#include "parse.h"

#include <ivy/asm/assembler.h>
#include <ivy/asm/bin.h>
#include <ivy/asm/lex.h>
#include <ivy/selector.h>

struct selector_parser_state {
	struct parser_state s_base;
	unsigned int s_prev_token;

	unsigned int s_paren_depth;
	struct ivy_asm_token *s_prev_label;
	struct ivy_selector *s_sel;
};

static void init_state(struct ivy_asm_parser *ctx, struct parser_state *s)
{
	struct selector_parser_state *state = (struct selector_parser_state *)s;
	state->s_prev_token = IVY_ASM_SYM_LEFT_PAREN;
	ivy_selector_create(&state->s_sel);
}

static enum ivy_status parse_ident(
	struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct selector_parser_state *state
		= (struct selector_parser_state *)asm_parser_get_state(ctx);
	if (state->s_prev_token == IVY_ASM_TOK_LABEL && state->s_prev_label) {
		ivy_selector_add_arg(
			state->s_sel, state->s_prev_label->t_str, tok->t_str);
		ivy_asm_token_destroy(tok);
		ivy_asm_token_destroy(state->s_prev_label);
		state->s_prev_label = tok;
		state->s_prev_token = IVY_ASM_TOK_LABEL;
		return IVY_OK;
	}

	if (state->s_prev_token != IVY_ASM_SYM_LEFT_PAREN
	    && state->s_prev_token != IVY_ASM_SYM_HYPHEN
	    && state->s_prev_token != IVY_ASM_SYM_PLUS) {
		return IVY_ERR_BAD_SYNTAX;
	}

	ivy_selector_set_name(state->s_sel, tok->t_str);
	ivy_asm_token_destroy(tok);
	state->s_prev_token = IVY_ASM_TOK_IDENT;

	return IVY_OK;
}

static enum ivy_status parse_label(
	struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct selector_parser_state *state
		= (struct selector_parser_state *)asm_parser_get_state(ctx);
	if (state->s_prev_token != IVY_ASM_SYM_LEFT_PAREN
	    && state->s_prev_token != IVY_ASM_TOK_LABEL
	    && state->s_prev_token != IVY_ASM_SYM_HYPHEN
	    && state->s_prev_token != IVY_ASM_SYM_PLUS) {
		return IVY_ERR_BAD_SYNTAX;
	}

	if (state->s_prev_label) {
		ivy_selector_add_arg(state->s_sel, state->s_prev_label->t_str, NULL);
		ivy_asm_token_destroy(state->s_prev_label);
		state->s_prev_label = NULL;
	}

	state->s_prev_label = tok;
	state->s_prev_token = IVY_ASM_TOK_LABEL;

	return IVY_OK;
}

static enum ivy_status parse_hyphen(
	struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct selector_parser_state *state
		= (struct selector_parser_state *)asm_parser_get_state(ctx);

	if (state->s_prev_token != IVY_ASM_SYM_LEFT_PAREN) {
		return IVY_ERR_BAD_SYNTAX;
	}

	ivy_selector_set_recipient(state->s_sel, IVY_SEL_OBJECT);
	state->s_prev_token = IVY_ASM_SYM_HYPHEN;

	return IVY_OK;
}

static enum ivy_status parse_plus(
	struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct selector_parser_state *state
		= (struct selector_parser_state *)asm_parser_get_state(ctx);

	if (state->s_prev_token != IVY_ASM_SYM_LEFT_PAREN) {
		return IVY_ERR_BAD_SYNTAX;
	}

	ivy_selector_set_recipient(state->s_sel, IVY_SEL_CLASS);
	state->s_prev_token = IVY_ASM_SYM_PLUS;

	return IVY_OK;
}

static enum ivy_status parse_left_paren(
	struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct selector_parser_state *state
		= (struct selector_parser_state *)asm_parser_get_state(ctx);

	if (state->s_prev_token != IVY_ASM_TOK_IDENT) {
		return IVY_ERR_BAD_SYNTAX;
	}

	if (state->s_paren_depth > 0) {
		return IVY_ERR_BAD_SYNTAX;
	}

	state->s_paren_depth++;
	state->s_prev_token = IVY_ASM_SYM_LEFT_PAREN;

	return IVY_OK;
}

static enum ivy_status parse_right_paren(
	struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct selector_parser_state *state
		= (struct selector_parser_state *)asm_parser_get_state(ctx);

	if (state->s_prev_token != IVY_ASM_TOK_IDENT
	    && state->s_prev_token != IVY_ASM_TOK_LABEL
	    && state->s_prev_token != IVY_ASM_SYM_RIGHT_PAREN) {
		return IVY_ERR_BAD_SYNTAX;
	}

	if (state->s_prev_label) {
		ivy_selector_add_arg(state->s_sel, state->s_prev_label->t_str, NULL);
		ivy_asm_token_destroy(state->s_prev_label);
		state->s_prev_label = NULL;
	}

	if (state->s_paren_depth > 0) {
		state->s_paren_depth--;
		return IVY_OK;
	}

	asm_parser_pop_state(ctx, state->s_sel);
	return IVY_OK;
}

struct parser_state_type selector_parser_state_type = {
	.n_init_state = init_state,
	.n_state_size = sizeof(struct selector_parser_state),
	.n_token_parsers = {
		TOK_PARSER(IDENT, parse_ident),
		TOK_PARSER(LABEL, parse_label),
	},
	.n_symbol_parsers = {
		SYM_PARSER(HYPHEN, parse_hyphen),
		SYM_PARSER(PLUS, parse_plus),
		SYM_PARSER(LEFT_PAREN, parse_left_paren),
		SYM_PARSER(RIGHT_PAREN, parse_right_paren),
	},
};