#include <string.h>
#include <stdlib.h>

#include <proto/launch.h>

#include <kogata/region_alloc.h>
#include <kogata/debug.h>

#include <kogata/gip.h>
#include <kogata/draw.h>
#include <kogata/keyboard.h>

#define NCOLORS 16

const int vga_colors[NCOLORS] = {
	0x000000,
 	0x0000AA,
	0x00AA00,
	0x00AAAA,
	0xAA0000,
	0xAA00AA,
	0xAA5500,
	0xAAAAAA,
	0x555555,
	0x5555FF,
	0x55FF55,
	0x55FFFF,
	0xFF5555,
	0xFF55FF,
	0xFFFF55,
	0xFFFFFF,
};

typedef char tchar_t;

typedef struct {
	fb_info_t mode;
	fd_t fd;
	fb_t *fb;

	uint32_t sv_features, cl_features;
	fb_region_t damage;

	font_t *font;
	int cw, ch;	// size of a character

	color_t colors[NCOLORS];
	color_t fg, bg, csr_bg;

	char esc_seq[10];		// current escape sequence
	int esc_seq_len;		// current escape sequence length

	keyboard_t *kb;

	int w, h;
	tchar_t* scr_chars;
	int csrl, csrc;
	bool csr_visible;

	gip_handler_t *handler;
	mainloop_fd_t app;
	char rd_c_buf;
	char wr_c_buf;
} term_t;

void gip_buffer_info(gip_handler_t *s, gip_msg_header *p, gip_buffer_info_msg *m);
void gip_key_down(gip_handler_t *s, gip_msg_header *p);
void gip_key_up(gip_handler_t *s, gip_msg_header *p);
void gip_unknown_msg(gip_handler_t *s, gip_msg_header *p);
void gip_fd_error(gip_handler_t *s);

void gip_async_initiate(gip_handler_t *s, gip_msg_header *p, void* msgdata, void* hdata);

void term_on_rd_c(mainloop_fd_t *fd);
void term_app_on_error(mainloop_fd_t *fd);

void idle_cb(void* data);


gip_handler_callbacks_t term_gip_cb = {
	.reset = 0,
	.initiate = 0,
	.ok = 0,
	.failure = 0,
	.enable_features = 0,
	.disable_features = 0,
	.query_mode = 0,
	.set_mode = 0,
	.buffer_info = gip_buffer_info,
	.mode_info = 0,
	.buffer_damage = 0,
	.key_down = gip_key_down,
	.key_up = gip_key_up,
	.unknown_msg = gip_unknown_msg,
	.fd_error = gip_fd_error,
};


int main(int argc, char **argv) {
	dbg_print("[terminal] Starting up.\n");

	term_t term;
	memset(&term, 0, sizeof(term));

	term.kb = init_keyboard();
	ASSERT(term.kb != 0);

	term.font = g_load_ascii_bitmap_font("sys:/fonts/pcvga.bf");
	ASSERT(term.font != 0);
	term.cw = g_text_width(term.font, "#", 8);
	term.ch = g_text_height(term.font, "#", 8);

	term.damage.x = term.damage.y = term.damage.h = term.damage.w = -1;

	gip_handler_t *h = new_gip_handler(&term_gip_cb, &term);
	ASSERT(h != 0);
	term.handler = h;

	h->mainloop_item.fd = STD_FD_GIP;
	mainloop_add_fd(&h->mainloop_item);

	// setup communication with app
	term.app.fd = STD_FD_TTYSRV;
	term.app.on_error = term_app_on_error;
	term.app.data = &term;
	mainloop_expect(&term.app, &term.rd_c_buf, 1, term_on_rd_c);

	gip_msg_header reset_msg = { .code = GIPC_RESET, .arg = 0 };
	gip_cmd(h, &reset_msg, 0, gip_async_initiate, 0);

	mainloop_when_idle(idle_cb, &term);

	mainloop_run();

	return 0;
}

// Terminal features

void term_damage_at(term_t *t, int x, int y, int w, int h) {
	if (t->damage.x == -1) {
		t->damage.x = x;
		t->damage.y = y;
		t->damage.w = w;
		t->damage.h = h;
	} else {
		int px1 = t->damage.x + t->damage.w;
		int py1 = t->damage.y + t->damage.h;
		int nx1 = (px1 > x+w ? px1 : x+w);
		int ny1 = (py1 > y+h ? py1 : y+h);
		t->damage.x = (t->damage.x < x ? t->damage.x : x);
		t->damage.y = (t->damage.y < y ? t->damage.y : y);
		t->damage.w = nx1 - t->damage.x;
		t->damage.h = ny1 - t->damage.y;
	}
}

void term_draw_c(term_t *t, int l, int c) {
	color_t bg = t->bg;
	if (l == t->csrl && c == t->csrc) bg = t->csr_bg;

	char ss[2];
	ss[0] = t->scr_chars[l * t->w + c];
	ss[1] = 0;

	if (t->fb) {
		g_fillrect(t->fb, c * t->cw, l * t->ch, t->cw, t->ch, bg);
		g_write(t->fb, c * t->cw, l * t->ch, ss, t->font, 16, t->fg);
		term_damage_at(t, c * t->cw, l * t->ch, t->cw, t->ch);
	}
}

void term_move_cursor(term_t *t, int l, int c) {
	int l0 = t->csrl, c0 = t->csrc;
	t->csrl = l;
	t->csrc = c;
	term_draw_c(t, l0, c0);
	term_draw_c(t, l, c);
}

void term_put_at(term_t *t, int l, int c, tchar_t ch) {
	if (t->scr_chars[l * t->w + c] == ch) return;

	t->scr_chars[l * t->w + c] = ch;
	term_draw_c(t, l, c);
}

void term_clear_screen(term_t *t) {
	t->csr_visible = true;

	for (int i = 0; i < t->w * t->h; i++) t->scr_chars[i] = ' ';

	if (t->fb) {
		g_fillrect(t->fb, 0, 0, t->mode.width, t->mode.height, t->bg);
		term_damage_at(t, 0, 0, t->mode.width, t->mode.height);
	}

	term_move_cursor(t, 0, 0);
}

void term_scroll1(term_t *t) {
	for (int i = 0; i < t->w * (t->h - 1); i++)
		t->scr_chars[i] = t->scr_chars[i + t->w];
	for (int i = 0; i < t->w; i++) {
		t->scr_chars[i + (t->h - 1) * t->w] = ' ';
	}
	t->csrl--;

	if (t->fb) {
		g_scroll_up(t->fb, t->ch);
		g_fillrect(t->fb, 0, t->ch * (t->h - 1), t->cw * t->w, t->ch, t->bg);
		term_damage_at(t, 0, 0, t->mode.width, t->mode.height);
	}
}

void term_putc(term_t *t, int c) {
	if (t->esc_seq_len > 0 || c == '\e') {
		t->esc_seq[t->esc_seq_len++] = c;
	
		// parse escape sequence
		if (t->esc_seq_len >= 2) {
			if (t->esc_seq[1] == '[') {
				int n = 0, m = -1;
				int i = 2;
				for (; i < t->esc_seq_len && t->esc_seq[i] >= '0' && t->esc_seq[i] <= '9'; i++) {
					n = (n * 10) + (t->esc_seq[i] - '0');
				}
				if (i == t->esc_seq_len) return;	// incomplete sequence
				if (t->esc_seq[i] == ';') {
					i++;
					m = 0;
					for (; i < t->esc_seq_len && t->esc_seq[i] >= '0' && t->esc_seq[i] <= '9'; i++) {
						m = (m * 10) + (t->esc_seq[i] - 0);
					}
					if (i == t->esc_seq_len) return;	// incomplete sequence
				}
				// TODO implement escape sequence handling
				if (t->esc_seq[i] == 'A') {
					// move cursor up
				} else if (t->esc_seq[i] == 'B') {
					// move cursor down
				} else if (t->esc_seq[i] == 'C') {
					// move cursor forward
				} else if (t->esc_seq[i] == 'D') {
					// move cursor back
				} else if (t->esc_seq[i] == 'E') {
					// move cursor n lines down to begin of line
				} else if (t->esc_seq[i] == 'F') {
					// move cursor n lines up to begin of line
				} else if (t->esc_seq[i] == 'H' || t->esc_seq[i] == 'f') {
					// move cursor to position (n, m)
				} else if (t->esc_seq[i] == 'J' || t->esc_seq[i] == 'K') {
					// erase data/line
				} else if (t->esc_seq[i] == 'S') {
					// scroll up n lines
				} else if (t->esc_seq[i] == 'T') {
					// scroll down n lines
				} else if (t->esc_seq[i] == 'm') {
					// select graphic rendition (ie color)
					if (n == 0) {
						t->fg = t->colors[7];
						t->bg = t->colors[0];
					} else if (n >= 30 && n <= 37) {
						t->fg = t->colors[n - 30];
					} else if (n == 39) {
						t->fg = t->colors[7];
					} else if (n >= 40 && n <= 47) {
						t->bg = t->colors[n - 40];
					} else if (n == 49) {
						t->bg = t->colors[0];
					}
				} else if (t->esc_seq[i] == 'n') {
					// device status report
				} else if (t->esc_seq[i] == 's') {
					// save cursor position
				} else if (t->esc_seq[i] == 'p') {
					// restore cursor position
				}
			}
			t->esc_seq_len = 0;	// sequence finished
		}
	} else {
		int nl = t->csrl, nc = t->csrc;
		if (c == '\n') {
			nl++; nc = 0;
		} else if (c == '\r') {
			while (nc > 0) {
				nc--;
				term_put_at(t, nl, nc, ' ');
			}
			nc = 0;
		} else if (c == '\f') {
			term_clear_screen(t);
			return;
		} else if (c == '\b') {
			if (nc > 0) {
				nc--;
			}
			term_put_at(t, nl, nc, ' ');
		} else if (c == '\t') {
			while (nc % 8 != 0) {
				term_put_at(t, nl, nc, ' ');
				nc++;
			}
		} else if (c >= ' ' && c < 128) {
			term_put_at(t, nl, nc, c);
			nc++;
		}
		if (nc >= t->w) {
			nc = 0;
			nl++;
		}
		if (nl >= t->h) {
			term_scroll1(t);
			nl--;
		}
		term_move_cursor(t, nl, nc);
	}
}

void term_puts(term_t *t, char* s) {
	while ((*s) != 0) {
		term_putc(t, *s);
		s++;
	}
}

// GIP client connection

void gip_buffer_info(gip_handler_t *s, gip_msg_header *p, gip_buffer_info_msg *m) {
	dbg_printf("[terminal] Got buffer info msg\n");

	term_t *c = (term_t*)s->data;

	if (c->fb != 0) {
		g_decref_fb(c->fb);
		c->fb = 0;
	}
	if (c->fd != 0) {
		sc_close(c->fd);
		c->fd = 0;
	}

	c->fd = sc_use_token(&m->tok);
	if (c->fd != 0) {
		memcpy(&c->mode, &m->geom, sizeof(fb_info_t));

		dbg_printf("[terminal] Got buffer on FD %d, %dx%dx%d\n",
			c->fd, c->mode.width, c->mode.height, c->mode.bpp);

		if (c->scr_chars != 0) {
			free(c->scr_chars);
			c->scr_chars = 0;
		}
		c->w = c->mode.width / c->cw;
		c->h = c->mode.height / c->ch;
		c->scr_chars = (tchar_t*)malloc(c->w * c->h * sizeof(tchar_t));
		ASSERT(c->scr_chars != 0);

		c->fb = g_fb_from_file(c->fd, &m->geom);
		if (c->fb != 0) {
			for (int i = 0; i < NCOLORS; i++) {
				c->colors[i] = g_color_rgb(c->fb, (vga_colors[i] >> 16) & 0xFF,
						(vga_colors[i] >> 8) & 0xFF, vga_colors[i] & 0xFF);
			}
			c->bg = c->colors[0];
			c->fg = c->colors[7];
			c->csr_bg = c->colors[2];

			term_clear_screen(c);

			mainloop_rm_fd(&c->app);
			mainloop_add_fd(&c->app);
		} else {
			dbg_printf("[terminal] Could not open framebuffer file %d\n", c->fd);
		}

	}
}

void gip_key_down(gip_handler_t *s, gip_msg_header *p) {
	term_t *c = (term_t*)s->data;

	key_t k = keyboard_press(c->kb, p->arg);

	c->wr_c_buf = 0;
	if (k.flags & KBD_CHAR) {
		c->wr_c_buf = k.chr;
	} else {
		if (k.key == KBD_CODE_RETURN) c->wr_c_buf = '\n';
		if (k.key == KBD_CODE_TAB) c->wr_c_buf = '\t';
		if (k.key == KBD_CODE_BKSP) c->wr_c_buf = '\b';
	}
	if (c->wr_c_buf != 0) {
		term_putc(c, c->wr_c_buf);
		mainloop_nonblocking_write(&c->app, &c->wr_c_buf, 1, false);
	}
}

void gip_key_up(gip_handler_t *s, gip_msg_header *p) {
	term_t *c = (term_t*)s->data;

	keyboard_release(c->kb, p->arg);
}

void gip_unknown_msg(gip_handler_t *s, gip_msg_header *p) {
	// TODO
}

void gip_fd_error(gip_handler_t *s) {
	// TODO
}

void term_on_rd_c(mainloop_fd_t *fd) {
	term_t *t = (term_t*)fd->data;

	term_putc(t, t->rd_c_buf);
}

void idle_cb(void* data) {
	term_t *t = (term_t*)data;

	// we are done processing events ; flush damaged region
	if (t->damage.x != -1) {
		gip_msg_header damage_msg = { .code = GIPN_BUFFER_DAMAGE, .arg = 0 };
		gip_cmd(t->handler, &damage_msg, &t->damage, 0, 0);
		t->damage.x = t->damage.y = t->damage.w = t->damage.h = -1;
	}
}

void term_app_on_error(mainloop_fd_t *fd) {
	// TODO
}

void gip_async_initiate(gip_handler_t *s, gip_msg_header *p, void* msgdata, void* hdata) {
	term_t *c = (term_t*)s->data;
	c->sv_features = p->arg;

	dbg_printf("[temrinal] Got initiate reply to reset request (features 0x%p).\n", c->sv_features);
}

/* vim: set ts=4 sw=4 tw=0 noet :*/