#include <doctest/doctest.h>

#include "system/parts.hpp"
#include "system/pin_model.hpp"
#include "system/pin_spec.hpp"
#include "system/pins.hpp"

#include <string>
#include <vector>

namespace {

// A stand-in PinModel: knows VCC (power) and CLK (clock input), has a 3-pin
// canonical layout, and says nothing about anything else.
struct FakeModel : PinModel {
    PinSpec spec_for(const std::string &name) const override {
        PinSpec s;
        if (name == "VCC") {
            s.function = PinFunction::Power;
            s.direction = PinDirection::Power;
            s.source = SpecSource::Bsdl;
        } else if (name == "CLK") {
            s.function = PinFunction::Clock;
            s.direction = PinDirection::In;
            s.source = SpecSource::Bsdl;
        }
        return s;  // else default: source == None
    }
    std::vector<std::string> layout() const override {
        return {"VCC", "CLK", "GND"};
    }
    SpecSource source() const override { return SpecSource::Bsdl; }
};

}  // namespace

TEST_CASE("apply_model materialises layout pins and sets specs where the model speaks") {
    Part part("U1");
    part.add(new Pin("VCC"));  // already present; CLK and GND are not

    FakeModel m;
    ApplyReport r = apply_model(&part, m);

    // CLK and GND materialised from layout(); VCC was already there.
    CHECK(r.materialised == 2);
    CHECK(part.exists("CLK"));
    CHECK(part.exists("GND"));
    CHECK(r.pins_total == 3);

    // Specs set only where the model speaks (VCC, CLK), not GND.
    CHECK(part.get("VCC")->spec.function == PinFunction::Power);
    CHECK(part.get("VCC")->spec.source == SpecSource::Bsdl);
    CHECK(part.get("CLK")->spec.function == PinFunction::Clock);
    CHECK(part.get("GND")->spec.source == SpecSource::None);
    CHECK(r.set == 2);
}

TEST_CASE("apply_model does not overwrite a spec the model is silent about") {
    Part part("U2");
    Pin *p = new Pin("DATA");
    p->spec.function = PinFunction::Signal;
    p->spec.source = SpecSource::Bsdl;  // a prior model wrote this
    part.add(p);

    FakeModel m;  // says nothing about DATA
    apply_model(&part, m);

    CHECK(part.get("DATA")->spec.function == PinFunction::Signal);
    CHECK(part.get("DATA")->spec.source == SpecSource::Bsdl);
}

TEST_CASE("apply_model never overwrites a higher-precedence source") {
    Part part("U3");
    Pin *p = new Pin("VCC");
    p->spec.function = PinFunction::Ground;  // user-set, deliberately != the model
    p->spec.source = SpecSource::UserOverride;
    part.add(p);

    FakeModel m;  // would set VCC = Power / Bsdl
    apply_model(&part, m);

    // UserOverride (rank 5) outranks Bsdl (rank 4): kept untouched.
    CHECK(part.get("VCC")->spec.source == SpecSource::UserOverride);
    CHECK(part.get("VCC")->spec.function == PinFunction::Ground);
}