#include <string.h>
#include <stdlib.h>
#include <mips.h>
#include <merror.h>
#include <mlimits.h>

#include "parse.h"

#define SECTBL_INIT_LEN 8
static const char inital_section[MAX_LEX_LENGTH] = "data";

int sectbl_init(struct section_table *sec_tbl)
{
	sec_tbl->len = SECTBL_INIT_LEN;
	sec_tbl->count = 0;
	sec_tbl->sections = malloc(sizeof(struct section) * SECTBL_INIT_LEN);

	if (sec_tbl->sections == NULL) {
		ERROR("cannot alloc");
		return M_ERROR;
	}

	if (sectbl_alloc(sec_tbl, &sec_tbl->current, inital_section))
		return M_ERROR;

	return M_SUCCESS;
}

void sectbl_free(struct section_table *sec_tbl)
{
	for (uint32_t i = 0; i < sec_tbl->count; i++) {
		free(sec_tbl->sections[i].entries);
	}
	free(sec_tbl->sections);
}

struct section_settings {
	const char *name;
	bool read;
	bool write;
	bool execute;
	uint32_t align;
};

static struct section_settings default_section_settings[] = {
	{"data",    true, true, false,  1},
	{"bss",     true, true, false,  1},
	{"rodata",  true, false, false, 1},
	{"text",    true, false, true,  4},
};

int sectbl_alloc(struct section_table *sec_tbl, struct section **sec,
		 const char name[MAX_LEX_LENGTH])
{
	if (sec_tbl->count >= sec_tbl->len) {
		sec_tbl->len *= 2;
		sec_tbl->sections = realloc(sec_tbl->sections,
			      sizeof(struct section) * sec_tbl->len);

		if (sec_tbl->sections == NULL) {
			ERROR("cannot realloc");
			return M_ERROR;
		}
	}

	struct section *temp;
	temp = &sec_tbl->sections[sec_tbl->count];
	strcpy(temp->name,name);
	temp->count = 0;
	temp->len = SECTBL_INIT_LEN;
	temp->alignment = 1;
	temp->read = true;
	temp->write = true;
	temp->execute = false;
	temp->index = sec_tbl->count;
	temp->entries = malloc(sizeof(struct section_entry) * SECTBL_INIT_LEN);

	for (int i = 0; i < 4; i++) {
		struct section_settings *set = &default_section_settings[i];
		if (strcmp(set->name, name) == 0) {
			temp->read = set->read;
			temp->write = set->write;
			temp->execute = set->execute;
			temp->alignment = set->align;
			break;
		}
	}

	if (temp->entries == NULL) {
		ERROR("cannot alloc");
		return M_ERROR;
	}

	sec_tbl->count++;

	*sec = temp;
	return M_SUCCESS;
}

int sectbl_get(struct section_table *sec_tbl, struct section **sec,
	       const char name[MAX_LEX_LENGTH])
{
	for (uint32_t i = 0; i < sec_tbl->count; i++) {
		struct section *temp = &sec_tbl->sections[i];
		if (strcmp(name, temp->name) == 0) {
			if (sec != NULL)
				*sec = temp;
			return M_SUCCESS;
		}
	}

	return M_ERROR;
}

int sec_push(struct section *section, struct section_entry entry)
{
	if (section->count >= section->len) {
		section->len *= 2;
		void *new = realloc(section->entries,
			 sizeof(struct section_entry) * section->len);

		if (new == NULL) {
			ERROR("cannot realloc");
			return M_ERROR;
		}

		section->entries = new;
	}

	section->entries[section->count++] = entry;

	return M_SUCCESS;
}

size_t sec_size(struct section *sec)
{
	size_t n = 0;
	for (uint32_t i = 0; i < sec->count; i++) {
		size_t t = sec->entries[i].size;
		size_t m = t % sec->alignment;
		if (m)
			t += sec->alignment - m;
		n += t;
	}
	return n;
}

size_t sec_index(struct section *sec, uint32_t idx)
{
	size_t n = 0;
	for (uint32_t i = 0; i < idx; i++) {
		size_t t = sec->entries[i].size;
		size_t m = t % sec->alignment;
		if (m)
			t += sec->alignment - m;
		n += t;
	}
	return n;
}