#include "../includes/woody.h"

t_payload *get_payload()
{
	t_payload *payload = malloc(sizeof(t_payload));
	if (!payload)
		return NULL;
	char buffer[1024];
	int fd = open("payload", O_RDONLY);
	if (fd == -1) {
		ft_put_error("Failed to open payload");
		free(payload);
		return NULL;
	}
	payload->len = read(fd, buffer, 1024);
	if (payload->len == -1)
	{
		ft_put_error("Failed to read payload");
		free(payload);
		close(fd);
		return NULL;
	}
	close(fd);
	payload->payload = malloc(sizeof(char) * payload->len);
	if (!payload->payload)
	{
		ft_put_error("Allocation error");
		free(payload);
		return NULL;
	}
	ft_memcpy(payload->payload, buffer, payload->len);
	return payload;
}

int	insert_payload(t_elf_content *woody, t_payload *payload, size_t payload_position, unsigned int e_entry, unsigned int p_offset, unsigned int p_memsz)
{
	char *ptr_jmp_value = ft_strnstr_nullterminated(payload->payload, JUMP_VALUE, payload->len);
	char *ptr_woody = ft_strnstr_nullterminated(payload->payload, WOODY, payload->len);
	char *ptr_text_section = ft_strnstr_nullterminated(payload->payload, TEXT_OFFSET, payload->len);
	char *ptr_section_size = ft_strnstr_nullterminated(payload->payload, SECTION_SIZE, payload->len);
	if (ptr_jmp_value && ptr_woody && ptr_text_section && ptr_section_size)
	{
		int32_t woody_index = ptr_woody - payload->payload;
		int32_t jmp_index = ptr_jmp_value - sizeof(JUMP) - payload->payload;
		int32_t jump_value = ((payload_position + jmp_index + 5) - e_entry) * -1; // 5 = JUMP SIZE (OPCODE + 4 bytes operand)
		ft_memcpy(&payload->payload[jmp_index + 1], &jump_value, sizeof(jump_value));

		printf("jump_value = %d (%x)\n",  jump_value, jump_value);
		printf("jmp_index = %d (%x)\n",  jmp_index, jmp_index);
		printf("payload_position = %ld (%lx)\n",  payload_position, payload_position);
		printf("e_entry = %d (%x)\n",  e_entry, e_entry);

		int64_t text_index = ptr_text_section - payload->payload;
		int64_t text_value = payload_position - p_offset + woody_index;
		ft_memcpy(&payload->payload[text_index], &text_value, sizeof(text_value));

		int64_t section_index = ptr_section_size - payload->payload;
		int64_t section_value = p_memsz;
		ft_memcpy(&payload->payload[section_index], &section_value, sizeof(section_value));

		ft_memcpy(woody->file + payload_position, payload->payload, payload->len);
		return EXIT_SUCCESS;
	}
	return EXIT_FAILURE;
}