"""Run firmware logic on the host; timing and physical I/O still need the board."""

from pathlib import Path
import shutil
import subprocess
import tempfile
import unittest

PROJECT = Path(__file__).resolve().parents[2]

ARDUINO_STUB = r'''
#pragma once
#include <algorithm>
#include <cmath>
#include <cstdint>
#include <cstring>
inline uint32_t test_time = 0;
inline int transmissions = 0;
inline uint32_t millis() { return test_time; }
inline int analogRead(uint32_t pin) { return pin == 0 ? 2014 : 1981; }
inline void analogReadResolution(int) {}
inline void pinMode(uint32_t, int) {}
inline float constrain(float v, float lo, float hi) { return std::clamp(v, lo, hi); }
struct SerialStub {
    void begin(int) {}
    template<class T> void print(T, int = 0) {}
    template<class T> void println(T) {}
};
inline SerialStub Serial;
struct GPIO_InitTypeDef { int Pin, Mode, Pull, Speed, Alternate; };
struct UART_HandleTypeDef {
    int Instance;
    struct { int BaudRate, WordLength, StopBits, Parity, Mode, HwFlowCtl, OverSampling; } Init;
    struct { int AdvFeatureInit, TxPinLevelInvert; } AdvancedInit;
};
enum { PA0, PA1, GPIO_PIN_9, GPIO_MODE_AF_PP, GPIO_NOPULL, GPIO_SPEED_FREQ_LOW,
       GPIO_AF7_USART1, GPIOA, USART1, UART_WORDLENGTH_9B, UART_STOPBITS_2,
       UART_PARITY_EVEN, UART_MODE_TX, UART_HWCONTROL_NONE, UART_OVERSAMPLING_16,
       UART_ADVFEATURE_TXINVERT_INIT, UART_ADVFEATURE_TXINV_ENABLE, INPUT_ANALOG };
inline void __HAL_RCC_GPIOA_CLK_ENABLE() {}
inline void __HAL_RCC_USART1_CLK_ENABLE() {}
inline void HAL_GPIO_Init(int, GPIO_InitTypeDef*) {}
inline void HAL_UART_Init(UART_HandleTypeDef*) {}
inline void HAL_UART_Transmit(UART_HandleTypeDef*, uint8_t*, int, int) { ++transmissions; }
'''


@unittest.skipUnless(shutil.which('g++'), 'requires a host C++ compiler')
class CartFirmwareTest(unittest.TestCase):
    def test_schedule_rollover_and_sbus_encoding(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            (root / 'Arduino.h').write_text(ARDUINO_STUB)
            source = root / 'check.cpp'
            firmware = PROJECT / 'device_firmware/cart_firmware/src/main.cpp'
            source.write_text(f'#include "{firmware}"\n' + r'''
#include <cassert>
int main() {
    test_time = UINT32_MAX - 100;
    loop(); assert(transmissions == 1);
    test_time = 1;
    loop(); assert(transmissions == 2);
    test_time += 49;
    loop(); assert(transmissions == 2);
    ++test_time;
    loop(); assert(transmissions == 3);
    assert(axisNorm(X_MID, X_FWD, X_MID, X_BACK) == 0);
    assert(axisNorm(X_FWD, X_FWD, X_MID, X_BACK) == 1);
    assert(driveToSbus(0, CH2_SPAN, CH2_DB, POWER_FWD, POWER_BACK) == SBUS_MID);
    uint16_t channels[16];
    for (int n = 0; n < 16; ++n) channels[n] = n * 127;
    uint8_t packed[25]; sbusPack(packed, channels);
    assert(packed[0] == 0x0f && packed[23] == 0 && packed[24] == 0);
    for (int n = 0; n < 16; ++n) {
        uint16_t value = 0;
        for (int b = 0; b < 11; ++b) {
            const int bit = n * 11 + b;
            value |= ((packed[1 + bit / 8] >> (bit % 8)) & 1) << b;
        }
        assert(value == channels[n]);
    }
}
''')
            binary = root / 'check'
            built = subprocess.run(['g++', '-std=c++20', '-Wall', '-Wextra', '-Werror', f'-I{root}',
                                    str(source), '-o', str(binary)], capture_output=True, text=True, timeout=15)
            self.assertEqual(built.returncode, 0, built.stderr)
            subprocess.run([str(binary)], check=True, timeout=5)