/*
 * Copyright (c) 2012 Sean Bartell
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup bithenge
 * @{
 */
/**
 * @file
 * Write a tree as JSON or other text formats.
 * @todo Allow more control over the printing style, and handle printing in
 * limited space.
 */

#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <uchar.h>
#include <bithenge/blob.h>
#include <bithenge/print.h>
#include <bithenge/tree.h>
#include "common.h"

typedef struct {
	bithenge_print_type_t type;
	bool first;
	int depth;
	char *buffer;
	size_t buffer_size;
} state_t;

static void state_printf(state_t *state, const char *format, ...)
{
	va_list ap;
	va_start(ap, format);
	if (state->buffer) {
		int rc = vsnprintf(state->buffer, state->buffer_size, format,
		    ap);
		if (rc > 0 && (size_t)rc >= state->buffer_size)
			rc = state->buffer_size - 1;
		if (rc > 0) {
			state->buffer += rc;
			state->buffer_size -= rc;
		}
	} else {
		vprintf(format, ap);
	}
	va_end(ap);
}

static errno_t print_node(state_t *, bithenge_node_t *);

static void newline(state_t *state)
{
	state_printf(state, "\n");
	for (int i = 0; i < state->depth; i++) {
		state_printf(state, "    ");
	}
}

static void increase_depth(state_t *state)
{
	state->depth++;
}

static void decrease_depth(state_t *state)
{
	state->depth--;
}

static errno_t print_internal_func(bithenge_node_t *key, bithenge_node_t *value, void *data)
{
	state_t *state = (state_t *)data;
	errno_t rc = EOK;
	if (!state->first)
		state_printf(state, ",");
	newline(state);
	state->first = false;
	bool add_quotes = state->type == BITHENGE_PRINT_JSON &&
	    bithenge_node_type(key) != BITHENGE_NODE_STRING;
	if (add_quotes)
		state_printf(state, "\"");
	rc = print_node(state, key);
	if (rc != EOK)
		goto end;
	if (add_quotes)
		state_printf(state, "\"");
	state_printf(state, ": ");
	rc = print_node(state, value);
	if (rc != EOK)
		goto end;
end:
	bithenge_node_dec_ref(key);
	bithenge_node_dec_ref(value);
	return rc;
}

static errno_t print_internal(state_t *state, bithenge_node_t *node)
{
	errno_t rc;
	state_printf(state, "{");
	increase_depth(state);
	state->first = true;
	rc = bithenge_node_for_each(node, print_internal_func, state);
	if (rc != EOK)
		return rc;
	decrease_depth(state);
	if (!state->first)
		newline(state);
	state->first = false;
	state_printf(state, "}");
	return EOK;
}

static errno_t print_boolean(state_t *state, bithenge_node_t *node)
{
	bool value = bithenge_boolean_node_value(node);
	switch (state->type) {
	case BITHENGE_PRINT_PYTHON:
		state_printf(state, value ? "True" : "False");
		break;
	case BITHENGE_PRINT_JSON:
		state_printf(state, value ? "true" : "false");
		break;
	}
	return EOK;
}

static errno_t print_integer(state_t *state, bithenge_node_t *node)
{
	bithenge_int_t value = bithenge_integer_node_value(node);
	state_printf(state, "%" BITHENGE_PRId, value);
	return EOK;
}

static errno_t print_string(state_t *state, bithenge_node_t *node)
{
	const char *value = bithenge_string_node_value(node);
	state_printf(state, "\"");
	string_iterator_t i = string_iterator(value);
	while (!string_iterator_done(&i)) {
		char32_t ch;
		errno_t rc = string_iterator_next(&i, &ch);
		if (rc != EOK)
			return rc;
		if (ch == '"' || ch == '\\') {
			state_printf(state, "\\%lc", (wint_t) ch);
		} else if (ch <= 0x1f) {
			state_printf(state, "\\u%04x", (unsigned int) ch);
		} else {
			state_printf(state, "%lc", (wint_t) ch);
		}
	}
	state_printf(state, "\"");
	return EOK;
}

static errno_t print_blob(state_t *state, bithenge_node_t *node)
{
	bithenge_blob_t *blob = bithenge_node_as_blob(node);
	aoff64_t pos = 0;
	uint8_t buffer[1024];
	aoff64_t size = sizeof(buffer);
	errno_t rc;
	state_printf(state,
	    state->type == BITHENGE_PRINT_PYTHON ? "b\"" : "\"");
	do {
		rc = bithenge_blob_read(blob, pos, (char *)buffer, &size);
		if (rc != EOK)
			return rc;
		for (aoff64_t i = 0; i < size; i++)
			state_printf(state, "\\x%02x",
			    (unsigned int)buffer[i]);
		pos += size;
	} while (size == sizeof(buffer));
	state_printf(state, "\"");
	return EOK;
}

static errno_t print_node(state_t *state, bithenge_node_t *tree)
{
	switch (bithenge_node_type(tree)) {
	case BITHENGE_NODE_INTERNAL:
		return print_internal(state, tree);
	case BITHENGE_NODE_BOOLEAN:
		return print_boolean(state, tree);
	case BITHENGE_NODE_INTEGER:
		return print_integer(state, tree);
	case BITHENGE_NODE_STRING:
		return print_string(state, tree);
	case BITHENGE_NODE_BLOB:
		return print_blob(state, tree);
	}
	return ENOTSUP;
}

/** Print a tree as text to stdout.
 * @param type The format to use.
 * @param tree The root node of the tree to print.
 * @return EOK on success or an error code from errno.h.
 */
errno_t bithenge_print_node(bithenge_print_type_t type, bithenge_node_t *tree)
{
	state_t state = { type, true, 0, NULL, 0 };
	return print_node(&state, tree);
}

/** Print a tree as text into a buffer.
 * @param[in,out] str Holds a pointer to the buffer; changed to point to the
 * null character.
 * @param[in,out] size Holds the size of the buffer; changed to hold the
 * remaining size.
 * @param type The format to use.
 * @param tree The root node of the tree to print.
 * @return EOK on success or an error code from errno.h.
 */
errno_t bithenge_print_node_to_string(char **str, size_t *size,
    bithenge_print_type_t type, bithenge_node_t *tree)
{
	state_t state = { type, true, 0, *str, *size };
	errno_t rc = print_node(&state, tree);
	*str = state.buffer;
	*size = state.buffer_size;
	return rc;
}

/** @}
 */