#include "FluidSim/ScenarioCatalog.hpp"
#include "FluidSim/DesktopScenario.hpp"
#include <chrono>
#include <cmath>
#include <fstream>
#include <iostream>
#include <sstream>
#include <stdexcept>

using namespace fluidsim::port;
namespace {
void check(bool condition,const std::string& message) {if(!condition)throw std::runtime_error(message);}
std::string read(const std::filesystem::path& path) {
    std::ifstream file(path);std::ostringstream text;text<<file.rdbuf();return text.str();
}
void replace(std::string& text,const std::string& from,const std::string& to) {
    const auto pos=text.find(from);check(pos!=std::string::npos,"test fixture missing "+from);text.replace(pos,from.size(),to);
}
struct TemporaryDirectory {
    std::filesystem::path path=std::filesystem::temp_directory_path()/
        ("fluidsim-engine-config-"+std::to_string(std::chrono::steady_clock::now().time_since_epoch().count()));
    TemporaryDirectory() {std::filesystem::create_directory(path);}
    ~TemporaryDirectory() {std::error_code error;std::filesystem::remove_all(path,error);}
};
}
int main() {
    const auto& catalog=scenario_examples();
    check(catalog.size()>=32,"bundled engines missing");
    const auto& thumper=scenario_example("single-450");
    check(thumper.engine.carbureted && std::abs(thumper.engine.cylinder.bore-.096f)<1e-7f,
          "four-stroke units or fuel type changed");
    check(std::abs(scenario_example("yz-racing").two.idle_slide_opening-.03f)<1e-7f,
          "125 idle tune lost");
    for(const auto& e:catalog) {
        DesktopScenario s(e);s.set_controls(.35f,0,1);
        for(int i=0;i<256;++i) {
            const auto audio=s.process();
            check(std::isfinite(audio.left) && std::isfinite(audio.right),e.id+": invalid audio after TOML load");
        }
        const auto state=s.snapshot();
        check(state.rpm>0 && state.pipe_positivity_repairs==0,e.id+": startup changed");
    }

    TemporaryDirectory temp;
    const auto file=temp.path/"test.toml";
    const auto original=read(engine_directory()/"twin.toml");
    const auto reject=[&](std::string text,const std::string& expected) {
        {std::ofstream output(file);output<<text;}
        bool rejected=false;
        try {load_engine_file(file);}
        catch(const std::exception& error) {
            const std::string message=error.what();
            check(message.find("test.toml")!=std::string::npos,"diagnostic lost the file path");
            check(message.find(expected)!=std::string::npos,"unexpected diagnostic: "+message);
            rejected=true;
        }
        check(rejected,"invalid config accepted: "+expected);
    };
    auto changed=original;replace(changed,"schema_version = 2","schema_version = 99");reject(changed,"schema_version");
    changed=original;replace(changed,"bore_mm = 75.0","bore_mn = 75.0");reject(changed,"bore_mm");
    changed=original;replace(changed,"bore_mm = 75.0","bore_mm = -75.0");reject(changed,"cylinder");
    changed=original;replace(changed,"cylinders = 2","cylinders = 2.5");reject(changed,"integer");
    changed=original;replace(changed,"layout = \"inline\"","layout = \"flatbread\"");reject(changed,"layout");
    changed=original;replace(changed,"topology = \"collector\"","topology = \"american_v8\"");reject(changed,"V8");
    changed=original;replace(changed,"cells_per_meter = 50.0","cells_per_meter = 1000000");reject(changed,"cells_per_meter");
    changed=original;replace(changed,"phase_degrees = [0.0, 180.0]","phase_degrees = [0.0]");reject(changed,"phase_degrees");
    reject(original+"\n[junctions]\nmodel = \"mystery\"\n","model must be");
    reject(original+"\n[junctions]\nturning_loss = -1\n","turning_loss");
    reject(original+"\n[[junctions.branches]]\npipe=3\nleft=false\ndirection=[0,0,0]\n","nonzero");
    {
        std::ofstream output(file);
        output<<original<<"\n[junctions]\nmodel=\"characteristic\"\nturning_loss=0.5\n"
              <<"[[junctions.branches]]\npipe=3\nleft=false\ndirection=[-1,0,0]\n";
    }
    const auto directed=load_engine_file(file);
    check(directed.junctions.model=="characteristic" && directed.junctions.branches.size()==1,"junction configuration was not loaded");
    {
        DesktopScenario scenario(directed);
        for(int i=0;i<2048;++i) scenario.process();
        check(scenario.snapshot().pipe_positivity_repairs==0,"configured characteristic engine needs positivity repairs");
    }
    reject(original+"\n[unknown_section]\nvalue = 1\n","unknown field");
    reject("schema_version = [","Error");

    {std::ofstream output(file);output<<original;}
    std::filesystem::copy_file(file,temp.path/"duplicate.toml");
    bool duplicate=false;
    try {load_engine_directory(temp.path);}catch(const std::exception& error) {
        duplicate=std::string(error.what()).find("duplicate engine id")!=std::string::npos;
    }
    check(duplicate,"duplicate engine IDs accepted");
    std::cout<<catalog.size()<<" engine imports, startup smoke checks and invalid-config diagnostics passed\n";
}