#include "ctx.h"
#include "ivy/status.h"
#include "node.h"

#include <blue/object/string.h>
#include <ivy/lang/lex.h>

struct selector_parser_state {
	struct parser_state s_base;
	unsigned int s_prev;
	bool s_complete;
};

#define CHECK_SELECTOR_COMPLETE()						\
	do {									\
		if (state->s_complete) {					\
			parser_pop_state(ctx, STATE_ADD_NODE_TO_PARENT);	\
			return PARSE_RESULT(IVY_OK, PARSE_REPEAT_TOKEN);	\
		}								\
	} while (0)

static struct token_parse_result parse_ident(
	struct ivy_parser *ctx, struct ivy_token *tok)
{
	struct selector_parser_state *state
		= parser_get_state(ctx, struct selector_parser_state);

	struct ivy_ast_selector_node *sel
		= (struct ivy_ast_selector_node *)state->s_base.s_node;

	CHECK_SELECTOR_COMPLETE();

	if (state->s_prev == 0) {
		/* message name */
		sel->n_msg_name = tok;
		state->s_prev = IVY_TOK_IDENT;
		state->s_complete = true;
		return PARSE_RESULT(IVY_OK, 0);
	}

	if (state->s_prev == IVY_TOK_LABEL) {
		/* internal parameter name */
		b_queue_push_back(&sel->n_arg_names, &tok->t_entry);
		state->s_prev = IVY_TOK_IDENT;
		state->s_complete = true;
		return PARSE_RESULT(IVY_OK, 0);
	}

	return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
}

static struct token_parse_result parse_label(
	struct ivy_parser *ctx, struct ivy_token *tok)
{
	struct selector_parser_state *state
		= parser_get_state(ctx, struct selector_parser_state);

	struct ivy_ast_selector_node *sel
		= (struct ivy_ast_selector_node *)state->s_base.s_node;
	
	if (state->s_prev != IVY_TOK_IDENT && state->s_prev != IVY_SYM_LEFT_PAREN) {
		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
	}

	b_queue_push_back(&sel->n_arg_labels, &tok->t_entry);
	state->s_prev = IVY_TOK_LABEL;
	state->s_complete = false;

	return PARSE_RESULT(IVY_OK, 0);
}

static struct token_parse_result parse_linefeed(
	struct ivy_parser *ctx, struct ivy_token *tok)
{
	struct selector_parser_state *state
		= parser_get_state(ctx, struct selector_parser_state);

	struct ivy_ast_selector_node *sel
		= (struct ivy_ast_selector_node *)state->s_base.s_node;

	CHECK_SELECTOR_COMPLETE();

	if (!b_queue_empty(&sel->n_arg_labels)
	    && state->s_prev != IVY_SYM_RIGHT_PAREN) {
		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
	}

	if (state->s_prev != IVY_TOK_IDENT) {
		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
	}

	parser_pop_state(ctx, STATE_ADD_NODE_TO_PARENT);
	state->s_prev = IVY_TOK_LINEFEED;
	return PARSE_RESULT(IVY_OK, 0);
}

static struct token_parse_result parse_left_paren(
	struct ivy_parser *ctx, struct ivy_token *tok)
{
	struct selector_parser_state *state
		= parser_get_state(ctx, struct selector_parser_state);

	struct ivy_ast_selector_node *sel
		= (struct ivy_ast_selector_node *)state->s_base.s_node;

	if (state->s_prev != IVY_TOK_IDENT || !b_queue_empty(&sel->n_arg_labels)) {
		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
	}

	state->s_prev = IVY_SYM_LEFT_PAREN;
	return PARSE_RESULT(IVY_OK, 0);
}

static struct token_parse_result parse_right_paren(
	struct ivy_parser *ctx, struct ivy_token *tok)
{
	struct selector_parser_state *state
		= parser_get_state(ctx, struct selector_parser_state);

	struct ivy_ast_selector_node *sel
		= (struct ivy_ast_selector_node *)state->s_base.s_node;
	
	if (state->s_prev != IVY_TOK_IDENT || b_queue_empty(&sel->n_arg_labels)) {
		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
	}

	state->s_prev = IVY_SYM_RIGHT_PAREN;
	state->s_complete = true;
	parser_pop_state(ctx, STATE_ADD_NODE_TO_PARENT);
	return PARSE_RESULT(IVY_OK, 0);
}

static struct token_parse_result parse_pipe(
	struct ivy_parser *ctx, struct ivy_token *tok)
{
	struct selector_parser_state *state
		= parser_get_state(ctx, struct selector_parser_state);

	struct ivy_ast_selector_node *sel
		= (struct ivy_ast_selector_node *)state->s_base.s_node;

	if (!b_queue_empty(&sel->n_arg_labels)
	    && state->s_prev != IVY_SYM_RIGHT_PAREN) {
		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
	}

	if (state->s_prev != IVY_TOK_IDENT) {
		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
	}

	parser_pop_state(ctx, STATE_ADD_NODE_TO_PARENT);
	return PARSE_RESULT(IVY_OK, PARSE_REPEAT_TOKEN);
}

static struct token_parse_result parse_other(
	struct ivy_parser* ctx, struct ivy_token* tok)
{
	struct selector_parser_state *state
		= parser_get_state(ctx, struct selector_parser_state);

	struct ivy_ast_selector_node *sel
		= (struct ivy_ast_selector_node *)state->s_base.s_node;

	CHECK_SELECTOR_COMPLETE();

	return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
}

static void init_state(struct ivy_parser *ctx, struct parser_state *sp)
{
	struct selector_parser_state *state = (struct selector_parser_state *)sp;
	state->s_prev = 0;
	state->s_complete = false;
}

struct ast_node_type selector_node_ops = {
        .n_init_state = init_state,
        .n_state_size = sizeof(struct selector_parser_state),
        .n_node_size = sizeof(struct ivy_ast_selector_node),
        .n_token_parsers = {
		TOK_PARSER(IDENT, parse_ident),
		TOK_PARSER(LABEL, parse_label),
		TOK_PARSER_FALLBACK(parse_other),
	},
	.n_symbol_parsers = {
		SYM_PARSER(LEFT_PAREN, parse_left_paren),
		SYM_PARSER(RIGHT_PAREN, parse_right_paren),
		SYM_PARSER(PIPE, parse_pipe),
	},
};