#include "ufed-curses-help.h"
#include "ufed-curses.h"

#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <locale.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>


/* internal members */
static sFlag* lines = NULL;
static size_t helpheight, helpwidth;

/* internal prototypes */
static int callback(sFlag** curr, int key);
static int drawline(sFlag* line, bool highlight);
static void free_lines(void);
void help(void);
static void init_lines(void);

/* function implementations */
static void init_lines(void)
{
	static const char * const help[] = {
"--- What is ufed? ---",
"",
"ufed is a simple program designed to help you configure the systems USE "
"flags (see below) to your liking. To enable or disable a flag highlight it "
"and hit space.",
"",
"ufed edits the USE flag settings in your make.conf file only. It can not be "
"used to edit your package.use file.",
"",
"If you have two make.conf files, /etc/make.conf and /etc/portage/make.conf, "
"ufed reads the first, overrides its settings with the second, and writes "
"changes to the second.",
"",
"If /etc/portage/make.conf is a directory, ufed will parse all files in this "
"directory recursively, omitting files that begin with a '.' or end with a "
"'~', and will read all USE flag settings that can be found. Changes are "
"written to the last file found, overriding all others.",
"",
"--- What Are USE Flags? ---",
"",
"The USE settings system is a flexible way to enable or disable various "
"features at package build-time on a global level and for individual packages. "
"This allows an administrator control over how packages are built in regards "
"to the optional features which can be compiled into those packages.",
"",
"For instance, packages with optional GNOME support can have this support "
"disabled at compile time by disabling the \"gnome\" USE flag. Enabling the "
"\"gnome\" USE flag would enable GNOME support in these packages.",
"",
"The effect of USE flags on packages is dependent on whether both the "
"software itself and the package ebuild supports the USE flag as an "
"optional feature. If the software does not have support for an optional "
"feature then the corresponding USE flag will obviously have no effect.",
"",
"Also many package dependencies are not considered optional by the software "
"and thus USE flags will have no effect on those mandatory dependencies.",
"",
"A list of USE keywords used by a particular package can be found by checking "
"the IUSE line in any ebuild file.",
"",
"See",
" http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=2&chap=1",
"for more information on USE flags.",
"",
"Please also note that if ufed describes a flag as (Unknown) it generally "
"means that it is either a spelling error in one of the three configuration "
"files or it is not an officially sanctioned USE flag.",
"Sanctioned USE flags can be found in",
" /usr/portage/profiles/use.desc",
"and in",
" /usr/portage/profiles/use.local.desc",
"",
"--- What are \"global\" and \"local\" USE flags? ---",
"",
"Global USE flags are called such because they represent functionality that "
"is found in a wider variety of packages. For example, the global flag "
"\"cjk\" is about adding / not adding support for Eastern-Asian languages, "
"which affects a multitude of various packages. Global flags are described in",
" /usr/portage/profiles/use.desc.",
"",
"Local USE flags are unique package-wise, because the functionality they "
"stand for is only found in that particular package and no other.",
"See",
" /usr/portage/profiles/use.local.desc",
"for a full, per-package listing of all local USE flags.",
"",
"It still happens that a flag which is defined as global is also defined as "
"local for one or more packages. That is because the general definition of "
"the global flag takes on specialized semantics in some particular package. "
"It also occurs that multiple packages define a local flag of the same "
"name - the meaning of the flag differs, however, for each package.",
"",
"--- What are \"Masked\" and \"Forced\" flags? ---",
"",
"ufed allows to view the descriptions of flags that are either masked or "
"forced.",
"",
"If a USE flag does not apply to your system, or is highly experimental, it "
"is masked and can not be enabled.",
"",
"If a USE flag is mandatory for your system or for a specific package, it is "
"forced and can not be disabled.",
"",
"Flags that are masked or forced globally have their names displayed in "
"parentheses, and are prefixed with a '-' if they are masked. If one of these "
"flags is set in your make.conf, you can remove it with ufed.",
"",
"If a flag is only masked or forced for specific packages, a lower case 'm' "
"or 'f' in the defaults column (see \"Display layout\" below) indicates this.",
"",
"--- Navigation and control ---",
"",
"ufed will present you with a list of descriptions for each USE flag. If a "
"description is too long to fit on your screen, you can use the Left and Right "
"arrow keys to scroll the descriptions. Alternatively you can change the "
"description to show a reduced variant using the F10 key, or change the "
"display to wrap long lines into multiple lines using the F11 key.",
"",
"Use the Up and Down arrow keys, the Page Up and Page Down keys, the Home and "
"End keys, or start typing the name of a flag to select it.",
"Use the space bar to toggle the setting.",
"",
"You can apply various filters on the flags to display. The text of the bottom "
"line buttons show, which filter the button (or key press) will switch to.",
"",
" F5 : Toggle display of local / global / all flag descriptions.",
"",
" F6 : Toggle display of flags supported by at least one installed "
"package / supported by no installed package / all flags.",
"",
" F7 : Toggle display of masked and forced flags / flags that are "
"neither masked nor forced / all flags."
"",
"The default is to display all flags that are neither masked nor forced.",
"",
"You can change the way the descriptions are displayed. The text of the "
"bottom line buttons show, which way the button (or key press) the display "
"will change to.",
"",
" F9 : Toggle the order of the affected package list and the description.",
"",
" F10: Toggle whether to display the full description or a stripped version.",
"",
" F11: Enable / disable wrapping of long lines.",
"",
"The stripped version has various wordings like \"Enables support for\" or "
"\"Build and install the\" at the beginning of the description removed.",
"Although somewhat crippled, the descriptions key information then needs "
"less space and allows, with switched order of the package list and the "
"description, to determine a flags meaning without scrolling the text in most "
"cases; even on low resolution displays.",
"",
"The default is to display the full description preceded by the list of "
"affected packages.",
"",
"Below the list of descriptions an indicator line is displayed that shows the "
"current setting of all filters and settings.",
"The order and layout is:",
"[Scope|State|Mask|Order|Description|Wrapping] with",
"Scope:",
"  glob : Global USE flags are shown.",
"  loca : Local USE flags are shown.",
"  all  : All USE flags are shown.",
"State:",
"  inst : USE flags affecting installed packages are shown.",
"  noti : USE flags affecting not installed packages are shown.",
"  all  : All USE flags are shown",
"Mask:",
"  mask : Masked and forced USE flags are shown",
"  norm : USE flags that are neither masked nor forced are shown.",
"  all  : All USE flags are shown.",
"Order:",
"  left : The list of affected packages is shown left of the description.",
"  righ : The list of affected packages is shown right of the description.",
"Description:",
"  orig : The original full description is shown.",
"  stri : The stripped version of the description is shown.",
"Wrapping:",
"  long : The original one-line layout with horizontal scrolling.",
"  wrap : Wrapped lines that do not need horizontal scrolling.",
"",
"If ncurses is installed with the \"gpm\" use flag enabled, you can use your "
"mouse to navigate and to toggle the settings, too.",
"",
"After changing flags, press the Return or Enter key to save your USE flag "
"setup, or press Escape to revert your changes.",
"",
"Note: Depending on your system, you may need to wait a second before ufed "
"detects the Escape key or mouse clicks; in some cases, you can use the "
"ncurses environment variable ESCDELAY to change this. See the ncurses(3X) "
"manpage for more info.",
"",
"--- Display layout ---",
"",
"ufed attempts to show you where a particular use setting came from, and what "
"its scope and state is.",
"",
"The display consists of the following information:",
"",
" (s) flag  M|DPC|Si| (packages) description",
"",
"(s)  : Your selection",
"either [+] to enable, [-] to disable, or empty to keep "
"the default value. If a flag is enabled or disabled by default, it will be "
"shown as either (+) or (-).",
"",
"flag : The name of the flag.",
"If the flag is globally masked, it will be shown "
"as (-flag). If the flag is globally forced, it will be shown as (flag).",
"",
"D    : [D]efault settings",
"These are read from",
" /usr/portage/profiles/.../make.defaults",
"and the ebuild(5) IUSE defaults of installed packages. The settings in "
"make.defaults, however, take precedence over the ebuild IUSE settings.",
"Masked flags are shown here as 'm', forced flags as 'f'.",
"",
"P    : [P]rofile package settings.",
"These are read from",
" /usr/portage/profiles/.../package.use.",
"These package specific settings take precedence over the [D]efault settings.",
"",
"C    : [C]onfiguration settings",
"These are read from",
" /etc/make.conf",
" /etc/portage/make.conf and",
" /etc/portage/package.use.",
"These take precedence over the [D]efault and [P]rofile settings, with "
" package.use overriding settings from make.conf.",
"",
"S    : [S]cope of the description",
"Local flag descriptions have an 'L' for \"local\" here.",
"",
"i    : [i]nstalled",
"Indicates with an 'i' if either the listed packages are installed on your ",
"system, or if at least one package that supports this flag is installed. ",
"The latter applies to the global description of the flag.",
"",
"(packages): List of packages that support this flag.",
"",
"description : The description of the flag from use.desc or use.local.desc.",
"",
"If the character in any of the D, P or C column is a + then that USE flag was "
"set in that file(s), if it is a space then the flag was not mentioned in that "
"file(s) and if it is a - then that flag was unset in that file(s).",
"",
"Flags marked as [+] or [-] will be saved in your make.conf when you leave "
"the program by hitting the 'Enter' key",
"",
"You can change the order of the (packages) and the description with the F9 "
"key.",
"",
"--- REPORTING BUGS ---",
"",
"Please report bugs via http://bugs.gentoo.org/",
"",
"--- Credits ---",
"",
"ufed was originally written by Maik Schreiber <blizzy@blizzy.de>.",
"ufed was previously maintained by",
" Robin Johnson <robbat2@gentoo.org>,",
" Fred Van Andel <fava@gentoo.org>,",
" Arun Bhanu <codebear@gentoo.org> and",
" Harald van Dijk <truedfx@gentoo.org>.",
"ufed is currently maintained by",
" Sven Eden <yamakuzure@gmx.net>.",
"",
"--- Thanks ---",
" Paul Varner - for proxy maintaining and support.",
" Roman Zilka - for ideas, testing and a lot of patience.",
"",
"--------------",
"",
"Copyright 1999-2013 Gentoo Foundation",
"Distributed under the terms of the GNU General Public License v2"
};
	sFlag* line = NULL;
	size_t lineCount = sizeof(help) / sizeof(*help);
	size_t currLine  = 0;
	size_t n = 0;
	int    y = 0;
	const char* word = help[currLine];

	helpheight = wHeight(List);
	helpwidth  = wWidth(List);
	char buf[helpwidth + 1];
	memset(buf, 0, (helpwidth + 1) * sizeof(char));

	atexit(&free_lines);
	while( currLine < lineCount ) {
		line = addFlag(&lines, "help", y++, 1, "  ");

		// Find the last space character in the string
		// if it is too long to display.
		n = strlen(word);
		if(n > helpwidth - 1) {
			for(n = helpwidth-1; (n > 0) && (word[n] != ' '); --n) ;
			if(n==0)
				n = helpwidth;
		}

		// copy the text if there is any
		if (n) {
			memcpy(buf, word, n);
			buf[n++] = '\0';
			addFlagDesc(line, NULL, buf, NULL, "+      ");
		} else
			addFlagDesc(line, NULL, " ", NULL, "+      ");

		// Advance behind current spaces
		while (word[n] == ' ')
			n++;

		// See whether there is text left...
		if (strlen(word) > n)
			word += n;
		else if (++currLine < lineCount)
			// ...or advance one line
			word = help[currLine];
	}
}

static void free_lines(void)
{
	sFlag* line = lines->prev;

	// Clear all lines
	while (lines) {
		if (line)
			destroyFlag(&lines, &line);
		else
			destroyFlag(&lines, &lines);
		line = lines ? lines->prev ? lines->prev : lines : NULL;
	}
}


static int drawline(sFlag* line, bool highlight)
{
	char buf[wWidth(List)+1];

	sprintf(buf, "%-*.*s", wWidth(List), wWidth(List), line->desc[0].desc);

	if ('-' == buf[0]) {
		if (highlight)
			wattrset(win(List), COLOR_PAIR(5) | A_REVERSE);
		else
			wattrset(win(List), COLOR_PAIR(5) | A_BOLD);
	} else {
		if (highlight)
			wattrset(win(List), COLOR_PAIR(6) | A_BOLD);
		else
			wattrset(win(List), COLOR_PAIR(3));
	}

	mvwaddstr(win(List), line->currline, 0, buf);
	if(highlight)
		wmove(win(List), line->currline, 0);
	wnoutrefresh(win(List));
	return 1;
}

static int callback(sFlag** curr, int key)
{
	switch(key) {
		case 'Q': case 'q':
		case '\033':
			return 0;
#ifdef KEY_RESIZE
		case KEY_RESIZE:
			free_lines();
			init_lines();
			*curr = lines;
			return -2;
#endif
		default:
			return -1;
	}
}

void help(void)
{
	sKey keys[] = {
		MAKE_KEY('\033', "Esc", "Back", "", "", NULL, 0),
		MAKE_KEY('\0',   "",    "",     "", "", NULL, 0)
	};

	if ( ((int)helpheight != wHeight(List))
	  || ((int)helpwidth  != wWidth(List)) ) {
		if(lines!=NULL)
			free_lines();
		init_lines();
	}

	int oldVis = curs_set(0);
	maineventloop("", &callback, &drawline, lines, keys, false);
	curs_set(oldVis);
}
