#include <atari.h>
#include <conio.h>
#include <string.h>
#include "addrs.h"
#include "screen.h"
#include "edbox.h"
#include "keyclick.h"

/* TODO: tab completion */

int edbox_visible = 0;
static u16 edbox_pos; /* range 0 to EDBOX_SIZE - 1 */
static u16 edbox_len; /* idem */

void (*edbox_callback)(void);

static void hide_cursor(void) {
	edit_box[edbox_pos] &= 0x7f;
}

static void show_cursor(void) {
	edit_box[edbox_pos] |= 0x80;
}

void edbox_clear(void) {
	memset(edit_box, 0, EDBOX_SIZE);
	edbox_pos = edbox_len = 0;
	show_cursor(); // not needed? seems it is..
}

void edbox_show(void) {
	u16 addr;

	if(edbox_pos < 80)
		addr = (u16)edit_box;
	else
		addr = (u16)edit_box + edbox_pos - 79;

	scr_waitvcount(116);

	*dlist_status_lms = addr;
	*dlist_last_line = 0x02; /* ANTIC GR.0 */
	edbox_visible = 1;
	show_cursor();
}

void edbox_hide(void) {
	scr_end_scrollback(); /* exit Start+E mode */
	edbox_visible = 0;
	scr_refresh();
}

/* note: c will never be an EOL.
   idea: when the edbox is completely full (240 chars), go
   ahead and pretend the user pressed Return (call edbox_callback,
   etc). not sure if this is more or less annoying than just
   refusing to accept more input until Return is pressed. */
void edbox_putc(char c) {
	extern void __fastcall__ bell(void);

	if(!c)
		return; /* no inserting nulls */

	memmove(edit_box + edbox_pos + 1, edit_box + edbox_pos, EDBOX_SIZE - edbox_pos - 1);
	edit_box[edbox_pos] = c;
	if(edbox_pos < EDBOX_SIZE - 1) {
		edbox_pos++;
		edbox_len++;
	} else {
		bell();
	}
}

static void fake_keystroke(char c) {
	keyclick();
	OS.ch = 0xff;
	edbox_putc(c);
}

static void del_char(void) {
	if(!edbox_len) return;
	memmove(edit_box + edbox_pos, edit_box + edbox_pos + 1, EDBOX_SIZE - edbox_pos - 1);
	edbox_len--;
}

static void del_to_end(void) {
	while(edbox_len > edbox_pos)
		del_char();
}

static void backspace(void) {
	if(!edbox_pos) return;
	edbox_pos--;
	del_char();
}

static void word_left(char del) {
	if(!edbox_pos) return;
	if(!del) edbox_pos--;
	while(edbox_pos && edit_box[edbox_pos] == ' ') {
		if(del) del_char();
		edbox_pos--;
	}
	while(edbox_pos && edit_box[edbox_pos] != ' ') {
		if(del) del_char();
		edbox_pos--;
	}
	// XXX: what's this good for?
	if(del && !edbox_pos) edit_box[edbox_pos] = /* ' ' */ 0;
}

static void del_word(void) {
	word_left(1);
}

static void back_word(void) {
	word_left(0);
}

static void forward_word(void) {
	while(edbox_pos < edbox_len && edit_box[edbox_pos] == ' ')
		edbox_pos++;
	while(edbox_pos < edbox_len && edit_box[edbox_pos] != ' ')
		edbox_pos++;
}

static void del_to_start(void) {
	while(edbox_pos) backspace();
}

static void normal_keystroke(void) {
	char c;

	c = cgetc();

	switch(c) {
		case CH_EOL:
			// hide_cursor(); // already done by the caller
			edbox_hide();
			if(edbox_callback)
				(*edbox_callback)();
			edbox_clear();
			break;
		case CH_CLR:
			edbox_hide();
			/* fall thru */
		case CH_DELLINE:
			edbox_clear();
			break;
		case 0x15: /* ^U */
			del_to_start();
			break;
		case 0x0b: /* ^K */
			del_to_end();
			break;
		case CH_DEL:
			backspace();
			break;
		case 0x02: /* ^B */
			back_word();
			break;
		case 0x06: /* ^F */
			forward_word();
			break;
		case 0x17: /* ^W */
			del_word();
			break;
		case CH_CURS_LEFT:
			if(edbox_pos) edbox_pos--;
			break;
		case CH_CURS_RIGHT:
			if(edbox_pos < edbox_len) edbox_pos++;
			break;
		case CH_CURS_UP:
			if(edbox_pos > 39) edbox_pos -= 40;
			break;
		case CH_CURS_DOWN:
			if(edbox_pos < edbox_len - 40)
				edbox_pos += 40;
			else
				edbox_pos = edbox_len;
			break;
		case CH_DELCHR:
			del_char();
			break;
		case 0x01: /* ^A */
			edbox_pos = 0;
			break;
		case 0x05: /* ^E */
			edbox_pos = edbox_len;
			break;
		default:
			edbox_putc(c);
			break;
	}
}

void edbox_keystroke(void) {
	char c;

	while(OS.ch == 0xff)
		;

	/* filter out all ctrl-shift key combos except the ones
	   we actually support */
	if(OS.ch == 0xce) {
		/* ctrl-shift-up, same as ^B = back 1 word */
		OS.ch = 0x95;
	} else if(OS.ch == 0xcf) {
		/* ctrl-shift-down, same as ^F = forward 1 word */
		OS.ch = 0xb8;
	} else if(OS.ch > 0xbf) {
		OS.ch = 0xff;
		return;
	}

	edbox_show();

	c = 0;

	switch(OS.ch) {
		case 0xa0:       /* key: ctrl [ */
			c = 0x7b;     /* ascii: { */
			break;
		case 0xa2:       /* key: ctrl ] */
			c = 0x7d;     /* ascii: } */
			break;
		case 0x1c:       /* key: ESC */
			c = 0x60;     /* ascii: ` */
			break;
		case 0x5c:       /* key: shift ESC */
		case 0x9c:       /* key: ctrl ESC */
			c = 0x7e;     /* ascii: ~ */
			break;
		case 0x3c:       /* caps */
		case 0x7c:       /* shift-caps */
		case 0xbc:       /* ctrl-caps */
			OS.shflok ^= 0x40;
			keyclick();
			OS.ch = 0xff;
			return;
			break;
		case 0x27:       /* atari key */
		case 0x67:       /* ...w/shift */
		case 0xa7:       /* ...w/ctrl */
			c = 0x02;     /* ^B = IRC bold formatting char */
			break;
		case 0x9a:       /* ctrl-3 (crash if cgetc() reads it!) */
			OS.ch = 0xff; /* ignore it! */
			return;
			break;
		default:
			break;
	}

	hide_cursor();

	if(c) {
		fake_keystroke(c);
	} else {
		normal_keystroke();
	}

	if(edbox_visible) edbox_show();
	show_cursor();
}