import fcntl, os, select, pty, threading

from buffer import Buffer, ACT_NORM, ACT_NONE
from term import XTerm
from point import Point

# evil evil evil evil evil
class XTermBuffer(Buffer, XTerm):
    btype    = 'term'
    modename = 'pipe'
    termtype = 'xterm'
    #termtype = 'vt100'
    def __init__(self, cmd, args, name=None):
        XTerm.__init__(self)
        Buffer.__init__(self)
        self._name = name or '*XTerm*'
        self._pid, self._pty = pty.fork()
        if self._pid == 0:
            # child process
            os.execve(cmd, [cmd] + args, {'TERM': self.termtype})

        self._lock    = threading.Lock()
        self._towrite = ''
        self._done    = False
        self._set_nonblock(self._pty)
        self._thread = threading.Thread(target=self.pipe_read)
        self._thread.setDaemon(True)
        self._thread.start()


    def _w(self):
        return self.windows[0]
    def _get_height(self):
        return self._w().height
    def _get_width(self):
        return self._w().width
    # TERM STUFF
    def _term_insert(self, s):
        w = self._w()
        p = w.logical_cursor()
        if p.x == len(self.lines[p.y]):
            w.buffer.insert_string(p, s, act=ACT_NONE, force=True)
        else:
            w.buffer.overwrite_char(p, s, act=ACT_NONE, force=True)
    def term_do_clear(self):
        self.set_lines([''], force=True)
        self._meta = []
    def term_do_backspace(self):
        self._w().backward()
    def term_do_tab(self):
        self._term_insert('    ')
    def term_do_newline(self):
        w = self._w()
        p = w.logical_cursor()
        if p.y < len(self.lines) - 1:
            w.start_of_line()
            w.next_line()
        else:
            w.end_of_line()
            w.buffer.insert_string(w.logical_cursor(), "\n", act=ACT_NONE, force=True)
    def term_do_creturn(self):
        self._w().start_of_line()
    def term_do_delete(self):
        self._w().delete_right()
    def term_handle_print(self, c):
        #self._term_insert('%d ' % ord(c))
        self._term_insert(c)
    def term_handle_ctl(self, c):
        n = ord(c)
        if n == 8:
            self.term_do_backspace()
        elif n == 9:
            self.term_do_tab()
        elif n == 10:
            self.term_do_newline()
        elif n == 13:
            self.term_do_creturn()
        elif n == 27:
            self.term_do_esc(c)
        elif n == 127:
            self.term_do_delete()
        else:
            self._term_insert('%x' % n)

    def term_receive(self, s):
        for c in s:
            self.term_handle(c)

    # BUFFER STUFF
    def _set_nonblock(self, fd):
        flags = fcntl.fcntl(fd, fcntl.F_GETFL)
        fcntl.fcntl(fd, fcntl.F_SETFL, flags | os.O_NDELAY)

    def pipe_read(self):
        fd = self._pty
        try:
            while not self._done:
                if self._towrite:
                    ifd, ofd, efd = select.select([fd], [fd], [fd], 0.1)
                else:
                    ifd, ofd, efd = select.select([fd], [], [fd], 0.1)
                if ifd:
                    data = os.read(ifd[0], 1024)
                    self.term_receive(data)
                if ofd:
                    self._lock.acquire()
                    n = os.write(ofd[0], self._towrite)
                    self._towrite = self._towrite[n:]
                    self._lock.release()
                if efd:
                    raise Exception, "exception is ready: %s" % repr(efd)
        except (OSError, TypeError):
            pass
        os.close(fd)

    def pipe_write(self, s):
        self._lock.acquire()
        self._towrite += s
        self._lock.release()

    def name(self): return self._name
    def changed(self): return False
    def readonly(self): return True
    def undo(self, move, act): raise Exception, "invalid"
    def redo(self, move, act): raise Exception, "invalid"
    def reload(self): raise Exception, "invalid"