#include <stdlib.h>
#include <merror.h>

#include "link.h"

#define SEGTAB_INIT_SIZE 8

int segtab_init(struct segment_table *segtab)
{
	segtab->len = 0;
	segtab->size = SEGTAB_INIT_SIZE;
	segtab->entries = malloc(sizeof(struct segment_table_entry) *
				SEGTAB_INIT_SIZE);

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

	return M_SUCCESS;
}

void segtab_free(struct segment_table *segtab)
{
	for (uint32_t i = 0; i < segtab->len; i++) {
		segtab_ent_free(&segtab->entries[i]);
	}
	free(segtab->entries);
}

/* create a new entry with <seg> as its first segment part */
int segtab_push(struct segment_table *segtab, struct segment_table_entry **res,
		struct segment *seg)
{
	if (segtab->len >= segtab->size) {
		uint32_t size = segtab->size * 2;
		void *new = realloc(segtab->entries,
		      sizeof(struct segment_table_entry) * size);
		if (new == NULL) {
			PERROR("cannot relloc");
			return M_ERROR;
		}
		segtab->size = size;
		segtab->entries = new;
	}

	struct segment_table_entry ent;
	if (segtab_ent_init(&ent))
		return M_ERROR;
	ent.name = seg->name;
	ent.vaddr = seg->vaddr;
	ent.off = seg->off;

	if (segtab_ent_push(&ent, seg)) {
		segtab_ent_free(&ent);
		return M_ERROR;
	}

	segtab->entries[segtab->len] = ent;

	if (res != NULL)
		*res = &segtab->entries[segtab->len];

	segtab->len++;

	return M_SUCCESS;
}

/* find a segment table entry with a given name */
int segtab_get(struct segment_table *segtab, struct segment_table_entry **ent,
	       const char *name)
{
	for (uint32_t i = 0; i < segtab->len; i++) {
		const char *segname = segtab->entries[i].name;
		if (strcmp(name, segname) != 0)
			continue;

		*ent = &segtab->entries[i];
		return M_SUCCESS;
	}

	return M_ERROR;
}

int segtab_ent_init(struct segment_table_entry *ent)
{
	ent->len = 0;
	ent->size = SEGTAB_INIT_SIZE;
	ent->parts = malloc(sizeof(struct segment *) *
				SEGTAB_INIT_SIZE);

	if (ent->parts == NULL) {
		PERROR("cannot alloc");
		return M_ERROR;
	}

	return M_SUCCESS;
}

void segtab_ent_free(struct segment_table_entry *ent)
{
	free(ent->parts);
}

int segtab_ent_push(struct segment_table_entry *ent, struct segment *seg)
{
	if (ent->len >= ent->size) {
		uint32_t size = ent->size * 2;
		void *new = realloc(ent->parts,
		      sizeof(struct segment *) * size);
		if (new == NULL) {
			PERROR("cannot relloc");
			return M_ERROR;
		}
		ent->size = size;
		ent->parts = new;
	}

	if (ent->len > 0) {
		struct segment *first = ent->parts[0];
		if (first->align != seg->align) {
			ERROR("segment '%s' doest not have matching alignment",
				ent->name);
		}
		if (first->read != seg->read ||
			first->write != seg->write ||
			first->execute != seg->execute) {
			ERROR("segment '%s' doest not have matching RWX",
				ent->name);
		}
	} else {
		ent->off = seg->new_off;
		ent->vaddr = seg->new_vaddr;
	}

	ent->parts[ent->len++] = seg;
	return M_SUCCESS;
}

uint32_t segtab_ent_size(struct segment_table_entry *ent)
{
	uint32_t size = 0;
	for (uint32_t i = 0; i < ent->len; i++) {
		size += ent->parts[i]->size;
	}
	return size;
}