link error") != 0) {
        std::printf("FAIL %s: want 'link error', got '%s'\n", dir, err.c_str());
        return false;
    }
    if (err.find(keyword) == std::string::npos) {
        std::printf("FAIL %s: want '%s', got '%s'\n", dir, keyword, err.c_str());
        return false;
    }
    ++g_checks;
    return true;
}

// ---- 1. 用例 09：GVL + VAR_EXTERNAL 同一槽 ----

static bool test_case09() {
    using namespace compiler;
    LinkResult r;
    std::string err;
    CHECK(link_case("09_gvl_external", &r, &err));
    CHECK(r.globals.size() == 1);
    CHECK(r.globals[0].name == "g1");
    CHECK(r.globals[0].kind == SymbolKind::Global);
    CHECK(r.globals[0].type_name == "int");
    CHECK(r.globals[0].address == 0);

    CHECK(r.scopes.size() == 1);
    const LinkResult::PouScope& main = r.scopes[0];
    CHECK(main.name == "main");
    bool saw_external = false;
    for (const Symbol& s : main.syms) {
        if (s.name == "g1") {
            saw_external = true;
            CHECK(s.kind == SymbolKind::External);
            CHECK(s.address == 0);  // 同一槽
            CHECK(s.type_name == "int");
        }
    }
    // 符号表打印：name kind type address file
    const std::string dump = dump_symbols(r);
    CHECK(dump.find("g1 global int 0 ") != std::string::npos);
    CHECK(dump.find("[main]") != std::string::npos);
    CHECK(dump.find("g1 external int 0 ") != std::string::npos);
    return true;
}

// ---- 2. 用例 10 / 11 / 12 ----

static bool test_neg_cases() {
    if (!expect_link_err("10_gvl_wrong_file", "VAR_GLOBAL only allowed in gvl file")) {
        return false;
    }
    if (!expect_link_err("11_duplicate_global", "duplicate global")) {
        return false;
    }
    if (!expect_link_err("12_io_unknown_var", "io.var 'Nope' not in GVL")) {
        return false;
    }
    return true;
}

// ---- 3. 用例 16：未声明实例 ----

static bool test_case16() {
    if (!expect_link_err("16_fb_undeclared", "undeclared FB instance")) {
        return false;
    }
    return true;
}

// ---- 4. 用例 19：循环调用 ----

static bool test_case19() {
    if (!expect_link_err("19_recursive_call", "recursive call")) {
        return false;
    }
    return true;
}

// ---- 5. line1 正例：全局槽序 / FB 布局 / 字段 / 实例 ----

static bool test_line1() {
    using namespace compiler;
    LinkResult r;
    std::string err;
    const std::string toml = std::string(REPO_ROOT) + "/examples/line1/project.toml";
    Project p;
    CHECK(parse_project(toml, &p, &err));
    std::vector<SourceUnit> units;
    for (const std::string& f : compile_files(p)) {
        SourceUnit u;
        CHECK(load_unit(p.base_dir + "/" + f, &u, &err));
        units.push_back(std::move(u));
    }
    CHECK(link_project(p, units, &r, &err));

    // 全局槽序 = 声明顺序
    CHECK(r.globals.size() == 4);
    CHECK(r.globals[0].name == "emergencystop");
    CHECK(r.globals[1].name == "i0_0");
    CHECK(r.globals[2].name == "i0_1");
    CHECK(r.globals[3].name == "q0_0");

    // 用户 FB 布局：MotorStarter 字段 = input/output（external 不是字段）
    const auto it = r.fb_types.find("motorstarter");
    CHECK(it != r.fb_types.end());
    CHECK(it->second.fields.size() == 3);
    CHECK(it->second.fields[0].name == "start");
    CHECK(it->second.fields[1].name == "stop");
    CHECK(it->second.fields[2].name == "q");
    CHECK(it->second.fields[2].type == TypeKind::Bool);

    // 内建 TON 布局（用例 17 的 t）
    const FbLayout* ton = nullptr;
    for (const auto& [name, lay] : r.fb_types) {
        (void)name;
        (void)lay;
    }
    // 直接构造 TON 实例验证内建表（见 case17 用）
    // main 作用域：starter 实例 + 字段引用
    CHECK(r.scopes.size() == 2);  // motorstarter + main
    const LinkResult::PouScope& main = r.scopes[1];
    bool saw_starter = false;
    for (const Symbol& s : main.syms) {
        if (s.name == "starter") {
            saw_starter = true;
            CHECK(s.kind == SymbolKind::FbInstance);
            CHECK(s.type_name == "motorstarter");
        }
    }
    CHECK(saw_starter);
    const auto sit = main.fb_instances.find("starter");
    CHECK(sit != main.fb_instances.end());
    CHECK(sit->second.fields.size() == 3);
    return true;
}

// ---- 6. 内建 FB 布局（TON）----

static bool test_builtin() {
    using namespace compiler;
    LinkResult r;
    std::string err;
    const std::string toml = std::string(REPO_ROOT) + "/tests/cases/17_ton/project.toml";
    Project p;
    CHECK(parse_project(toml, &p, &err));
    std::vector<SourceUnit> units;
    for (const std::string& f : compile_files(p)) {
        SourceUnit u;
        CHECK(load_unit(p.base_dir + "/" + f, &u, &err));
        units.push_back(std::move(u));
    }
    CHECK(link_project(p, units, &r, &err));
    CHECK(r.scopes.size() == 1);
    const LinkResult::PouScope& main = r.scopes[0];
    const auto it = main.fb_instances.find("t");
    CHECK(it != main.fb_instances.end());
    CHECK(it->second.fields.size() == 4);
    CHECK(it->second.fields[0].name == "in" && it->second.fields[0].type == TypeKind::Bool);
    CHECK(it->second.fields[1].name == "pt" && it->second.fields[1].type == TypeKind::Time);
    CHECK(it->second.fields[2].name == "q" && it->second.fields[2].type == TypeKind::Bool);
    CHECK(it->second.fields[3].name == "et" && it->second.fields[3].type == TypeKind::Time);
    return true;
}

int main() {
    if (!test_case09()) return 1;
    if (!test_neg_cases()) return 1;
    if (!test_case16()) return 1;
    if (!test_case19()) return 1;
    if (!test_line1()) return 1;
    if (!test_builtin()) return 1;
    std::printf("linker_test: %d checks passed\n", g_checks);
    return 0;
}