/*
 *	PROGRAM:	JRD Command Oriented Query Language
 *	MODULE:		help.epp
 *	DESCRIPTION:	Help module.
 *
 * The contents of this file are subject to the Interbase Public
 * License Version 1.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy
 * of the License at http://www.Inprise.com/IPL.html
 *
 * Software distributed under the License is distributed on an
 * "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
 * or implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code was created by Inprise Corporation
 * and its predecessors. Portions created by Inprise Corporation are
 * Copyright (C) Inprise Corporation.
 *
 * All Rights Reserved.
 * Contributor(s): ______________________________________.
 *
 * 2002.10.30 Sean Leyne - Removed support for obsolete "PC_PLATFORM" define
 *
 */

#include "firebird.h"
#include <stdio.h>
#include <string.h>
#include "../jrd/ibase.h"
#include "../qli/dtr.h"
#include "../qli/compile.h"
#include "../qli/parse.h"
#include "../qli/err_proto.h"
#include "../qli/help_proto.h"
#include "../qli/lex_proto.h"
#include "../jrd/gds_proto.h"

using MsgFormat::SafeArg;


const char* INDENT	= "  ";
const int COLUMN_WIDTH	= 20;
const int RIGHT_MARGIN	= 70;

#ifdef UNIX
const char* TARGET	= "help/help.fdb";
#endif

#if (defined WIN_NT)
const char* TARGET	= "help/help.fdb";
#endif

DATABASE HELP_DB = STATIC "help.fdb" RUNTIME target;

static int additional_topics(const TEXT*, const TEXT*, const TEXT*);
static void print_more(USHORT, USHORT, const TEXT**, USHORT*, const TEXT*); //, bool);
static void print_topic(USHORT, USHORT, const TEXT**, USHORT*, const TEXT*, bool);
static const TEXT* strip(const TEXT*);


void HELP_fini()
{
/**************************************
 *
 *	H E L P _ f i n i
 *
 **************************************
 *
 * Functional description
 *
 **************************************/

	if (HELP_DB) {
		COMMIT;
		FINISH;
	}
}


void HELP_help( qli_syntax* node)
{
/**************************************
 *
 *	H E L P _ h e l p
 *
 **************************************
 *
 * Functional description
 *	Give the poor sucker help.
 *
 **************************************/
	TEXT target[MAXPATHLEN];

	if (!HELP_DB) {
		gds__prefix(target, TARGET);
		READY
		ON_ERROR
			ERRQ_database_error(NULL, gds_status);
		END_ERROR;
		START_TRANSACTION;
	}

	USHORT max_level = 0;
	const TEXT* topics[16];
	const TEXT** topic = topics;
	*topic++ = "QLI";

	qli_name** ptr;
	qli_name** end;
	for (ptr = (qli_name**) node->syn_arg, end = ptr + node->syn_count; ptr < end; ptr++)
	{
		*topic++ = (*ptr)->nam_string;
	}

	print_topic(0, node->syn_count, topics, &max_level, "", false);

	if (max_level < node->syn_count)
		print_topic(0, node->syn_count, topics, &max_level, "", true);
}


static int additional_topics( const TEXT* parent, const TEXT* banner, const TEXT* string)
{
/**************************************
 *
 *	a d d i t i o n a l _ t o p i c s
 *
 **************************************
 *
 * Functional description
 *	Print a list of other known topics.
 *
 **************************************/
	TEXT line[256];

/* Print list of know topics.  When we find the first,
   print the banner, if any */

	TEXT* ptr = line;
	USHORT topics = 0;
	USHORT l = strlen(parent);

	FOR X IN TOPICS
		WITH X.PARENT EQ parent SORTED BY X.TOPIC
		if (QLI_abort)
			return 0;
		const TEXT* p = X.TOPIC;
		while (*p && *p != ' ')
			p++;
		if (!(l = p - X.TOPIC))
			continue;
		if (++topics == 1 && banner)
			printf("%s%s%s\n", banner, string, parent);
		p =
			line +
			((ptr - line + COLUMN_WIDTH - 1) / COLUMN_WIDTH) * COLUMN_WIDTH;
		if (p + l > line + RIGHT_MARGIN) {
			*ptr = 0;
			printf("%s%s\n", INDENT, line);
			p = ptr = line;
		}
		while (ptr < p)
			*ptr++ = ' ';
		p = X.TOPIC;
		do {
			*ptr++ = *p++;
		} while (--l);
		*ptr++ = ' ';
	END_FOR;

	if (ptr != line) {
		*ptr = 0;
		printf("%s%s\n", INDENT, line);
	}

	return topics;
}


static void print_more(USHORT level,
					   USHORT depth,
					   const TEXT** topics,
					   USHORT* max_level,
					   const TEXT* parent)
					   //bool error_flag) // unused
{
/**************************************
 *
 *	p r i n t _ m o r e
 *
 **************************************
 *
 * Functional description
 *	We have printed a topic with additional sub-topics.  Ask the user if he
 *	wants more.
 *
 **************************************/
	TEXT buffer[256], topic[80], prompt[80];

	ERRQ_msg_get(502, prompt, sizeof(prompt));	/* Msg502 "Subtopic? "  */

// Prompt the user for a line

	if (!LEX_get_line(prompt, buffer, sizeof(buffer)))
		return;

// Upcase the response and zap the blanks
	TEXT* p = topic;
	topics[1] = p;

	for (const TEXT* q = buffer; *q && *q != '\n'; q++)
		if (*q != ' ')
			*p++ = UPPER(*q);
	*p = 0;

// If we got anything, print the new topic

	if (p != topic)
	{
		print_topic(level + 1, depth + 1, topics + 1, max_level, parent, false);
		// strange, it doesn't use error_flag
	}
}


static void print_topic(USHORT level,
						USHORT depth,
						const TEXT** topics,
						USHORT* max_level, const TEXT* parent, bool error_flag)
{
/**************************************
 *
 *	p r i n t _ t o p i c
 *
 **************************************
 *
 * Functional description
 *	Lookup topic in path.  If we find a topic, and are not level
 *	zero, recurse.  Otherwise print out the topic.  In any case,
 *	remember the lowest level on which a topic was found.  If the
 *	error flag is set, print out a list of sub-topics.
 *
 **************************************/
	TEXT string[128], banner[128], buffer[128], prompt[80];

// Copy the parent string inserting a blank at the end

	TEXT* p = string;

	if (*parent) {
		const TEXT* q = parent;
		while (*q)
			*p++ = *q++;
		*p++ = ' ';
	}

	TEXT* const next = p;
	USHORT count = 0;

	FOR X IN TOPICS
		WITH X.FACILITY EQ "QLI" AND
		(X.TOPIC STARTING WITH * topics AND X.PARENT EQ parent) OR
         (X.TOPIC = X.FACILITY AND X.TOPIC = *topics AND X.TOPIC = X.PARENT)
        count++;
	END_FOR;

	if (count > 1)
		ERRQ_msg_put(80, SafeArg() << count << *topics);	/* Msg80 [%d topics matched %s] */

	count = 0;

	FOR(LEVEL level) X IN TOPICS
		WITH X.FACILITY EQ "QLI" AND
		(X.TOPIC STARTING WITH * topics AND X.PARENT EQ parent) OR
        (X.TOPIC = X.FACILITY AND X.TOPIC = *topics AND X.TOPIC = X.PARENT)
		SORTED BY X.TOPIC

        if (QLI_abort)
			  return;

		if (count) {
			ERRQ_msg_get(503, prompt, sizeof(prompt));
			/* Msg503 "\ntype <cr> for next topic or <EOF> to stop: " */
			if (!LEX_get_line(prompt, buffer, sizeof(buffer)))
				return;
		}
		++count;
		if (level > *max_level)
			*max_level = level;
		p = next;
		const TEXT* q = X.TOPIC;
		while (*q && *q != ' ')
			*p++ = *q++;
		*p = 0;
		if (level < depth)
			print_topic(level + 1, depth, topics + 1, max_level, string, error_flag);
		else {
			printf("\n%s\n\n", strip(string));
			QLI_skip_line = true;
			FOR B IN X.TEXT
				if (QLI_abort)
					return;
				B.SEGMENT[B.LENGTH] = 0;
				printf("%s%s", INDENT, B.SEGMENT);
			END_FOR;
			ERRQ_msg_format(81, sizeof(banner), banner, SafeArg() << INDENT);
			// Msg81 %sSub-topics available:
			if (additional_topics(string, banner, INDENT))
				print_more(level, depth, topics, max_level, string); //, error_flag);
		}
	END_FOR;

	if (!count && error_flag && level > *max_level) {
		const TEXT* path = strip(parent);
		ERRQ_msg_put(82, SafeArg() << path << *topics);	// Msg82 No help is available for %s %s
		ERRQ_msg_format(83, sizeof(banner), banner, SafeArg() << path);
		// Msg83 Sub-topics available for %s are:
		additional_topics(parent, banner, path);
	}
}


static const TEXT* strip( const TEXT* string)
{
/**************************************
 *
 *	s t r i p
 *
 **************************************
 *
 * Functional description
 *	Strip off the first topic in the path.
 *
 **************************************/
	const TEXT* p = string;

	while (*p != ' ')
		if (!*p++)
			return string;

	while (*p == ' ')
		if (!*p++)
			return string;

	return p;
}