#define NEEDS_TYPES

#ifdef IOBRIDGE_UNIX
    #include "iobridge_unix.h"
#endif

#undef NEEDS_TYPES

void write_be32(uint32_t value);
uint32_t read_be32();
void startup(char * program, char * args[]);
void child_send(int c);
int child_recv();
ssize_t read_line(char ** buffer, size_t * size);
void child_read(char ** buffer, uint32_t * size);
void child_write(uint8_t * buffer, uint32_t size);
void write_output(uint8_t * buffer, size_t size);
void write_error(uint8_t * buffer, size_t size);
int get_key();
void stdin_read(char ** buffer, uint32_t * size);

void * io_malloc(size_t size);
void io_free(void * ptr);
void * io_realloc(void * ptr, size_t size);

FILE_HANDLE_TYPE io_open(char *f, char *m);
void io_close(FILE_HANDLE_TYPE f);
void io_read_file(FILE_HANDLE_TYPE f, uint8_t ** buf, uint32_t * len);
void io_write_file(FILE_HANDLE_TYPE f, uint8_t * buf, uint32_t len);
uint32_t io_get_file_size(FILE_HANDLE_TYPE f);

enum { IO_SEEK_SET, IO_SEEK_CUR, IO_SEEK_END };
void io_seek_file(FILE_HANDLE_TYPE f, uint32_t off, uint8_t whence);

void io_rename(char * src, char * dst);
void io_delete(char * src);
void io_mkdir(char * src);
void io_rmdir(char * src);
void io_chdir(char * src);
void io_getcwd(char ** buffer);

unsigned long io_time();
void io_localtime(uint32_t * year, uint8_t * month, uint8_t * day, uint8_t * hour, uint8_t * minute, uint8_t * second);
void io_gmtime(uint32_t * year, uint8_t * month, uint8_t * day, uint8_t * hour, uint8_t * minute, uint8_t * second);
void io_sleep(uint32_t time);

void term_cooked();
void term_raw();

void term_flush();
void io_flush(FILE_HANDLE_TYPE f);
uint8_t get_errno();

uint8_t file_exists(char * path);

void term_bounds(uint32_t * width, uint32_t * height);

void io_handle_packet_0x25();

#define vector(type) type *

#define _internal_veccap(vec, size)         \
	do {                                    \
		if (vec) {                          \
			((size_t *)(vec))[-1] = (size); \
		}                                   \
	} while (0)

#define _internal_vecsiz(vec, size)         \
	do {                                    \
		if (vec) {                          \
			((size_t *)(vec))[-2] = (size); \
		}                                   \
	} while (0)

#define vector_capacity(vec) \
	((vec) ? ((size_t *)(vec))[-1] : (size_t)0)

#define vector_size(vec) \
	((vec) ? ((size_t *)(vec))[-2] : (size_t)0)

#define vector_empty(vec) \
	(vector_size(vec) == 0)

#define vector_grow(vec, count)                                               \
	do {                                                                      \
		const size_t cv_sz = (count) * sizeof(*(vec)) + (sizeof(size_t) * 2); \
		if (!(vec)) {                                                         \
			size_t *cv_p = io_malloc(cv_sz);                                     \
			assert(cv_p);                                                     \
			(vec) = (void *)(&cv_p[2]);                                       \
			_internal_veccap((vec), (count));                                 \
			_internal_vecsiz((vec), 0);                                       \
		} else {                                                              \
			size_t *cv_p1 = &((size_t *)(vec))[-2];                           \
			size_t *cv_p2 = io_realloc(cv_p1, (cv_sz));                          \
			assert(cv_p2);                                                    \
			(vec) = (void *)(&cv_p2[2]);                                      \
			_internal_veccap((vec), (count));                                 \
		}                                                                     \
	} while (0)

#define vector_pop_back(vec)                           \
	do {                                               \
		_internal_vecsiz((vec), vector_size(vec) - 1); \
	} while (0)

#define vector_erase(vec, i)                                   \
	do {                                                       \
		if (vec) {                                             \
			const size_t cv_sz = vector_size(vec);             \
			if ((i) < cv_sz) {                                 \
				_internal_vecsiz((vec), cv_sz - 1);            \
				size_t cv_x;                                   \
				for (cv_x = (i); cv_x < (cv_sz - 1); ++cv_x) { \
					(vec)[cv_x] = (vec)[cv_x + 1];             \
				}                                              \
			}                                                  \
		}                                                      \
	} while (0)

#define vector_free(vec)                         \
	do {                                         \
		if (vec) {                               \
			size_t *p1 = &((size_t *)(vec))[-2]; \
			io_free(p1);                            \
		}                                        \
	} while (0)

#define vector_begin(vec) \
	(vec)

#define vector_end(vec) \
	((vec) ? &((vec)[vector_size(vec)]) : NULL)

#define vector_push_back(vec, value)                    \
	do {                                                \
		size_t cv_cap = vector_capacity(vec);           \
		if (cv_cap <= vector_size(vec)) {               \
			vector_grow((vec), cv_cap + 16);            \
		}                                               \
		(vec)[vector_size(vec)] = (value);              \
		_internal_vecsiz((vec), vector_size(vec) + 1);  \
	} while (0)

vector(FILE_HANDLE_TYPE) files;
vector(uint8_t *) buffers;
vector(uint32_t) buffer_bounds;

// Packet implementations
void packet_0x01() {
    // Read a line of stdin of arbitary size.
    char * line = NULL; size_t size;
    if (!read_line(&line, &size)) {
        child_send(0x01);
        write_be32(0);
        return;
    } else {
        child_send(0x01);
        write_be32(strlen(line) + 1);
        child_write(line, strlen(line) + 1);
    }
}

void packet_0x02() {
    uint32_t len = read_be32();
    uint8_t * data;
    child_read((char **) &data, &len);
    write_output(data, len);
    io_free(data);
}

void packet_0x03() {
    uint32_t len = read_be32();
    uint8_t * data;
    child_read((char **) &data, &len);
    write_error(data, len);
    io_free(data);
}

void packet_0x04() {
    int16_t byte = get_key();
    if (byte == -1) {
        uint8_t b[] = { 0x04, 0xff, 0xff };
        child_write(b, 3);
    } else {
        uint8_t b[] = { 0x04, (uint8_t) byte, (uint8_t) (byte >> 8) };
        child_write(b, 3);
    }
}

void packet_0x05() {
    uint8_t byte = child_recv();
    write_output((char *) &byte, 1);
}

void packet_0x06() {
    uint8_t byte = child_recv();
    write_error((char *) &byte, 1);
}

void packet_0x07() {
    uint32_t len = read_be32();
    uint8_t * data;
    stdin_read((char **) &data, &len);
    write_be32(len);
    child_write((char *) data, len);
    io_free(data);
}

void packet_0x08() {
    uint32_t len = read_be32();
    uint8_t * data = (uint8_t *) io_malloc(len);
    if (data == NULL) {
        child_send(0x08);
        write_be32(0);
        return;
    }
    // linearly search buffers to see if there's a tombstone anywhere.
    for (uint32_t i = 0; i < vector_size(buffers); i++) {
        if (buffers[i] == NULL) {
            buffers[i] = data;
            buffer_bounds[i] = len;
            child_send(0x08);
            write_be32(i);
            return;
        }
    }
    vector_push_back(buffer_bounds, len);
    vector_push_back(buffers, data);
    child_send(0x08);
    write_be32(vector_size(buffers) - 1);
}

void packet_0x09() {
    uint32_t ptr = read_be32();
    if (ptr > vector_size(buffers)) 
        return;
    io_free(buffers[ptr]);
    buffers[ptr] = NULL;
    buffer_bounds[ptr] = 0;
}

void packet_0x0A() {
    uint32_t ptr = read_be32();
    uint32_t off = read_be32();
    uint32_t len = read_be32();
    if (ptr > vector_size(buffers) || off > buffer_bounds[ptr] || buffers[ptr] == NULL) {
        child_send(0x0A);
        write_be32(0);
        return;
    }

    len = len < buffer_bounds[ptr] - off ? len : buffer_bounds[ptr] - off;
    child_send(0x0A);
    write_be32(len);
    child_write((char *) buffers[ptr] + off, len);
}

void packet_0x0B() {
    uint32_t ptr = read_be32();
    uint32_t off = read_be32();
    uint32_t len = read_be32();
    uint8_t * data;
    child_read((char **) &data, &len);
    if (ptr > vector_size(buffers)) 
        return;

    if (off > buffer_bounds[ptr]) 
        return;

    if (buffers[ptr] == NULL) 
        return;

    len = len < buffer_bounds[ptr] - off ? len : buffer_bounds[ptr] - off;
    memcpy(buffers[ptr] + off, data, len);
    io_free(data);
}

void packet_0x0C() {
    uint32_t ptr = read_be32();
    if (ptr > vector_size(buffers)|| buffers[ptr] == NULL) {
        child_send(0x0C);
        write_be32(0);
        return;
    }
    child_send(0x0C);
    write_be32(buffer_bounds[ptr]);
}

void packet_0x0D() {
    uint32_t ptr = read_be32();
    uint32_t new_len = read_be32();
    if (ptr > vector_size(buffers) || buffers[ptr] == NULL) 
        return;

    uint8_t * new_buffer = (uint8_t *) io_realloc(buffers[ptr], new_len);
    buffers[ptr] = new_buffer;
    buffer_bounds[ptr] = new_len;
}

void packet_0x0E() {
    uint32_t len = read_be32();
    uint32_t mode = read_be32();
    uint8_t * data;
    child_read((char **) &data, &len);
    char mode_str[6]; int mode_ptr = 0;
    while (mode != 0) {
        if ((mode & 0xFF) != 0)
            mode_str[mode_ptr++] = mode & 0xFF;
        mode >>= 8;
    }
    mode_str[mode_ptr] = 0;

    if(data[len - 1] == 0) data[len - 1] = 0x00;

    FILE_HANDLE_TYPE file = io_open((char *) data, mode_str);
    if (file == NULL) {
        child_send(0x0E);
        write_be32(0);
        io_free(data);
        return;
    }

    // linearly search files to see if there's a tombstone anywhere.
    for (uint32_t i = 0; i < vector_size(buffers); i++) {
        if (files[i] == NULL) {
            files[i] = file;
            child_send(0x0E);
            write_be32(i);
            io_free(data);
            return;
        }
    }
    vector_push_back(files, file);
    child_send(0x0E);
    write_be32(vector_size(files) - 1);
    io_free(data);
}

void packet_0x0F() {
    uint32_t ptr = read_be32();
    if (ptr > vector_size(files) || files[ptr] == NULL) 
        return;
    io_close(files[ptr]);
    files[ptr] = NULL;
}

void packet_0x10() {
    uint32_t ptr = read_be32();
    uint32_t len = read_be32();
    if (ptr > vector_size(files) || files[ptr] == NULL) {
        child_send(0x10);
        write_be32(0);
        return;
    }

    uint8_t * data;
    io_read_file(files[ptr], &data, &len);
    child_send(0x10);
    write_be32(len);
    child_write((char *) data, len);
    io_free(data);
}

void packet_0x11() {
    uint32_t ptr = read_be32();
    uint32_t len = read_be32();
    uint8_t * data;
    child_read((char **) &data, &len);
    if (ptr > vector_size(files) || files[ptr] == NULL) 
        return;
    io_write_file(files[ptr], data, len);
    io_free(data);
}

void packet_0x12() {
    uint32_t ptr = read_be32();
    if (ptr > vector_size(files) || files[ptr] == NULL) {
        child_send(0x12);
        write_be32(0);
        return;
    }
    child_send(0x12);
    write_be32(io_get_file_size(files[ptr]));
}

void packet_0x13() {
    uint32_t ptr = read_be32();
    uint32_t off = read_be32();
    uint8_t whence = child_recv();
    if (ptr > vector_size(files) || files[ptr] == NULL) 
        return;
    switch(whence) {
        case 0: io_seek_file(files[ptr], (long)off, IO_SEEK_CUR); break;
        case 1: io_seek_file(files[ptr], -(long)off, IO_SEEK_CUR); break;
        case 2: io_seek_file(files[ptr], off, IO_SEEK_SET); break;
        case 3: io_seek_file(files[ptr], -off, IO_SEEK_END); break;
    }
}

void packet_0x14() {
    uint32_t len1 = read_be32();
    uint32_t len2 = read_be32();
    uint8_t * data1; child_read((char **) &data1, &len1);
    uint8_t * data2; child_read((char **) &data2, &len2);
    if(data1[len1 - 1] == 0) data1[len1 - 1] = 0x00;
    if(data2[len2 - 1] == 0) data2[len2 - 1] = 0x00;
    io_rename((char *) data1, (char *) data2);
    io_free(data1);
    io_free(data2);
}

void packet_0x15() {
    uint32_t len = read_be32();
    uint8_t * data; child_read((char **) &data, &len);
    if(data[len - 1] == 0) data[len - 1] = 0x00;
    io_delete((char *) data);
    io_free(data);
}

void packet_0x16() {
    uint32_t len = read_be32();
    uint8_t * data; child_read((char **) &data, &len);
    if(data[len - 1] == 0) data[len - 1] = 0x00;
    io_mkdir((char *) data);
    io_free(data);
}

void packet_0x17() {
    uint32_t len = read_be32();
    uint8_t * data; child_read((char **) &data, &len);
    if(data[len - 1] == 0) data[len - 1] = 0x00;
    io_rmdir((char *) data);
    io_free(data);
}

void packet_0x18() {
    uint32_t len = read_be32();
    uint8_t * data; child_read((char **) &data, &len);
    if(data[len - 1] == 0) data[len - 1] = 0x00;
    io_chdir((char *) data);
    io_free(data);
}

void packet_0x19() {
    char * cwd; io_getcwd(&cwd);
    if (cwd == NULL) {
        child_send(0x19);
        write_be32(0);
        return;
    }
    child_send(0x19);
    write_be32(strlen(cwd) + 1);
    child_write(cwd, strlen(cwd) + 1);
    io_free(cwd);
}

void packet_0x1A() {
    child_send(0x1A);
    unsigned long t = io_time();
    write_be32(t >> 32);
    write_be32(t & 0xFFFFFFFF);
}

void packet_0x1B() {
    child_send(0x1B);
    uint32_t year; uint8_t month, day, hour, minute, second;
    io_localtime(&year, &month, &day, &hour, &minute, &second);
    write_be32(year);
    child_send(month);
    child_send(day);
    child_send(hour);
    child_send(minute);
    child_send(second);
}

void packet_0x1C() {
    child_send(0x1C);
    uint32_t year; uint8_t month, day, hour, minute, second;
    io_gmtime(&year, &month, &day, &hour, &minute, &second);
    write_be32(year);
    child_send(month);
    child_send(day);
    child_send(hour);
    child_send(minute);
    child_send(second);
}

void packet_0x1D() {
    uint32_t time = read_be32();
    io_sleep(time);
}

void packet_0x1E() {
    term_raw();
}

void packet_0x1F() {
    term_cooked();
}

void packet_0x20() {
    uint32_t width, height;
    term_bounds(&width, &height);
    write_be32(width);
    write_be32(height);
}

void packet_0x21() {
    uint32_t ptr = read_be32();
    if (ptr > vector_size(files) || files[ptr] == NULL) 
        return;
    io_flush(files[ptr]);
}

void packet_0x22() {
    term_flush();
}

void packet_0x23() {
    child_send(0x23);
    child_send(get_errno());
}

void packet_0x24() {
    uint32_t len = read_be32();
    uint8_t * data; child_read((char **) &data, &len);
    if(data[len - 1] == 0) data[len - 1] = 0x00;
    if(file_exists((char *) data) == 0) {
        child_send(0x24);
        child_send(1);
    } else {
        child_send(0x24);
        child_send(0);
    }
    io_free(data);
}

void packet_0x25() {
    io_handle_packet_0x25();
}

void packet_0x26() {
    child_send(0x26);
    child_send(0); // Version major.
    child_send(1); // Version minor.
}

void packet_0x27() {
    child_send(0x27);
    write_be32(strlen(host) + 1);
    child_write(host, strlen(host) + 1);
}

#ifdef IOBRIDGE_UNIX
    #include "iobridge_unix.h"
#endif