#include"vartable.h"

#include"utils.h"
#include<stdlib.h>
#include<string.h>

struct ReachingDefs *reachingdefs_push(struct ReachingDefs *this) {
	struct ReachingDefs *ret = calloc(1, sizeof(*ret));
	ret->parent = this;
	return ret;
}

struct ReachingDefs *reachingdefs_coalesce(struct ReachingDefs *this) {
	struct ReachingDefs *parent = this->parent;
	if(parent) {
		parent->defs = realloc(parent->defs, sizeof(*parent->defs) * (parent->defCount + this->defCount));
		memcpy(&parent->defs[parent->defCount], this->defs, sizeof(*this->defs) * this->defCount);
		parent->defCount += this->defCount;
	}
	free(this->defs);
	free(this);
	return parent;
}

void reachingdefs_set(struct ReachingDefs *this, union AST *def) {
	this->defCount = 1;
	this->defs = realloc(this->defs, sizeof(*this->defs) * this->defCount);
	this->defs[0] = def;
	this->excludeParent = 1;
}

VarTable *vartable_new(VarTable *parent) {
	VarTable *ret = malloc(sizeof(*ret));
	ret->parent = parent;
	ret->count = 0;
	ret->names = NULL;
	ret->data = NULL;
	
	return ret;
}

VarTableEntry *vartable_get(VarTable *this, const char *name) {
	for(size_t v = 0; v < this->count; v++) {
		if(!strcmp(name, this->names[v])) return this->data[v];
	}
	return NULL;
}

VarTableEntry *vartable_find(VarTable *this, const char *name) {
	VarTable *tbl = this;
	while(tbl) {
		VarTableEntry *entry = vartable_get(tbl, name);
		if(entry) {
			return entry;
		}
		tbl = tbl->parent;
	}
	return NULL;
}

VarTableEntry *vartable_set(VarTable *this, const char *name, VarTableEntry *e) {
	this->names = realloc(this->names, sizeof(*this->names) * (this->count + 1));
	this->data = realloc(this->data, sizeof(*this->data) * (this->count + 1));
	this->names[this->count] = name;
	this->data[this->count] = e;
	this->count++;
	if(e->kind == VARTABLEENTRY_VAR) e->data.var.name = name;
	return e;
}

void vartable_new_reachingdefs_for_all_vars(VarTable *this) {
	for(size_t i = 0; i < this->count; i++) {
		if(this->data[i]->kind == VARTABLEENTRY_VAR) {
			this->data[i]->data.var.reachingDefs = reachingdefs_push(this->data[i]->data.var.reachingDefs);
		}
	}
	
	if(this->parent) {
		vartable_new_reachingdefs_for_all_vars(this->parent);
	}
}

void vartable_coalesce_reachingdefs_for_all_vars(VarTable *this) {
	for(size_t i = 0; i < this->count; i++) {
		if(this->data[i]->kind == VARTABLEENTRY_VAR) {
			this->data[i]->data.var.reachingDefs = reachingdefs_coalesce(this->data[i]->data.var.reachingDefs);
		}
	}
	
	if(this->parent) {
		vartable_coalesce_reachingdefs_for_all_vars(this->parent);
	}
}