// Copyright 2021, Paul Mosier
//
// This file is part of Scriptura, a ncurses-based Bible study
// software for the libsword backend.
//
// Scriptura is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, under version 2 of the License.
//
// Scriptura is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Scriptura.  If not, see <https://www.gnu.org/licenses/>.

// pane.cpp -- subwindow management

#include <stdlib.h>
#include <ncurses.h>
#include <menu.h>
#include <form.h>
#include <string.h>
#include <wchar.h>

#include "pane.h"

// constructor
pane::pane(int starty, int startx, int lines, int cols, const char* title,
					 modkey defmod) {

	buflocx = buflocy = 0;
	hasFocus = false;
	rawtext = NULL;

	// set up the window -- resize will give us some initializing
	setTitle(title);
	pad = NULL;
	resize(starty, startx, lines, cols);
	redraw(true);

	// forms/menus send in a null searchkey
	if (defmod.searchkey != NULL) {
		setModkey(defmod, title);
	}
}

// handle pane resizing
void pane::resize(int starty, int startx, int lines, int cols) {
	y = starty;
	x = startx;
	height = lines;
	width = cols;

	win = newwin(height, width, y, x);

	/* if pad is a curses subwindow (made by derwin) then we close it rather than
	 * resize it, so we only check for pads proper to manage text handling */
	if (is_pad(pad)) renderText();
}

/* trap new text to render, and then pass along to our render function */
void pane::loadText(const char* stext) {
	free(rawtext);
	rawtext = (char*) malloc(sizeof(char*) * strlen(stext) + 1);
	if (! rawtext) wrapup(1, "Error allocating memory in loadText.\n");
	memset(rawtext, '\0', strlen(stext) + 1);
	strncpy(rawtext, stext, strlen(stext));
	free((void*) stext); // alloc'd in scabbard::getSpan
	renderText();
}

/* create a new pad with the boundaries tightly fitting around a block of
 * formatted text */
void pane::renderText() {
	// pad is an ncurses pad - set what dimensions we know right now
	pady = y + 1;
	padx = x + 1;
	padrows = height - 2;
	padcols = width - 2;
	bufsizex = padcols;
	buflocx = 0;
	buflocy = 0;

	// here we define some counters & flags
	int length = strlen(rawtext);
 	int numlines = 0;         // number of newlines
	int linelength = 0;       // how long the current line is
	int lastspaceidx = 0;     // where was the last space relative to the string
	int printable = 0;        // index of printed characters
	int lastprintspace = 0;   // where was the last space relative to printed chars
	int inmarkup = 0;         // are we in a non-printed markup block
	int makered = 0;          // redletter flag
	int makeital = 0;         // italic flag

	// pull config variables
	int rawonly = parseConf(config["markup"]["rawtext"]);
	int redletter = parseConf(config["markup"]["redletters"]);
	int strongs = parseConf(config["markup"]["strongs"]);
	int nontextual = parseConf(config["markup"]["nontextual"]);
	// int footnotes = 0;		not implemented yet

	// copy our unformatted text to local scope for window formatting
	char* text = (char*) malloc(sizeof(char*) * length + 1);
	if (! text) wrapup(1, "Error allocating memory in renderText.\n");
	memset(text, '\0', strlen(rawtext) + 1);
	strncpy(text, rawtext, length);

	// kept for debugging
	//fwprintf(stderr, L"(O): %ls\n\n", text);

	/* here's the workhorse - loop through the text twice: first to alter the
	 * text for word wrapping and to count the number of lines we have so we
	 * can define the pad size; second to print the text with the correct
	 * markup */
	for (int p = 0; p < 2; p++) {

		// loop through the text
		int i = 0;
		while (i < length) {

			/* check if we're in markup - it's not printed and it doesn't
			 * affect our line lengths, so spin through it */
			if (inmarkup) {
				if (text[i] == '>') inmarkup = 0;
				i++;
				continue;
			}

			// check if we're entering markup - if so, figure out what
			if ((text[i] == '<') && (! rawonly)) {
				inmarkup = 1;

				if ((! strmatch(&text[i], "</q>", 1)) && (p == 1)) {
					// end of redletter bracket
					makered = 0;

				} else if ((! strmatch(&text[i], "</transChange>", 1))
									 && (p == 1)) {
					// end of interpretive text bracket
					makeital = 0;

				} else if ((! strmatch(&text[i], "<p>", 1)) && (p == 0)) {
					// paragraph break - replace </p> with </>'\n'
					int endindex = strmatch(&text[i], "</p>", 0);
					if (endindex != -1)
						memcpy(&text[i + endindex + 2], ">\n", 2);

				} else if ((! strmatch(&text[i], "<w savlm=", 1))
									 && (p == 0) && (strongs == 1)) {
					/* Strong's number - the format is below, but note
					 * there may be 1+ strong:[G|H]NNNN(N)'s to find,
					 * and other junk to ignore both within the same
					 * parameter, and before the word
					 * <w savlm="strong:[G|H]NNNN(N)">word</w> */

					// 1. get boundary of open tag
					int endbracket = strmatch(&text[i], ">", 0);

					// 2. get Strong's parameters
					char* num = (char*) malloc(sizeof(char*) * 100);
					if (! num) wrapup(1,
										"Error declaring memory in renderText.\n");
					int numidx = 0;

					int strnum = strmatch(&text[i], "strong:", 0) + 7;
					while ((strnum < endbracket) && (strnum != -1)) {
						int nextspace = strmatch(&text[i+strnum], " ", 0);
						int space1 = strmatch(&text[i+strnum], "\"", 0);
						int len = ((nextspace == -1) || (space1 < nextspace)
														 ? space1
														 : nextspace);

						if (numidx != 0) memcpy(&num[numidx++], " ", 1);
						memcpy(&num[numidx], &text[i+strnum], len);
						numidx += len;

						int nextnum =
							strmatch(&text[i+strnum], "strong:", 0);
						strnum = (nextnum != -1
											? strnum + nextnum + 7
											: -1);
					}

					/* 3. determine if tag is empty closed-element,
					 * if so, rewrite in place by making wordlen
					 * below zero, otherwise get word boundaries */
					int wordstart = endbracket + 1;
					int endtag =
						(endbracket > strmatch(&text[i], "/", 0)
						 ? endbracket + 1
						 : strmatch(&text[i], "</w>", 0));

					// 4. determine word boundaries & rewrite
					int wordlen = endtag - wordstart;
					char* word = (char*) malloc(sizeof(char*)
														* (wordlen == 0 ? 1 : wordlen));

					if (! word) wrapup(1,
								 "Error rewriting markup in renderText.\n");
					memcpy(word, &text[i+wordstart], wordlen);

					// rewrite
					int start = i + endtag - wordlen - numidx - 4;
					memcpy(&text[start], "\"", 1);
					memcpy(&text[start + 1], ">", 1);
					memcpy(&text[start + 2], word, wordlen);
					memcpy(&text[start + 2 + wordlen], "[", 1);
					memcpy(&text[start + 3 + wordlen], num, numidx);
					memcpy(&text[start + 3 + wordlen + numidx], "]", 1);

					// clean up so we can do this again
					free(num);
					free(word);

					// kept for debugging
					//fwprintf(stderr, L"(I): %ls\n", text);

				} else if ((! strmatch(&text[i], "<q marker", 1))
									 && (p == 1) && (redletter == 1)) {
					// start of redletter bracket
					makered = 1;

				} else if ((! strmatch(&text[i], "<transChange type=\"added\"", 1))
									 && (p == 1) && (nontextual == 1)) {
					// start of interpretive text bracket
					makeital = 1;
				}

				// don't print the angle bracket
				continue;
			} // markup check

			/* determine how large this multibyte character is -- we will need it to
			 * determine our advance amount in the loop */
			int offset = 0;
			size_t charlen = mbrlen(&text[i], 5, NULL);
			while (((int) mbrlen(&text[i+offset], 5, NULL) == -1) &&
						 (i + offset < length)) {
				/* mbrlen() says the next char is not a valid multibyte char, so find
				 * the length by figuring out where the succeeding character is */
				offset++;
			}

			if (p == 0) {
				// handle word wrapping
				if (text[i] == ' ') {
					/* if under the buffer width, note index & continue
					 * if over, set the preceeding space to a newline */
					if (linelength >= bufsizex) {
						text[lastspaceidx] = '\n';
						numlines++;
						// start counting from the beginning of the last word
						linelength = printable - lastprintspace;
					} else {
						lastspaceidx = i;
						lastprintspace = printable;
					}
				}
				// reset for newlines
				if (text[i] == '\n') {
					/* check to see if we're still over the length but hit a
					 * newline before a space */
					if (linelength >= bufsizex) {
						text[lastspaceidx] = '\n';
						numlines++;
					}
					numlines++;
					linelength = 0;
					lastspaceidx = i;
					lastprintspace = printable;
				}

				linelength++;

				// various word wrapping debugging statements
				//fprintf(stderr, "[ %c ] : 0x%X\n", text[i], text[i]);
				//fprintf(stderr, "Char: %c  I: %d  Numlines: %d  "
				//			"Linelength: %d  Lastspaceidx: %d\n",
				//	text[i], printable, numlines, linelength, lastspaceidx);

			} else {
				// printing -- pull out the single character we care about
				wattrset(pad, COLOR_PAIR(makered)
								 | (makeital ? A_ITALIC : 0));

				if (((int) charlen == -1) && (offset == 1)) {
					/* This is an extended ascii character (probably Latin-1) and not
					 * UTF-8.  In setting up ncurses for UTF-8 we set a locale and seem to
					 * make these characters unprintable.  To avoid massive rendering
					 * errors we have to substitute them with something else. */
					waddstr(pad, "?");

				} else waddnstr(pad, &text[i], charlen);
			}

			printable++;
			i += ((int) charlen == -1 ? offset : (int) charlen);
		} // text loop

		// text rewriting debugging
		//fwprintf(stderr, L"\n(F): %ls\n\n\n", text);

		if (p == 0) {
			// now that we have the number of newlines, create the pad to fit
			bufsizey = numlines;
			pad = newpad(bufsizey + 1, bufsizex);
			if (! pad) wrapup(1, "Error constructing pad in renderText.\n");
			scrollok(pad, true);
			wmove(pad, 0, 0);
		}

	} // workhorse
	free(text);
	redraw();
}

void pane::setTitle(const char* newtitle) {
	// NOTE -- hardcoded length for title string
	if (strlen(newtitle) < 40) {
		strcpy(titlebar, newtitle);
	} else {
		strncpy(titlebar, newtitle, 36);
		strcpy(titlebar+36, "...");
	}
}

void pane::retitle() {
	(hasFocus ? wattrset(win, A_STANDOUT) : standend());
	mvwprintw(win, 0, 1, "%s%s%s", "  ", titlebar, "   ");
	wstandend(win);
}

void pane::redraw(bool borders) {
	if (borders) {
		box(win, 0, 0);
		retitle();
	}
	wrefresh(win);
	if (is_pad(pad)) {
		prefresh(pad, buflocy, buflocx, pady, padx, pady + height - 3,
		  padx + width - 1);
	} else {
		wrefresh(pad);
	}
}

void pane::nextPage() {
	buflocy = (bufsizey - buflocy > 2 * padrows
						 ? buflocy + padrows - 1
						 : bufsizey - padrows);
	redraw();
}

void pane::scrollDown() {
	if (bufsizey - buflocy > padrows) buflocy++;
	redraw();
}

void pane::scrollUp() {
	if (buflocy > 0) buflocy--;
	redraw();
}

void pane::prevPage() {
	buflocy = (buflocy > padrows ? buflocy - padrows : 0);
	redraw();
}

void pane::toggleFocus() {
	hasFocus = !hasFocus;
	retitle();
	redraw();
}

int pane::loadMenu(starray opts) {
	// instruction text
	const char* inst = "(Up/Down - scroll   PgUp/PgDn - page up/down"
		"   Enter - select   ESC - cancel)";
	pady = printInstructions(2, inst);

	// construct list of items
	ITEM **items = (ITEM**) malloc(sizeof(ITEM*) * (opts.length+1));
	if (! items) wrapup(1, "Error allocating memory in loadMenu.\n");
	for (int i = 0; i < opts.length; i++)
		items[i] = new_item((opts.strings)[i], (opts.strings)[i]);
	items[opts.length] = (ITEM*) NULL;

	// pad is a ncurses subwindow - set coords relative to win's X & Y
	pady++;
	padx = 4;
	padrows = height - 6;
	padcols = width - 6;

	pad = derwin(win, padrows, padcols, pady, padx);
	keypad(pad, true);

	// create the menu & header
	MENU *menu = new_menu((ITEM**) items);
	menu_opts_off(menu, O_SHOWDESC);
	set_menu_win(menu, win);
	set_menu_sub(menu, pad);
	set_menu_mark(menu, "-> ");
	set_menu_format(menu, padrows, 1);		// set scrolling
	post_menu(menu);
	redraw();

	// hit escape to exit without a choice
	int ch;
	while (((ch = getch()) != 27) && (ch != KEY_RESIZE)) {
		switch (ch) {

			case KEY_PPAGE:
				menu_driver(menu, REQ_SCR_UPAGE);
				break;

			case KEY_UP:
				menu_driver(menu, REQ_UP_ITEM);
				break;

			case KEY_DOWN:
				menu_driver(menu, REQ_DOWN_ITEM);
				break;

			case KEY_NPAGE:
				menu_driver(menu, REQ_SCR_DPAGE);
				break;

			case '\n':	// enter
				int retval = item_index(current_item(menu));
				menuClean(menu, items, opts.length);
				return retval;
				break;
		}
		redraw();
	}

	// user backed out, return nothing
	menuClean(menu, items, opts.length);
	return (ch == KEY_RESIZE ? -2 : -1);
}

int pane::printInstructions(int y, const char* inst) {
	// NOTE -- starting indentation is hardcoded at two characters in
	long unsigned int strctr = 0;
	long unsigned int line = width - 3;
	while (strlen(&inst[strctr]) > line) {
		// set write length to be up to the last space, for word wrapping
		while ((inst[line] != ' ') && (line > 0)) line--;
		if (line == 0) line = width - 3;

		mvwaddnstr(win, y++, 2, &inst[strctr], line);

		strctr += line;
		line = width - 3;
	}

	if (strlen(inst) != strctr)
		mvwaddnstr(win, y++, 2, &inst[strctr], -1);

	return y;
}

starray pane::loadForm(starray inputs, const char* secondinst) {
	/* instruction text -- add text using mvwaddnstr because we don't know how
	 * large the window is */
	const char* firstinst = "(Up/Down - scroll   Enter - select   ESC - cancel)";
	pady = printInstructions(2, firstinst);
	pady = printInstructions(pady, secondinst);

	// pad is a ncurses subwindow - set coords relative to win's X & Y
	padx = 40;
	padrows = height - 5;
	padcols = width - 45;

	pad = derwin(win, padrows, padcols, pady, padx);
	keypad(win, true);
	curs_set(1);

	// find out how many valid fields we have
	int validfields = 1;
	for (int i = 0; i < inputs.length; i++) {
		// find out how many extra lines we'll need to put in the form
		if (strcmp((inputs.strings)[i], "SPACE") != 0) validfields++;
	}
	FIELD *fields[validfields];

	// construct list of fields
	int yoffset = 1;
	int fieldnum = 0;
	for (int i = 0; i < inputs.length; i++) {
		if (strcmp((inputs.strings)[i], "SPACE") == 0) {
			// put in the space
			yoffset++;
			continue;
		}
		fields[fieldnum] = new_field(1, 30, yoffset, 1, 0, 0);
		mvwprintw(win, yoffset + pady, 2, "%s", (inputs.strings)[i]);
		yoffset++;
		set_field_back(fields[fieldnum], A_UNDERLINE);
		field_opts_off(fields[fieldnum], O_AUTOSKIP);
		fieldnum++;
	}
	fields[validfields-1] = NULL;

	// create the form
	FORM *form = new_form(fields);
	set_form_win(form, win);
	set_form_sub(form, pad);
	post_form(form);

	// show everything
	redraw();

	// hit escape or resize terminal to exit without a choice
	int ch;
	starray retval;
	retval = stinit(retval);
	while (((ch = wgetch(win)) != 27) && (ch != KEY_RESIZE)) {
		switch (ch) {

			case KEY_UP:
				form_driver(form, REQ_PREV_FIELD);
				form_driver(form, REQ_END_LINE);
				break;

			case KEY_DOWN:
				form_driver(form, REQ_NEXT_FIELD);
				form_driver(form, REQ_END_LINE);
				break;

			case KEY_BACKSPACE:
			case 127:	// these are all backspace - it's terminfo dependent
			case '\b':
				form_driver(form, REQ_DEL_PREV);
				break;

			case '\n':	// enter key - exit out here
				// force validation to ensure last field is written to buffer
				form_driver(form, REQ_VALIDATION);

				// get inputs
				for (int i = 0; i < validfields-1; i++) {
					char* inp = strdup(field_buffer(fields[i], 0));
					trim(inp);
					retval = stappend(retval, inp);
				}

				// clean up
				formClean(form, fields, validfields);
				return retval;
				break;

			default:
				// add character to input
				form_driver(form, ch);
				break;
		}
	}

	// user backed out, return nothing
	formClean(form, fields, validfields);
	if (ch == KEY_RESIZE) retval.length = -1;
	return retval;
}

void pane::menuClean(MENU* menu, ITEM** items, int numitems) {
	unpost_menu(menu);
	free_menu(menu);
	for (int i = 0; i < numitems + 1; i++) free_item(items[i]);
	free(items);
}

void pane::formClean(FORM* form, FIELD** fields, int numfields) {
	unpost_form(form);
	free_form(form);
	curs_set(0);
	for (int i = 0; i < numfields; i++) free_field(fields[i]);
}

void pane::setModule(const char* newtitle, const char* newmod,
										 int keytype) {
	mod.modname = newmod;
	mod.keytype = keytype;
	setTitle(newtitle);
	// update titlebar
	redraw(true);
}

void pane::setKey(const char* newkey) {
	mod.searchkey = newkey;
	setSearch(DEFSEARCH, "Gen 1:1 - Rev 22:21");
}

void pane::setSearch(int type, const char* scope) {
	mod.searchtype = type;
	mod.scope = scope;
}

void pane::setModkey(modkey newmod, const char* newtitle) {
	setModule(newtitle, newmod.modname, newmod.keytype);
	setKey(newmod.searchkey);
	setSearch(newmod.searchtype, newmod.scope);
}