#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string.h>
#include <sys/types.h>
#include "control.h"
#include "io.h"
#include "bsp_driver_sd.h"
#include "profiling.h"

// The top 4 address bits determine which device is used. (16 pages, 256 devices)
// 0xFF means that the device does not exist
// WATCH OUT THE DEVICE ADDRESS NEED TO BE REVERSED (MSB IS ON THE RIGHT)
uint8_t memory_map_0[16] = {0b00010000, 0b10001000, 0b01001000, 0b11001000, 0b00101000, 0b10101000, 0b01101000, 0b11101000, 0b00011000, 0b10011000, 0b01011000, 0b11011000, 0b00111000, 0b10111000, 0b01111000, 0b11111000};
uint8_t memory_map_1[16] = {0b00001000, 0b10001000, 0b01001000, 0b11001000, 0b00101000, 0b10101000, 0b01101000, 0b11101000, 0b00011000, 0b10011000, 0b01011000, 0b11011000, 0b00111000, 0b10111000, 0b01111000, 0b11111000};

Control control;

extern UART_HandleTypeDef huart2;
extern uint8_t ack[1];
extern uint8_t nack[1];

#define CPM_RECORD_SIZE 128
#define CPM_RECODS_PER_BLOCK 128
#define CPM_BLOCK_SIZE CPM_RECORD_SIZE*CPM_RECODS_PER_BLOCK

uint8_t get_device(uint16_t address) {
	uint8_t page = address >> 12;
	if (control.memory_config == 0) {
		return memory_map_0[page];
	} else if (control.memory_config == 1) {
		return memory_map_1[page];
	}

	return 0xFF;
}

void control_program_eeprom(uint8_t* data, uint16_t length) {
	// Take control of the bus
	send_busrq(1);
	while (!has_busak()) {
		control_cycle();
	}

	enable_address_out(1);

	select_device(memory_map_0[0]);

	for (uint16_t i = 0; i < length; ++i) {
		write_address(i);
		write_data(data[i]);

		enable_data_out(1);
		send_memrq(1);
		send_wr(1);

		send_wr(0);
		enable_data_out(0);
		send_rd(1);

		for (;;) {
			uint8_t d = read_data();
			if (d == data[i]) {
				break;
			}
		}

		send_rd(0);
		send_memrq(0);

		uint8_t progress[] = {(i+1) & 0xFF, (i+1) >> 8};
		HAL_UART_Transmit(&huart2, progress, sizeof(progress), HAL_MAX_DELAY);
	}

	enable_address_out(0);

	// Release the bus again
	send_busrq(0);

	// Restart the z80
	control_reset();

	HAL_UART_Transmit(&huart2, ack, sizeof(ack), HAL_MAX_DELAY);
}

void handle_memrq() {
	uint16_t address = read_address();
	uint8_t device = get_device(address);
	select_device(device);
}

void handle_io_read() {
	uint8_t address = read_address() & 0xFF;

	switch (address) {
		// @todo This should be detected on startup
		// Stand in for graphics hardware
		/* case 0x03: */
		/* 	write_data(0x01); */
		/* 	break; */

		/* Stand in for the keyboard hardware */
		/* case 0x1E: */
		/* 	write_data(char_c); */
		/* 	char_r = 0; */
		/* 	break; */

		/* Stand in for the keyboard hardware */
		/* case 0x1F: */
		/* 	#<{(| write_data(0x01 * char_r); |)}># */
		/* 	write_data(0x00); */
		/* 	break; */

		// Read byte from disk
		case 0x08:
			if (control.storage.ready && control.storage.command == 0x20) {
				write_data(control.storage.buffer[control.storage.counter]);
				control.storage.counter++;

				if (control.storage.counter >= control.storage.size) {
					control.storage.command = 0;
					control.storage.ready = 0;
				}
			} else {
				write_data(0x00);
			}
			break;

		// Check if disk is ready
		case 0x0f:
			if (control.storage.command == 0x30 && !control.storage.ready) {
				printf("Write: 0x%lx\n\r", control.storage.lba * CPM_RECORD_SIZE);
				for (int i = 0; i < 128; ++i) {
					control.storage.buffer[i] = 0x00;
				}
				control.storage.ready = 1;
			}

			if (control.storage.command == 0x20 && !control.storage.ready) {
				printf("Read: 0x%lx\n\r", control.storage.lba * CPM_RECORD_SIZE);
				FRESULT fr = f_lseek(control.storage.file, control.storage.lba * CPM_RECORD_SIZE);
				if (fr) {
					printf("File error: %i\n\r", fr);
					return;
				}

				fr = f_read(control.storage.file, control.storage.buffer, CPM_RECORD_SIZE, &control.storage.size);
				if (fr) {
					printf("File error: %i\n\r", fr);
					return;
				}

				control.storage.ready = 1;
			}

			write_data(0x08*control.storage.ready);
			break;

		default: {
			/* uint8_t value = read_data(); */
			/* #<{(| if (value == 0) { |)}># */
			/* 	printf("IO Read: %.2X @ %.2X\n\r", value, address); */
			/* #<{(| } |)}># */
			return;
		}
	}

	enable_data_out(1);
}

void handle_io_write() {
	uint8_t address = read_address() & 0xFF;
	uint8_t value = read_data();

	switch (address) {
		case 0x00:
			control.memory_config = 0;
			break;

		case 0x01:
			control.memory_config = 1;
			break;

		case 0x02:
			printf("%c", value);
			break;

		// Write byte to disk
		case 0x08:
			if (control.storage.ready && control.storage.command == 0x30) {
				control.storage.buffer[control.storage.counter] = value;
				control.storage.counter++;

				// Commit changes
				if (control.storage.counter == CPM_RECORD_SIZE) {
					FRESULT fr = f_lseek(control.storage.file, control.storage.lba * CPM_RECORD_SIZE);
					if (fr) {
						printf("File error: %i\n\r", fr);
						return;
					}

					unsigned int bytes_written;
					fr = f_write(control.storage.file, control.storage.buffer, CPM_RECORD_SIZE, &bytes_written);
					if (fr) {
						printf("File error: %i\n\r", fr);
						return;
					}

					if (control.storage.lba >= 0x100 && control.storage.lba < 0x180) {
						for (int i = 0; i < 4; ++i) {
							DiskEntry entry;

							entry.user = control.storage.buffer[32*i + 0];
							printf("User: %i\n\r", entry.user);

							for (int j = 0; j < 8; ++j) {
								char c = control.storage.buffer[32*i + 1 + j];
								if (c == ' ') {
									c = 0x00;
								}
								entry.name[j] = c;
							}
							printf("Name: %.8s\n\r", entry.name);

							for (int j = 0; j < 3; ++j) {
								char c = control.storage.buffer[32*i + 9 + j];
								if (c == ' ') {
									c = 0x00;
								}
								entry.ext[j] = c;
							}
							printf("Ext: %.3s\n\r", entry.ext);

							entry.size = control.storage.buffer[32*i + 15];

							for (int j = 0; j < 8; ++j) {
								uint16_t allocation = control.storage.buffer[32*i + 2*j + 16];
								allocation += control.storage.buffer[32*i + 2*j + 17] << 8;
								entry.allocation[j] = allocation;
								printf("Allocation: %i\n\r", allocation);
								if (j && allocation) {
									entry.size += 0x80;
								}
							}
							printf("Size: %li records (%li)\n\r", entry.size, entry.size * CPM_RECORD_SIZE);

							char filename[128];
							snprintf(filename, 128, "0:A/%.8s.%.3s", entry.name, entry.ext);
							FIL file;
							if (entry.user == 0xe5) {
								FILINFO nfo;
								fr = f_stat(filename, &nfo);
								if (fr == FR_OK) {
									printf("Removing file %s\n\r", filename);
									fr = f_unlink(filename);
									if (fr) {
										printf("File error: %i\n\r", fr);
										return;
									}
								}
							} else {
								printf("Opening %s\n\r", filename);
								fr = f_open(&file, filename, FA_WRITE | FA_CREATE_ALWAYS);
								if (fr) {
									printf("File error: %i\n\r", fr);
									return;
								}

								for (int j = 0; j < 8; ++j) {
									if (entry.allocation[j] == 0) {
										continue;
									}

									uint8_t buffer[CPM_BLOCK_SIZE] = {0};

									printf("Copying allocation %i (%i) to %s\n\r", j, entry.allocation[j], filename);

									fr = f_lseek(control.storage.file, 0x8000 + entry.allocation[j]*CPM_BLOCK_SIZE);
									if (fr) {
										printf("File error: %i\n\r", fr);
										return;
									}

									unsigned int bytes_read;
									fr = f_read(control.storage.file, buffer, entry.size * CPM_RECORD_SIZE, &bytes_read);
									if (fr) {
										printf("File error: %i\n\r", fr);
										return;
									}
									printf("Bytes read: %i\n\r", bytes_read);

									fr = f_lseek(&file, j*CPM_BLOCK_SIZE);
									if (fr) {
										printf("File error: %i\n\r", fr);
										return;
									}

									unsigned int bytes_written;
									fr = f_write(&file, buffer, bytes_read, &bytes_written);
									if (fr) {
										printf("File error: %i\n\r", fr);
										return;
									}
									printf("Bytes written: %i\n\r", bytes_written);

									f_sync(control.storage.file);
									if (fr) {
										printf("File error: %i\n\r", fr);
										return;
									}
								}

								fr = f_close(&file);
								if (fr) {
									printf("File error: %i\n\r", fr);
									return;
								}
							}
						}
						// @todo Verify that this is how it works
						// If there was a write here a file got modified
						printf("File(s) in record %li (0x%lx) changed\n\r", control.storage.lba, control.storage.lba * CPM_RECORD_SIZE);
					}

					control.storage.command = 0;
					control.storage.ready = 0;
				}
			}
			break;

		case 0x0b: {
			uint32_t temp = control.storage.lba & 0xFFFF00;
			control.storage.lba = temp + value;
			break;
		}

		case 0x0c: {
			uint32_t temp = control.storage.lba & 0xFF00FF;
			control.storage.lba = temp + (value << 8);
			break;
		}

		case 0x0d: {
			uint32_t temp = control.storage.lba & 0x00FFFF;
			control.storage.lba = temp + (value << 16);
			break;
		}

		// Receive disk command
		case 0x0f: {
			control.storage.ready = 0;
			control.storage.counter = 0;
			control.storage.command = value;
			break;
		}

		default:
			printf("IO Write: %.2X @ %.2X\n\r", value, address);
			break;
	}
}

void handle_ioreq() {
		if (has_wr()) {
			handle_io_write();
		} else if (has_rd()) {
			handle_io_read();
		}
}

void control_cycle() {
	set_clock(1);

	// We need this not detect IO multiple times
	static uint8_t had_ioreq = 0;
	if (!has_ioreq()) {
		had_ioreq = 0;
	}

	// @todo We are forgetting to set this somewhere
	enable_data_out(0);

	if (has_memrq()) {
		handle_memrq();
	} else if (has_ioreq() && !has_m1()) {
		had_ioreq++;
		if (had_ioreq == 3) {
			handle_ioreq();
		}
	} else if (has_ioreq() && has_m1()) {
		printf("Interrupt ackknowledged\n\r");
	}

	set_clock(0);
}

void copy_file_to_image(char* filename, FIL* disk, uint32_t source, uint32_t destination, uint32_t size) {
	FIL file;
	FRESULT fr = f_open(&file, filename, FA_READ);
	if (fr) {
		printf("File error: %i\n\r", fr);
		return;
	}

	fr = f_lseek(&file, source);
	if (fr) {
		printf("File error: %i\n\r", fr);
		return;
	}

	uint8_t* buffer = malloc(size);
	unsigned int bytes_read;
	fr = f_read(&file, buffer, size, &bytes_read);
	if (fr) {
		printf("File error: %i\n\r", fr);
		return;
	}

	fr = f_lseek(disk, destination);
	if (fr) {
		printf("File error: %i\n\r", fr);
		return;
	}

	printf("copying: %s %lx @ %lx (%i)\n\r", filename, source, destination, bytes_read);

	unsigned int bytes_written;
	fr = f_write(disk, buffer, bytes_read, &bytes_written);
	if (fr) {
		printf("File error: %i\n\r", fr);
		return;
	}

	fr = f_close(&file);
	if (fr) {
		printf("File error: %i\n\r", fr);
		return;
	}

	free(buffer);
}

DiskEntry* get_disk_entries(char* diskpath) {
	printf("Scanning: %s\n\r", diskpath);
	DiskEntry* entries = malloc(127*sizeof(DiskEntry));

	// Clear all entries
	for (int i = 0; i < 127; ++i) {
		entries[i].user = 0xe5;
		for (int j = 0; j < 8; ++j) {
			entries[i].name[j] = 0x00;
		}
		for (int j = 0; j < 3; ++j) {
			entries[i].ext[j] = 0x00;
		}
		entries[i].size = 0;
		for (int j = 0; j < 8; ++j) {
			entries[i].allocation[j] = 0x00;
		}
	}

	DIR dir;
	FILINFO fno;
	FRESULT fr = f_opendir(&dir, diskpath);
	if (fr == FR_OK) {
		uint16_t end = 1;
		uint8_t index = 0;
		for (;;) {
			fr = f_readdir(&dir, &fno);
			if (fr != FR_OK || fno.fname[0] == 0) {
				break;
			}

			if (!(fno.fattrib & AM_DIR)) {
				entries[index].user = 0x00;

				// Calculate the number of records
				uint32_t size = (fno.fsize + CPM_RECORD_SIZE - 1) / CPM_RECORD_SIZE;

				entries[index].allocation[0] = end;
				end++;

				int i = 1;
				while (size >= 0x80) {
					size -= 0x80;
					entries[index].allocation[i] = end;
					end++;
					i++;
				}

				// Store the size in the number of records
				entries[index].size = size;
				/* free(entries[index].filename); */
				entries[index].filename = strdup(fno.fname);

				uint8_t name_len = 9;
				for (uint8_t i = 0; i < 8; ++i) {
					char c = ' ';

					if (name_len == 9 && fno.fname[i] != '.') {
						c = fno.fname[i];
					} else if (name_len == 9){
						name_len = i+1;
					}

					entries[index].name[i] = c;
				}

				uint8_t done = 0;
				for (uint8_t i = 0; i < 3; ++i) {
					char c = ' ';
					
					if (!done && fno.fname[name_len+i] != 0) {
						c = fno.fname[name_len+i];
					} else {
						done = 1;
					}

					entries[index].ext[i] = c;
				}

				index++;
			}
		}
	} else {
		printf("File error: %i\n\r", fr);
		return entries;
	}


	fr = f_closedir(&dir);
	if (fr) {
		printf("File error: %i\n\r", fr);
		return entries;
	}

	return entries;
}

// @todo Properly reset everything
void control_reset() {
	free(control.storage.buffer);

	f_close(control.storage.file);
	free(control.storage.file);

	f_mount(0, "0:", 0);
	free(control.storage.fs);

	Control temp = {0, {NULL, NULL, 0, 0, 0, 0, NULL, 0}};
	control = temp;

	control.storage.buffer = (uint8_t*)malloc(CPM_RECORD_SIZE);

	control.storage.fs = (FATFS*)malloc(sizeof(FATFS));
	control.storage.file = (FIL*)malloc(sizeof(FIL));

	FRESULT fr = f_mount(control.storage.fs, "0:", 0);
	if (fr) {
		printf("File error: %i\n\r", fr);
	}

	// Open the image file
	fr = f_open(control.storage.file, "0:A.img", FA_READ | FA_WRITE | FA_CREATE_ALWAYS);
	if (fr) {
		printf("File error: %i\n\r", fr);
	}

	fr = f_chmod("0:A.img", AM_HID, 0xFF);
	if (fr) {
		printf("File error: %i\n\r", fr);
	}

	copy_file_to_image("0:loader.bin", control.storage.file, 0x00, 0x00, 0x80);
	copy_file_to_image("0:cpm22.bin", control.storage.file, 0x00, 0x80, 0x1600);
	copy_file_to_image("0:bios.bin", control.storage.file, 0x00, 0x1680, 0x600);

	f_lseek(control.storage.file, 0x8000);

	DiskEntry* entries = get_disk_entries("0:A");
	for (int i = 0; i < 127; ++i) {
		char buffer[32];

		buffer[0] = entries[i].user;
		for (int j = 0; j < 8; ++j) {
			buffer[1+j] = entries[i].name[j];
		}

		for (int j = 0; j < 3; ++j) {
			buffer[9+j] = entries[i].ext[j];
		}

		uint16_t extents = 0x00;
		for (int j = 1; j < 8; ++j) {
			if (entries[i].allocation[j]) {
				extents++;
			}
		}

		buffer[12] = extents & 0xFF;
		buffer[13] = 0x00;
		buffer[14] = (extents >> 8) & 0xFF;
		buffer[15] = entries[i].size;

		for (int j = 0; j < 8; ++j) {
			uint16_t allocation = entries[i].allocation[j];
			buffer[16 + j*2] = allocation & 0xFF;
			buffer[17 + j*2] = (allocation >> 8) & 0xFF;
		}

		unsigned int bytes_written;
		fr = f_write(control.storage.file, buffer, 32, &bytes_written);
		if (fr) {
			printf("File error: %i\n\r", fr);
			return;
		}
	}

	for (int i = 0; i < 127; ++i) {
		if (entries[i].user == 0xe5) {
			continue;
		}

		char buf[128];
		snprintf(buf, 128, "0:A/%s", entries[i].filename);
		for (int j = 0; j < 8; ++j) {
			uint16_t allocation = entries[i].allocation[j];
			if (allocation) {
				printf("allocation: %s (%i)\n\r", buf, allocation);
				copy_file_to_image(buf, control.storage.file, j*CPM_BLOCK_SIZE, 0x8000+allocation*CPM_BLOCK_SIZE, CPM_BLOCK_SIZE);
			}
		}
	}

	f_sync(control.storage.file);
	if (fr) {
		printf("File error: %i\n\r", fr);
		return;
	}

	// @todo Pretty sure we have to free things within DiskEntry
	free(entries);

	set_reset(1);
	for (int i = 0; i <= 10; ++i) {
		set_clock(i % 2);
	}
	set_reset(0);
}