#include "lex-internal.h"

static enum bshell_status string_symbol(struct bshell_lex_ctx *ctx)
{
	const struct bshell_lex_token_definition *sym = NULL;
	enum bshell_status status = read_symbol(ctx, &sym);

	if (status != BSHELL_SUCCESS) {
		return status;
	}

	handle_lex_state_transition(ctx, sym->id);

	struct bshell_lex_token *tok = NULL;

	switch (sym->id) {
	case BSHELL_SYM_DQUOTE:
		return BSHELL_SUCCESS;
	case BSHELL_SYM_DOLLAR_LEFT_PAREN:
		return push_symbol(ctx, sym->id);
	case BSHELL_SYM_DOLLAR:
		status = read_var(ctx, BSHELL_TOK_VAR, &tok);
		if (status != BSHELL_SUCCESS) {
			return status;
		}

		enqueue_token(ctx, tok);
		return status;
	case BSHELL_SYM_AT:
		status = read_var(ctx, BSHELL_TOK_VAR_SPLAT, &tok);
		if (status != BSHELL_SUCCESS) {
			return status;
		}

		enqueue_token(ctx, tok);
		return status;
	case BSHELL_SYM_DOLLAR_LEFT_BRACE:
		status = read_braced_var(ctx, BSHELL_TOK_VAR, &tok);
		if (status != BSHELL_SUCCESS) {
			return status;
		}

		enqueue_token(ctx, tok);
		return status;
	default:
		break;
	}

	return BSHELL_ERR_BAD_SYNTAX;
}

static enum bshell_status string_content(struct bshell_lex_ctx *ctx)
{
	fx_wchar c = FX_WCHAR_INVALID;
	fx_string *temp = lex_state_get_tempstr(ctx);
	set_token_start(ctx);
	fx_string_clear(temp);

	while (1) {
		c = peek_char(ctx);
		if (c == FX_WCHAR_INVALID) {
			/* EOF without end of string */
			ctx->lex_status = BSHELL_ERR_BAD_SYNTAX;
		}

		if (char_can_begin_symbol(ctx, c)) {
			break;
		}

		fx_string_append_wc(temp, c);
		set_token_end(ctx);
		advance_char(ctx);
	}

	if (fx_string_get_size(temp, FX_STRLEN_NORMAL) == 0) {
		return BSHELL_SUCCESS;
	}

	struct bshell_lex_token *tok = bshell_lex_token_create_with_string(
		BSHELL_TOK_STRING,
		fx_string_get_cstr(temp));
	enqueue_token(ctx, tok);

	return BSHELL_SUCCESS;
}

static enum bshell_status string_begin(struct bshell_lex_ctx *ctx)
{
	struct bshell_lex_token *tok = bshell_lex_token_create(BSHELL_TOK_STR_START);
	if (!tok) {
		return BSHELL_ERR_NO_MEMORY;
	}

	enqueue_token(ctx, tok);
	return BSHELL_SUCCESS;
}

static enum bshell_status string_end(struct bshell_lex_ctx *ctx)
{
	struct bshell_lex_token *tok = bshell_lex_token_create(BSHELL_TOK_STR_END);
	if (!tok) {
		return BSHELL_ERR_NO_MEMORY;
	}

	enqueue_token(ctx, tok);
	return BSHELL_SUCCESS;
}

static enum bshell_status string_pump_token(struct bshell_lex_ctx *ctx)
{
	fx_wchar c = peek_char(ctx);

	if (char_can_begin_symbol(ctx, c)) {
		return string_symbol(ctx);
	}

	return string_content(ctx);
}

static const struct bshell_lex_state_link links[] = {
	LINK_PUSH(BSHELL_SYM_DOLLAR_LEFT_PAREN, BSHELL_LEX_STATE_STATEMENT, 0),
	LINK_POP(BSHELL_SYM_DQUOTE),
	LINK_END,
};

static const unsigned int symbols[] = {
	BSHELL_SYM_DOLLAR,
	BSHELL_SYM_DOLLAR_LEFT_PAREN,
	BSHELL_SYM_DOLLAR_LEFT_BRACE,
	BSHELL_SYM_DQUOTE,
	BSHELL_SYM_NONE,
};

const struct bshell_lex_state_type lex_string_state = {
	.s_id = BSHELL_LEX_STATE_STRING,
	.s_begin = string_begin,
	.s_end = string_end,
	.s_pump_token = string_pump_token,
	.s_links = links,
	.s_symbols = symbols,
};