/*
 * stolen from 
 * contrib/hstore/hstore_io.c
 */
#include "postgres.h"

#include "catalog/pg_type.h"
#include "funcapi.h"
#include "lib/stringinfo.h"
#include "utils/json.h"
#include "jsonapi.h"
#include "utils/builtins.h"

#include "json_extra.h"
#include "hstore.h"

/*
 * hstore_to_json_loose
 *
 * This is a heuristic conversion to json which treats
 * 't' and 'f' as booleans and strings that look like numbers as numbers,
 * as long as they don't start with a leading zero followed by another digit
 * (think zip codes or phone numbers starting with 0).
 */
PG_FUNCTION_INFO_V1(hstore_to_json_loose);
Datum		hstore_to_json_loose(PG_FUNCTION_ARGS);
Datum
hstore_to_json_loose(PG_FUNCTION_ARGS)
{
	HStore	   *in = PG_GETARG_HS(0);
	int			i;
	int			count = HS_COUNT(in);
	char	   *base = STRPTR(in);
	HEntry	   *entries = ARRPTR(in);
	StringInfoData tmp,
				dst;

	if (count == 0)
		PG_RETURN_TEXT_P(cstring_to_text_with_len("{}",2));

	initStringInfo(&tmp);
	initStringInfo(&dst);

	appendStringInfoChar(&dst, '{');

	for (i = 0; i < count; i++)
	{
		resetStringInfo(&tmp);
		appendBinaryStringInfo(&tmp, HS_KEY(entries, base, i), HS_KEYLEN(entries, i));
		escape_json(&dst, tmp.data);
		appendStringInfoString(&dst, ": ");
		if (HS_VALISNULL(entries, i))
			appendStringInfoString(&dst, "null");
		/* guess that values of 't' or 'f' are booleans */
		else if (HS_VALLEN(entries, i) == 1 && *(HS_VAL(entries, base, i)) == 't')
			appendStringInfoString(&dst, "true");
		else if (HS_VALLEN(entries, i) == 1 && *(HS_VAL(entries, base, i)) == 'f')
			appendStringInfoString(&dst, "false");
		else
		{
			resetStringInfo(&tmp);
			appendBinaryStringInfo(&tmp, HS_VAL(entries, base, i), HS_VALLEN(entries, i));
			if (IsValidJsonNumber(tmp.data, tmp.len))
				appendBinaryStringInfo(&dst, tmp.data, tmp.len);
			else
				escape_json(&dst, tmp.data);
		}

		if (i + 1 != count)
			appendStringInfoString(&dst, ", ");
	}
	appendStringInfoChar(&dst, '}');

	PG_RETURN_TEXT_P(cstring_to_text(dst.data));
}

PG_FUNCTION_INFO_V1(hstore_to_json);
Datum		hstore_to_json(PG_FUNCTION_ARGS);
Datum
hstore_to_json(PG_FUNCTION_ARGS)
{
	HStore	   *in = PG_GETARG_HS(0);
	int			i;
	int			count = HS_COUNT(in);
	char	   *base = STRPTR(in);
	HEntry	   *entries = ARRPTR(in);
	StringInfoData tmp,
				dst;

	if (count == 0)
		PG_RETURN_TEXT_P(cstring_to_text_with_len("{}",2));

	initStringInfo(&tmp);
	initStringInfo(&dst);

	appendStringInfoChar(&dst, '{');

	for (i = 0; i < count; i++)
	{
		resetStringInfo(&tmp);
		appendBinaryStringInfo(&tmp, HS_KEY(entries, base, i), HS_KEYLEN(entries, i));
		escape_json(&dst, tmp.data);
		appendStringInfoString(&dst, ": ");
		if (HS_VALISNULL(entries, i))
			appendStringInfoString(&dst, "null");
		else
		{
			resetStringInfo(&tmp);
			appendBinaryStringInfo(&tmp, HS_VAL(entries, base, i), HS_VALLEN(entries, i));
			escape_json(&dst, tmp.data);
		}

		if (i + 1 != count)
			appendStringInfoString(&dst, ", ");
	}
	appendStringInfoChar(&dst, '}');

	PG_RETURN_TEXT_P(cstring_to_text(dst.data));
}