#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <assert.h>
#include <SharedGraphics/Font.h>
#include <SharedGraphics/GraphicsBitmap.h>
#include <SharedGraphics/Painter.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <LibC/gui.h>
#include "Terminal.h"

static void make_shell(int ptm_fd)
{
    pid_t pid = fork();
    if (pid == 0) {
        const char* tty_name = ptsname(ptm_fd);
        if (!tty_name) {
            perror("ptsname");
            exit(1);
        }
        int rc = 0;
        close(ptm_fd);
        int pts_fd = open(tty_name, O_RDWR);
        dbgprintf("*** In child (%d), opening slave pty %s, pts_fd=%d\n", getpid(), tty_name, pts_fd);
        rc = ioctl(0, TIOCNOTTY);
        if (rc < 0) {
            perror("ioctl(TIOCNOTTY)");
            exit(1);
        }
        close(0);
        close(1);
        close(2);
        dup2(pts_fd, 0);
        dup2(pts_fd, 1);
        dup2(pts_fd, 2);
        close(pts_fd);
        rc = ioctl(0, TIOCSCTTY);
        if (rc < 0) {
            perror("ioctl(TIOCSCTTY)");
            exit(1);
        }
        rc = execvp("/bin/sh", nullptr);
        if (rc < 0) {
            perror("execve");
            exit(1);
        }
        ASSERT_NOT_REACHED();
    } else {
        dbgprintf("*** In parent, child is %d\n", pid);
    }
}

static int max(int a, int b)
{
    return a > b ? a : b;
}

int main(int, char**)
{
    int ptm_fd = open("/dev/ptmx", O_RDWR);
    if (ptm_fd < 0) {
        perror("open(ptmx)");
        return 1;
    }

    make_shell(ptm_fd);

    int event_fd = open("/dev/gui_events", O_RDONLY);
    if (event_fd < 0) {
        perror("open");
        return 1;
    }

    Terminal terminal;
    terminal.create_window();
    terminal.paint();

    for (;;) {
        fd_set rfds;
        FD_ZERO(&rfds);
        FD_SET(ptm_fd, &rfds);
        FD_SET(event_fd, &rfds);
        int nfds = select(max(ptm_fd, event_fd) + 1, &rfds, nullptr, nullptr, nullptr);
        if (nfds < 0) {
            dbgprintf("Terminal(%u) select() failed :( errno=%d\n", getpid(), errno);
        }

        if (FD_ISSET(ptm_fd, &rfds)) {
            byte buffer[1024];
            ssize_t nread = read(ptm_fd, buffer, sizeof(buffer));
            if (nread < 0) {
                perror("read(ptm)");
                continue;
            }
            assert(nread != 0);
            for (ssize_t i = 0; i < nread; ++i)
                terminal.on_char(buffer[i]);
            terminal.paint();
        }

        if (FD_ISSET(event_fd, &rfds)) {
            GUI_Event event;
            ssize_t nread = read(event_fd, &event, sizeof(event));
            if (nread < 0) {
                perror("read(event)");
                return 1;
            }
            assert(nread != 0);
            assert(nread == sizeof(event));

            if (event.type == GUI_Event::Type::Paint) {
                terminal.paint();
            } else if (event.type == GUI_Event::Type::KeyDown) {
                char ch = event.key.character;
                if (event.key.ctrl) {
                    if (ch >= 'a' && ch <= 'z') {
                        ch = ch - 'a' + 1;
                    } else if (ch == '\\') {
                        ch = 0x1c;
                    }
                }
                write(ptm_fd, &ch, 1);
            } else if (event.type == GUI_Event::Type::WindowActivated) {
                terminal.set_in_active_window(true);
            } else if (event.type == GUI_Event::Type::WindowDeactivated) {
                terminal.set_in_active_window(false);
            }
        }
    }
    return 0;
}