#include <gtest/gtest.h>

#include "mock_arduino.h"
#include "hal.h"
#include "sim_hal.h"
#include "tmp36_sim.h"
#include "{{PROJECT_NAME}}_app.h"

// ============================================================================
// System Tests -- exercise WeatherApp with simulated sensor and hardware
//
// These tests use SimHal (simulated GPIO, timing, serial) and Tmp36Sim
// (simulated analog sensor with noise). No mocking expectations -- we
// observe real behavior through SimHal's inspection API.
// ============================================================================

class WeatherSystemTest : public ::testing::Test {
protected:
    void SetUp() override {
        mock_arduino_reset();
        sim_.setMillis(0);
    }

    SimHal sim_;
    Tmp36Sim sensor_{25.0f};  // 25 C base temperature
};

TEST_F(WeatherSystemTest, StartsAndPrintsToSerial) {
    WeatherApp app(&sim_, &sensor_);
    app.begin();

    std::string output = sim_.serialOutput();
    EXPECT_NE(output.find("WeatherApp started"), std::string::npos);
    EXPECT_NE(output.find("Temperature:"), std::string::npos);
}

TEST_F(WeatherSystemTest, InitialReadingIsReasonable) {
    Tmp36Sim exact_sensor(25.0f, 0.0f);  // zero noise
    WeatherApp app(&sim_, &exact_sensor);
    app.begin();

    EXPECT_NEAR(app.lastCelsius(), 25.0f, 1.0f);
    EXPECT_EQ(app.readCount(), 1);
}

TEST_F(WeatherSystemTest, ReadsAtTwoSecondIntervals) {
    WeatherApp app(&sim_, &sensor_);
    app.begin();
    EXPECT_EQ(app.readCount(), 1);

    // 1 second -- no new reading
    sim_.advanceMillis(1000);
    app.update();
    EXPECT_EQ(app.readCount(), 1);

    // 2 seconds -- new reading
    sim_.advanceMillis(1000);
    app.update();
    EXPECT_EQ(app.readCount(), 2);

    // 4 seconds -- another reading
    sim_.advanceMillis(2000);
    app.update();
    EXPECT_EQ(app.readCount(), 3);
}

TEST_F(WeatherSystemTest, FiveMinuteRun) {
    WeatherApp app(&sim_, &sensor_);
    app.begin();

    // Run 5 minutes at 100ms resolution
    for (int i = 0; i < 3000; ++i) {
        sim_.advanceMillis(100);
        app.update();
    }

    // 5 minutes = 300 seconds / 2 second interval = 150 readings + 1 initial
    EXPECT_EQ(app.readCount(), 151);
}

TEST_F(WeatherSystemTest, TemperatureChangeMidRun) {
    Tmp36Sim sensor(20.0f, 0.0f);  // start at 20 C, no noise
    WeatherApp app(&sim_, &sensor);
    app.begin();

    EXPECT_NEAR(app.lastCelsius(), 20.0f, 1.0f);

    // Change temperature and wait for next reading
    sensor.setBaseTemperature(35.0f);
    sim_.advanceMillis(2000);
    app.update();

    EXPECT_NEAR(app.lastCelsius(), 35.0f, 1.0f);
}

TEST_F(WeatherSystemTest, SerialOutputContainsFahrenheit) {
    Tmp36Sim exact_sensor(0.0f, 0.0f);  // 0 C = 32 F
    WeatherApp app(&sim_, &exact_sensor);
    app.begin();

    std::string output = sim_.serialOutput();
    EXPECT_NE(output.find("32"), std::string::npos)
        << "Should contain 32 F for 0 C: " << output;
}

TEST_F(WeatherSystemTest, NoisyReadingsStayInRange) {
    Tmp36Sim noisy_sensor(25.0f, 2.0f);  // +/- 2 C noise
    noisy_sensor.setSeed(42);
    WeatherApp app(&sim_, &noisy_sensor);

    for (int i = 0; i < 20; ++i) {
        sim_.setMillis(i * 2000);
        if (i == 0) app.begin(); else app.update();

        float c = app.lastCelsius();
        EXPECT_GE(c, 20.0f) << "Reading " << i << " too low: " << c;
        EXPECT_LE(c, 30.0f) << "Reading " << i << " too high: " << c;
    }
}