#include "parse.h"
#include <ivy/ident.h>
#include <ivy/selector.h>
#include <ivy/asm/bin.h>
#include <ivy/asm/assembler.h>

struct constpool_parser_state {
	struct parser_state s_base;
	unsigned int s_prev_token;
	
	enum ivy_assembler_pval_type s_current_pval_type;

	union {
		struct ivy_selector *sel;
		struct ivy_ident *ident;
		struct ivy_asm_token *tok;
	} s_current_pval_val;

	bool s_current_index_set;
	unsigned int s_current_index;
};

static enum ivy_status parse_linefeed(struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct constpool_parser_state *state = (struct constpool_parser_state *)asm_parser_get_state(ctx);
	struct ivy_bin_constpool_table_entry entry = {0};
	
	state->s_prev_token = IVY_ASM_TOK_LINEFEED;
	
	if (!state->s_current_index_set) {
		/* no index set */
		return IVY_OK;
	}

	struct ivy_asm_token *tmp = NULL;

	switch (state->s_current_pval_type) {
	case IVY_ASM_PVAL_IDENT:
		entry.e_type = b_i32_htob(IVY_CONSTPOOL_TABLE_IDENT);
		entry.e_ex_handle = b_i32_htob(ivy_assembler_put_pval(ctx->p_assembler, IVY_ASM_PVAL_IDENT, state->s_current_index, state->s_base.s_previous_value));
		ivy_ident_destroy(state->s_base.s_previous_value);
		break;
	case IVY_ASM_PVAL_ATOM:
		tmp = state->s_base.s_previous_value;
		entry.e_type = b_i32_htob(IVY_CONSTPOOL_TABLE_ATOM);
		entry.e_ex_handle = b_i32_htob(ivy_assembler_put_pval(ctx->p_assembler, IVY_ASM_PVAL_ATOM, state->s_current_index, tmp->t_str));
		ivy_asm_token_destroy(tmp);
		break;
	case IVY_ASM_PVAL_SINT:
		entry.e_type = b_i32_htob(IVY_CONSTPOOL_TABLE_INT);
		entry.e_int = b_i32_htob(state->s_current_pval_val.tok->t_int.v);
		break;
	case IVY_ASM_PVAL_UINT:
		entry.e_type = b_i32_htob(IVY_CONSTPOOL_TABLE_UINT);
		entry.e_int = b_i32_htob(state->s_current_pval_val.tok->t_int.uv);
		break;
	case IVY_ASM_PVAL_SELECTOR:
		entry.e_type = b_i32_htob(IVY_CONSTPOOL_TABLE_SELECTOR);
		entry.e_ex_handle = b_i32_htob(ivy_assembler_put_pval(ctx->p_assembler, IVY_ASM_PVAL_SELECTOR, state->s_current_index, state->s_base.s_previous_value));
		ivy_selector_destroy(state->s_base.s_previous_value);
		break;
	case IVY_ASM_PVAL_STRING:
		tmp = state->s_current_pval_val.tok;
		entry.e_type = b_i32_htob(IVY_CONSTPOOL_TABLE_STRING);
		entry.e_ex_handle = b_i32_htob(ivy_assembler_put_pval(ctx->p_assembler, IVY_ASM_PVAL_STRING, state->s_current_index, tmp->t_str));
		ivy_asm_token_destroy(tmp);
		break;
	default:
		return IVY_ERR_BAD_SYNTAX;
	}

	state->s_current_index = 0;
	state->s_current_index_set = false;
	state->s_current_pval_type = IVY_ASM_PVAL_NONE;
	state->s_base.s_previous_value = NULL;

	return IVY_OK;
}

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

	if (state->s_prev_token == IVY_ASM_SYM_COLON) {
		/* this is a const value. */
		state->s_current_pval_type = IVY_ASM_PVAL_UINT;
		state->s_current_pval_val.tok = tok;
		state->s_prev_token = IVY_ASM_TOK_INT;
		return IVY_OK;
	}

	if (!state->s_current_index_set) {
		state->s_current_index = tok->t_int.uv;
		state->s_current_index_set = true;
		state->s_prev_token = IVY_ASM_TOK_INT;
		return IVY_OK;
	}

	/* not sure what this is but we aren't expecting it. */
	return IVY_ERR_BAD_SYNTAX;
}

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

	if (state->s_prev_token != IVY_ASM_TOK_INT) {
		/* not expected at this time */
		return IVY_ERR_BAD_SYNTAX;
	}

	state->s_prev_token = IVY_ASM_SYM_COLON;

	return IVY_OK;
}

static enum ivy_status parse_string(
	struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct constpool_parser_state *state = (struct constpool_parser_state *)asm_parser_get_state(ctx);
	
	if (state->s_prev_token != IVY_ASM_SYM_COLON) {
		return IVY_ERR_BAD_SYNTAX;
	}

	state->s_current_pval_type = IVY_ASM_PVAL_STRING;
	state->s_current_pval_val.tok = tok;
	state->s_prev_token = IVY_ASM_TOK_STRING;
	
	return IVY_OK;
}

static enum ivy_status parse_atom(
	struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct constpool_parser_state *state = (struct constpool_parser_state *)asm_parser_get_state(ctx);
	
	if (state->s_prev_token != IVY_ASM_SYM_COLON) {
		return IVY_ERR_BAD_SYNTAX;
	}

	state->s_current_pval_type = IVY_ASM_PVAL_ATOM;
	state->s_current_pval_val.tok = tok;
	state->s_prev_token = IVY_ASM_KW_ATOM;
	
	return IVY_OK;
}

static enum ivy_status parse_kw_ident(
	struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct constpool_parser_state *state = (struct constpool_parser_state *)asm_parser_get_state(ctx);
	
	if (state->s_prev_token != IVY_ASM_SYM_COLON) {
		return IVY_ERR_BAD_SYNTAX;
	}

	state->s_current_pval_type = IVY_ASM_PVAL_IDENT;
	state->s_current_pval_val.tok = tok;
	state->s_prev_token = IVY_ASM_KW_IDENT;
	
	return IVY_OK;
}

static enum ivy_status parse_selector(
	struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct constpool_parser_state *state = (struct constpool_parser_state *)asm_parser_get_state(ctx);
	
	if (state->s_prev_token != IVY_ASM_SYM_COLON) {
		return IVY_ERR_BAD_SYNTAX;
	}

	state->s_current_pval_type = IVY_ASM_PVAL_SELECTOR;
	state->s_prev_token = IVY_ASM_KW_SELECTOR;

	return IVY_OK;
}

static enum ivy_status parse_end(
	struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct constpool_parser_state *state = (struct constpool_parser_state *)asm_parser_get_state(ctx);
	
	if (state->s_current_index_set) {
		return IVY_ERR_BAD_SYNTAX;
	}

	asm_parser_pop_state(ctx, NULL);

	return IVY_OK;
}

static enum ivy_status parse_left_paren(
	struct ivy_asm_parser *ctx, struct ivy_asm_token *tok)
{
	struct constpool_parser_state *state = (struct constpool_parser_state *)asm_parser_get_state(ctx);
	
	switch (state->s_prev_token) {
	case IVY_ASM_KW_SELECTOR:
		asm_parser_push_state(ctx, ASM_PARSER_SELECTOR);
		break;
	case IVY_ASM_KW_IDENT:
		asm_parser_push_state(ctx, ASM_PARSER_IDENT);
		break;
	case IVY_ASM_KW_ATOM:
		asm_parser_push_state(ctx, ASM_PARSER_ATOM);
		break;
	default:
		return IVY_ERR_BAD_SYNTAX;
	}

	return IVY_OK;
}

static void init_state(struct ivy_asm_parser *ctx, struct parser_state *state)
{
	ivy_assembler_begin_scope(ctx->p_assembler, IVY_ASM_SCOPE_CONSTPOOL, NULL);
}

static void finish_state(struct ivy_asm_parser *ctx, struct parser_state *state)
{
	ivy_assembler_end_scope(ctx->p_assembler);
}

struct parser_state_type constpool_parser_state_type = {
	.n_init_state = init_state,
	.n_finish_state = finish_state,
	.n_state_size = sizeof(struct constpool_parser_state),
	.n_token_parsers = {
		TOK_PARSER(INT, parse_int),
		TOK_PARSER(STRING, parse_string),
		TOK_PARSER(LINEFEED, parse_linefeed),
	},
	.n_symbol_parsers = {
		SYM_PARSER(COLON, parse_colon),
		SYM_PARSER(LEFT_PAREN, parse_left_paren),
	},
	.n_keyword_parsers = {
		KW_PARSER(IDENT, parse_kw_ident),
		KW_PARSER(SELECTOR, parse_selector),
		KW_PARSER(ATOM, parse_atom),
		KW_PARSER(END, parse_end),
	}
};