// Tests for the Nano firmware (src/nano), run on the PC: pio test -e native
//
// The real Arduino, EEPROM and display driver are replaced by the fakes in test/mocks.
// Tests push bytes into Serial.in, call loop() and check what the display was asked to do.

#include <unity.h>

#include "Arduino.h"
#include "BROSE9323.h"
#include "EEPROM.h"

#include <cstdlib>
#include <vector>

// From src/nano/main.cpp
extern BROSE9323 display;
extern uint32_t last_refresh;
void setup();
void loop();

// Send bytes to the Nano and let it process them
static void send(const std::string &data)
{
	for (char c : data)
		Serial.in.push_back(c);
	loop();
}

static bool replied(const char *text)
{
	return Serial.out.find(text) != std::string::npos;
}

void setUp()
{
	// Finish any half-received line from the previous test
	send("\n");
	fake_millis += 1;
	last_refresh = fake_millis; // no full redraw due unless a test asks for one
	display.calls.clear();
	display.direct = false;
	Serial.out.clear();
}

void tearDown() {}

// ---------------------------------------------------------------------------
// Boot
// ---------------------------------------------------------------------------

void test_boot_does_not_flip_dots()
{
	EEPROM.erase();
	setup();
	TEST_ASSERT_EQUAL(1, display.count("begin"));
	TEST_ASSERT_EQUAL(0, display.count("display"));
	TEST_ASSERT_EQUAL(0, display.count("fill"));
}

void test_boot_sends_ready()
{
	setup();
	TEST_ASSERT_TRUE(replied("READY\n"));
}

void test_boot_uses_default_flip_time_with_empty_eeprom()
{
	EEPROM.erase();
	setup();
	TEST_ASSERT_EQUAL(200, display.last("timing")->a);
}

// ---------------------------------------------------------------------------
// Commands
// ---------------------------------------------------------------------------

void test_pixel_runs_without_waiting_for_next_command()
{
	send("s0a051\n");
	TEST_ASSERT_EQUAL(1, display.count("pixel"));
	TEST_ASSERT_EQUAL(10, display.last("pixel")->a);
	TEST_ASSERT_EQUAL(5, display.last("pixel")->b);
	TEST_ASSERT_EQUAL(1, display.last("pixel")->c);
}

void test_direct_pixel_flips_immediately_and_resets_direct_mode()
{
	send("S010200\n");
	TEST_ASSERT_EQUAL(1, display.count("directPixel"));
	TEST_ASSERT_FALSE(display.direct);
}

void test_fill()
{
	send("F1\n");
	TEST_ASSERT_EQUAL(1, display.last("fill")->a);
	send("F0\n");
	TEST_ASSERT_EQUAL(0, display.last("fill")->a);
}

void test_display()
{
	send("D\n");
	TEST_ASSERT_EQUAL(1, display.count("display"));
	TEST_ASSERT_EQUAL(0, display.last("display")->a); // not forced
	TEST_ASSERT_EQUAL(0, display.last("display")->b); // with the effect
}

void test_display_instant_frame()
{
	send("D1\n");
	TEST_ASSERT_EQUAL(1, display.count("display"));
	TEST_ASSERT_EQUAL(0, display.last("display")->a);
	TEST_ASSERT_EQUAL(1, display.last("display")->b); // without the effect
}

void test_refresh_waits_for_idle_after_instant_frames()
{
	last_refresh = fake_millis;
	fake_millis += 120000;
	send("D1\n");
	TEST_ASSERT_EQUAL(1, display.count("display")); // no full redraw: more frames follow
	fake_millis += 3000;
	loop();
	TEST_ASSERT_EQUAL(2, display.count("display"));
	TEST_ASSERT_EQUAL(1, display.calls.back().a);
}

void test_lowercase_and_uppercase_commands()
{
	send("f1\nd\n");
	TEST_ASSERT_EQUAL(1, display.count("fill"));
	TEST_ASSERT_EQUAL(1, display.count("display"));
}

void test_command_split_over_several_reads_with_crlf()
{
	send("s0");
	send("1");
	send("021\r\n");
	TEST_ASSERT_EQUAL(1, display.count("pixel"));
	TEST_ASSERT_EQUAL(1, display.last("pixel")->a);
	TEST_ASSERT_EQUAL(2, display.last("pixel")->b);
}

void test_print_text_with_newline_escape()
{
	send("P0102115\\nab\n");
	TEST_ASSERT_EQUAL(1, display.last("cursor")->a);
	TEST_ASSERT_EQUAL(2, display.last("cursor")->b);
	TEST_ASSERT_EQUAL(1, display.last("textColor")->a);
	TEST_ASSERT_EQUAL(0, display.last("textColor")->b);
	TEST_ASSERT_EQUAL(1, display.last("textSize")->a);
	TEST_ASSERT_EQUAL(3, display.count("write")); // '5', 'a', 'b' and no garbage
	TEST_ASSERT_EQUAL(1, display.count("newline"));
}

void test_print_buffer()
{
	send("R\n");
	TEST_ASSERT_EQUAL(1, display.count("printBuffer"));
}

// ---------------------------------------------------------------------------
// Bitmaps
// ---------------------------------------------------------------------------

void test_bitmap_pixels()
{
	// 8x2 at (4,3), color 1, rows F0 and 81
	send("B040308021F081\n");
	const int expected[][2] = {{4, 3}, {5, 3}, {6, 3}, {7, 3}, {4, 4}, {11, 4}};
	TEST_ASSERT_EQUAL(6, display.count("pixel"));
	int i = 0;
	for (const DisplayCall &call : display.calls)
	{
		if (call.what != "pixel")
			continue;
		TEST_ASSERT_EQUAL(expected[i][0], call.a);
		TEST_ASSERT_EQUAL(expected[i][1], call.b);
		TEST_ASSERT_EQUAL(1, call.c);
		i++;
	}
}

void test_full_screen_bitmap_is_streamed()
{
	// 84x19 = 399 hex digits, much longer than the 64 character line buffer
	send("B000054131" + std::string(399, 'F') + "\n");
	TEST_ASSERT_EQUAL(84 * 19, display.count("pixel"));
}

void test_invalid_bitmap_data_is_not_run_as_commands()
{
	// width 5 is invalid; the data contains the command letters B, D and F
	send("B0000050100BDFDFDF\nD\n");
	TEST_ASSERT_TRUE(replied("ERR"));
	TEST_ASSERT_EQUAL(0, display.count("fill"));
	TEST_ASSERT_EQUAL(1, display.count("display"));
}

void test_incomplete_bitmap_header()
{
	send("B00\nD\n");
	TEST_ASSERT_TRUE(replied("ERR"));
	TEST_ASSERT_EQUAL(1, display.count("display"));
}

// ---------------------------------------------------------------------------
// Recovering from bad input
// ---------------------------------------------------------------------------

void test_too_long_line_is_rejected()
{
	send(std::string(200, 'x') + "\nF1\n");
	TEST_ASSERT_TRUE(replied("Line too long"));
	TEST_ASSERT_EQUAL(1, display.count("fill"));
}

void test_truncated_command_is_ignored()
{
	send("s01\nF1\n");
	TEST_ASSERT_EQUAL(0, display.count("pixel"));
	TEST_ASSERT_EQUAL(1, display.count("fill"));
}

void test_unknown_command_is_ignored()
{
	send("xyz\nF1\n");
	TEST_ASSERT_EQUAL(1, display.count("fill"));
}

// ---------------------------------------------------------------------------
// Flip time
// ---------------------------------------------------------------------------

void test_timing_is_applied_immediately()
{
	send("T225\n");
	TEST_ASSERT_EQUAL(225, display.last("timing")->a);
}

void test_timing_above_255_is_stored_and_restored()
{
	send("T300\n");
	TEST_ASSERT_EQUAL(300, display.last("timing")->a);
	display.calls.clear();
	setup(); // reboot
	TEST_ASSERT_EQUAL(300, display.last("timing")->a);
}

void test_timing_out_of_range_is_rejected()
{
	send("T5\n");
	send("T99999\n");
	TEST_ASSERT_EQUAL(0, display.count("timing"));
	TEST_ASSERT_TRUE(replied("ERR"));
}

// ---------------------------------------------------------------------------
// Flip gap, pulses and refresh effect
// ---------------------------------------------------------------------------

void test_defaults_with_empty_eeprom()
{
	EEPROM.erase();
	setup();
	TEST_ASSERT_EQUAL(200, display.last("gap")->a);
	TEST_ASSERT_EQUAL(2, display.last("pulses")->a);
	TEST_ASSERT_EQUAL(EFFECT_INSTANT, display.last("effect")->a);
	TEST_ASSERT_EQUAL(1500, display.last("effect")->b);
	TEST_ASSERT_EQUAL(0, display.last("effect")->c);
}

void test_eeprom_from_before_the_new_settings_keeps_flip_time()
{
	// Old firmware only stored the magic and the flip time; the rest is still 0xFF
	EEPROM.erase();
	send("T300\n");
	EEPROM.put(4, (uint16_t)0xFFFF);
	EEPROM.put(6, (uint8_t)0xFF);
	EEPROM.put(7, (uint8_t)0xFF);
	EEPROM.put(8, (uint16_t)0xFFFF);
	EEPROM.put(10, (uint8_t)0xFF);
	display.calls.clear();
	setup();
	TEST_ASSERT_EQUAL(300, display.last("timing")->a);
	TEST_ASSERT_EQUAL(200, display.last("gap")->a);
	TEST_ASSERT_EQUAL(2, display.last("pulses")->a);
	TEST_ASSERT_EQUAL(EFFECT_INSTANT, display.last("effect")->a);
}

void test_gap_is_applied_and_stored()
{
	send("G350\n");
	TEST_ASSERT_EQUAL(350, display.last("gap")->a);
	send("G0\n");
	TEST_ASSERT_EQUAL(0, display.last("gap")->a);
	send("G1200\n");
	display.calls.clear();
	setup();
	TEST_ASSERT_EQUAL(1200, display.last("gap")->a);
}

void test_gap_out_of_range_is_rejected()
{
	send("G5001\n");
	send("G\n");
	TEST_ASSERT_EQUAL(0, display.count("gap"));
	TEST_ASSERT_TRUE(replied("ERR"));
}

void test_pulses_are_applied_and_stored()
{
	send("N3\n");
	TEST_ASSERT_EQUAL(3, display.last("pulses")->a);
	send("N1\n");
	display.calls.clear();
	setup();
	TEST_ASSERT_EQUAL(1, display.last("pulses")->a);
}

void test_pulses_out_of_range_are_rejected()
{
	send("N0\n");
	send("N4\n");
	TEST_ASSERT_EQUAL(0, display.count("pulses"));
	TEST_ASSERT_TRUE(replied("ERR"));
}

void test_effect_is_applied_and_stored()
{
	send("E1,2500\n");
	TEST_ASSERT_EQUAL(EFFECT_SPARKLE, display.last("effect")->a);
	TEST_ASSERT_EQUAL(2500, display.last("effect")->b);
	display.calls.clear();
	setup();
	TEST_ASSERT_EQUAL(EFFECT_SPARKLE, display.last("effect")->a);
	TEST_ASSERT_EQUAL(2500, display.last("effect")->b);
	TEST_ASSERT_EQUAL(0, display.last("effect")->c); // no flags given
	send("E9,1000,1\n");
	TEST_ASSERT_EQUAL(EFFECT_RANDOM, display.last("effect")->a);
	TEST_ASSERT_EQUAL(EFFECT_FLAG_SMALL_ONLY, display.last("effect")->c);
	display.calls.clear();
	setup();
	TEST_ASSERT_EQUAL(EFFECT_FLAG_SMALL_ONLY, display.last("effect")->c);
	send("E0,1500,0\n");
}

void test_invalid_effect_is_rejected()
{
	send("E10,1500\n"); // unknown effect
	send("E1,1500,2\n"); // unknown flag
	send("E1,50\n");   // too fast
	send("E1\n");      // no duration
	TEST_ASSERT_EQUAL(0, display.count("effect"));
	TEST_ASSERT_TRUE(replied("ERR"));
}

void test_no_full_redraw_while_an_effect_runs()
{
	last_refresh = fake_millis;
	fake_millis += 120000;
	display.effect_running = true;
	send("D\n");
	TEST_ASSERT_EQUAL(1, display.count("display")); // only the frame itself
	display.effect_running = false;
	loop();
	TEST_ASSERT_EQUAL(2, display.count("display"));
	TEST_ASSERT_EQUAL(1, display.last("display")->a);
}

// Every effect order visits each dot exactly once
static void checkSequence(uint8_t effect, uint8_t w, uint8_t h, uint16_t seed)
{
	std::vector<int> seen(w * h, 0);
	DotSequence sequence;
	sequence.begin(effect, w, h, seed);
	uint8_t x, y;
	int n = 0;
	while (sequence.next(x, y))
	{
		TEST_ASSERT_TRUE(x < w && y < h);
		seen[y * w + x]++;
		n++;
	}
	TEST_ASSERT_EQUAL(w * h, n);
	TEST_ASSERT_EQUAL(w * h, sequence.total());
	for (int count : seen)
		TEST_ASSERT_EQUAL(1, count);
}

void test_every_effect_visits_each_dot_once()
{
	for (uint8_t effect = 0; effect < EFFECT_COUNT; effect++)
	{
		checkSequence(effect, 84, 19, 0);
		checkSequence(effect, 84, 19, 12345);
		checkSequence(effect, 7, 5, 3);
		checkSequence(effect, 5, 7, 3);
		checkSequence(effect, 1, 1, 0);
		checkSequence(effect, 1, 6, 0);
		checkSequence(effect, 6, 1, 0);
		checkSequence(effect, 2, 2, 0);
	}
	// Sparkle with every LFSR size up to 4095 dots
	for (int n = 2; n < 4096; n = n * 2 + 1)
		checkSequence(EFFECT_SPARKLE, n > 255 ? 255 : n, n > 255 ? (n + 254) / 255 : 1, 7);
}

void test_wipe_goes_left_to_right_and_center_starts_in_the_middle()
{
	DotSequence sequence;
	uint8_t x, y;
	sequence.begin(EFFECT_WIPE, 84, 19, 0);
	sequence.next(x, y);
	TEST_ASSERT_EQUAL(0, x);
	sequence.begin(EFFECT_CENTER, 84, 19, 0);
	sequence.next(x, y);
	TEST_ASSERT_EQUAL(42, x);
	sequence.begin(EFFECT_DIAGONAL, 84, 19, 0);
	sequence.next(x, y);
	TEST_ASSERT_TRUE(x == 0 && y == 0);
	sequence.next(x, y);
	TEST_ASSERT_TRUE(x == 1 && y == 0);
	sequence.next(x, y);
	TEST_ASSERT_TRUE(x == 0 && y == 1);
	// Spiral: the whole top row, then down the right side
	sequence.begin(EFFECT_SPIRAL, 84, 19, 0);
	for (int i = 0; i < 84; i++)
	{
		sequence.next(x, y);
		TEST_ASSERT_TRUE(x == i && y == 0);
	}
	sequence.next(x, y);
	TEST_ASSERT_TRUE(x == 83 && y == 1);
	sequence.begin(EFFECT_RAIN, 84, 19, 0);
	sequence.next(x, y);
	sequence.next(x, y);
	TEST_ASSERT_EQUAL(1, x);
	TEST_ASSERT_EQUAL(0, y);
}

void test_sparkle_order_is_scrambled()
{
	// Neighbouring dots should rarely follow each other
	DotSequence sequence;
	sequence.begin(EFFECT_SPARKLE, 84, 19, 99);
	uint8_t x, y, px = 0, py = 0;
	int neighbours = 0, n = 0;
	while (sequence.next(x, y))
	{
		if (n++ && abs(x - px) <= 1 && abs(y - py) <= 1)
			neighbours++;
		px = x;
		py = y;
	}
	TEST_ASSERT_LESS_THAN(n / 20, neighbours);
}

// ---------------------------------------------------------------------------
// Periodic full redraw
// ---------------------------------------------------------------------------

void test_refresh_waits_for_end_of_frame()
{
	last_refresh = fake_millis;
	fake_millis += 120000;
	send("s000001\n");
	TEST_ASSERT_EQUAL(0, display.count("display"));
	send("D\n");
	TEST_ASSERT_EQUAL(2, display.count("display"));
	TEST_ASSERT_EQUAL(1, display.calls.back().a); // forced full redraw after the frame
}

void test_refresh_only_once_per_interval()
{
	last_refresh = fake_millis;
	fake_millis += 120000;
	send("D\n");
	display.calls.clear();
	send("D\n");
	TEST_ASSERT_EQUAL(1, display.count("display"));
}

void test_refresh_when_serial_is_idle()
{
	last_refresh = fake_millis;
	fake_millis += 120000;
	loop();
	TEST_ASSERT_EQUAL(1, display.count("display"));
	TEST_ASSERT_EQUAL(1, display.last("display")->a);
}

void test_no_refresh_storm_after_millis_wraps()
{
	fake_millis = 0xFFFFFFFFu - 1000;
	last_refresh = fake_millis;
	fake_millis += 5000; // wraps past 0
	for (int i = 0; i < 5; i++)
		send("D\n");
	TEST_ASSERT_EQUAL(5, display.count("display"));

	fake_millis += 120000;
	display.calls.clear();
	send("D\n");
	TEST_ASSERT_EQUAL(2, display.count("display"));
}

int main()
{
	UNITY_BEGIN();

	RUN_TEST(test_boot_does_not_flip_dots);
	RUN_TEST(test_boot_sends_ready);
	RUN_TEST(test_boot_uses_default_flip_time_with_empty_eeprom);

	RUN_TEST(test_pixel_runs_without_waiting_for_next_command);
	RUN_TEST(test_direct_pixel_flips_immediately_and_resets_direct_mode);
	RUN_TEST(test_fill);
	RUN_TEST(test_display);
	RUN_TEST(test_display_instant_frame);
	RUN_TEST(test_refresh_waits_for_idle_after_instant_frames);
	RUN_TEST(test_lowercase_and_uppercase_commands);
	RUN_TEST(test_command_split_over_several_reads_with_crlf);
	RUN_TEST(test_print_text_with_newline_escape);
	RUN_TEST(test_print_buffer);

	RUN_TEST(test_bitmap_pixels);
	RUN_TEST(test_full_screen_bitmap_is_streamed);
	RUN_TEST(test_invalid_bitmap_data_is_not_run_as_commands);
	RUN_TEST(test_incomplete_bitmap_header);

	RUN_TEST(test_too_long_line_is_rejected);
	RUN_TEST(test_truncated_command_is_ignored);
	RUN_TEST(test_unknown_command_is_ignored);

	RUN_TEST(test_timing_is_applied_immediately);
	RUN_TEST(test_timing_above_255_is_stored_and_restored);
	RUN_TEST(test_timing_out_of_range_is_rejected);

	RUN_TEST(test_defaults_with_empty_eeprom);
	RUN_TEST(test_eeprom_from_before_the_new_settings_keeps_flip_time);
	RUN_TEST(test_gap_is_applied_and_stored);
	RUN_TEST(test_gap_out_of_range_is_rejected);
	RUN_TEST(test_pulses_are_applied_and_stored);
	RUN_TEST(test_pulses_out_of_range_are_rejected);
	RUN_TEST(test_effect_is_applied_and_stored);
	RUN_TEST(test_invalid_effect_is_rejected);
	RUN_TEST(test_no_full_redraw_while_an_effect_runs);
	RUN_TEST(test_every_effect_visits_each_dot_once);
	RUN_TEST(test_wipe_goes_left_to_right_and_center_starts_in_the_middle);
	RUN_TEST(test_sparkle_order_is_scrambled);

	RUN_TEST(test_refresh_waits_for_end_of_frame);
	RUN_TEST(test_refresh_only_once_per_interval);
	RUN_TEST(test_refresh_when_serial_is_idle);
	RUN_TEST(test_no_refresh_storm_after_millis_wraps);

	return UNITY_END();
}