import os, commands, re, tempfile
from subprocess import Popen, PIPE, STDOUT

import buffer, default, dirutil, regex, term, util, window
from point import Point

from method import Method, Argument

class Exec(Method):
    '''Execute a command in a shell and put the output in a new buffer'''
    show_success = True
    args = [Argument('cmd', prompt="Exec: ", datatype='shell')]
    def _doit(self, w, path, cmd, cmdname=None, bufname=None, cmddir=None, opts={}):
        if cmddir:
            cmd = "cd %r && %s" % (cmddir, cmd)
        d = dict(opts)
        if path:
            d['path'] = path
        try:
            cmd = cmd % d
        except:
            pass

        if bufname is None: bufname = '*%s*' % self.name.title()
        if cmdname is None: cmdname = cmd.split(None, 1)[0]

        p      = Popen(cmd, shell=True, stdout=PIPE, stderr=STDOUT)
        output = p.stdout.read()
        result = p.wait()
        status = os.WEXITSTATUS(result)

        if not os.WIFEXITED(result):
            err    = True
            errmsg = "%s: killed by signal %r" % (cmdname, os.WTERMSIG(result))
        elif status != 0:
            err    = True
            errmsg = "%s: failed with status %r" % (cmdname, status)
        else:
            err    = False
            errmsg = "%s: ok" % (cmdname,)

        if output:
            switch_to = err or self.show_success
            w.application.data_buffer(bufname, output, switch_to=switch_to)
        w.set_error(errmsg)
        
    def _execute(self, w, **vargs):
        if w.buffer.btype == 'dir':
            name = dirutil.resolve_name(w)
            path = dirutil.resolve_path(w)
            self._doit(w, path, vargs['cmd'])
            dirutil.find_name(w, name)
        elif hasattr(w.buffer, 'path'):
            path = w.buffer.path
            self._doit(w, path, vargs['cmd'])
        else:
            self._doit(w, None, vargs['cmd'])

class Man(Exec):
    '''Execute a command in a shell and put the output in a new buffer'''
    args = [Argument('name', prompt="Program: ")]
    def _execute(self, w, **vargs):
        name   = vargs['name']
        cmd    = 'man %r' % name
        p      = Popen(cmd, shell=True, stdout=PIPE, stderr=STDOUT)
        output = p.stdout.read()
        result = p.wait()
        status = os.WEXITSTATUS(result)
        if not os.WIFEXITED(result):
            err    = True
            errmsg = "man: killed by signal %r" % os.WTERMSIG(result)
        elif status != 0:
            err    = True
            errmsg = "man: failed with status %r" % status
        else:
            err    = False
            errmsg = "man: ok"
        if output:
            xterm = term.XTerm()
            output = xterm.term_filter(output)
            switch_to = err or self.show_success
            w.application.data_buffer('*Manpage*', output, switch_to=switch_to)
        w.set_error(errmsg)

class Pipe(Method):
    '''Pipe the buffer's contents through the command, and display the output in a new buffer'''
    args = [Argument('cmd', datatype="shell", prompt="Pipe: ")]
    def _parse(self, w, **vargs):
        # return 3 things: prog name, cmd, and whether to use the shell
        m = regex.shell_command.match(vargs['cmd'])
        if m:
            prog = m.group(0)
            return (prog, vargs['cmd'], True)
        else:
            return (None, None, False)

    def _display(self, w, data, status, prog, cmd, shell):
        lines = data.split('\n')
        if lines and lines[-1] == '':
            lines = lines[:-1]
        if status == 0 and len(lines) == 1:
            w.set_error("%s output: %r" % (prog, lines[0]))
        else:
            bufname = '*%s*' % self.name.title()
            w.application.data_buffer(bufname, data, switch_to=True)
            w.set_error("%s exited with status %d" % (prog, status))

    def _execute(self, w, **vargs):
        (prog, cmd, shell) = self._parse(w, **vargs)
        if prog is None or not cmd:
            return
        self._dopipe(w, prog, cmd, shell)

    def _dopipe(self, w, prog, cmd, shell):
        pipe = Popen(cmd, shell=shell, stdin=PIPE, stdout=PIPE, stderr=STDOUT)
        pid = pipe.pid

        indata = w.buffer.make_string()
        pipe.stdin.write(indata)
        pipe.stdin.close()

        outdata = pipe.stdout.read()
        status  = pipe.wait() >> 8

        self._display(w, outdata, status, prog, cmd, shell)

class Grep(Pipe):
    '''Grep the buffer's contents for instances of a pattern, and display them in a new buffer'''
    args = [Argument('pattern', datatype="str", prompt="Pattern: ")]
    def _parse(self, w, **vargs):
        return ('grep', ('grep', '-E', '-n', vargs['pattern']), False)
class Sed(Pipe):
    '''Push the buffer's contents through a sed expression'''
    args = [Argument('expression', datatype="str", prompt="Expression: ")]
    def _parse(self, w, **vargs):
        return ('grep', ('sed', '-r', '-e', vargs['expression']), False)

class Interact(Method):
    '''Interact with a program via a PTY'''
    args = [Argument('bname', datatype="str", prompt="Buffer Name: ",
                     default=default.build_constant('*Interact*')),
            Argument('cmd', datatype="shell", prompt="Command: ",
                     default=default.build_constant('bash'))]
    def _execute(self, w, **vargs):
        bname = vargs['bname']
        cmd   = vargs['cmd']
        a = w.application
        a.close_buffer_by_name(bname)
        b = buffer.emul.XTermBuffer(a, 'bash', ['-c', cmd], name=bname)
        a.add_buffer(b)
        window.Window(b, a)
        if a.window().buffer is not b:
            a.switch_buffer(b)