import os, sys
import py

class TestStdCapture: 
    def getcapture(self, **kw):
        return py.io.StdCapture(**kw)

    def test_capturing_done_simple(self):
        cap = self.getcapture()
        print "hello world"
        print >>sys.stderr, "hello error"
        outfile, errfile = cap.done()
        assert outfile.read() == "hello world\n"
        assert errfile.read() == "hello error\n"

    def test_capturing_reset_simple(self):
        cap = self.getcapture()
        print "hello world"
        print >>sys.stderr, "hello error"
        out, err = cap.reset()
        assert out == "hello world\n"
        assert err == "hello error\n"

    def test_capturing_mixed(self):
        cap = self.getcapture(mixed=True)
        print "hello",
        print >>sys.stderr, "world",
        print >>sys.stdout, ".",
        out, err = cap.reset()
        assert out.strip() == "hello world ."
        assert not err

    def test_capturing_twice_error(self):
        cap = self.getcapture() 
        print "hello"
        cap.reset()
        py.test.raises(EnvironmentError, "cap.reset()")

    def test_capturing_modify_sysouterr_in_between(self):
        oldout = sys.stdout 
        olderr = sys.stderr 
        cap = self.getcapture()
        print "hello",
        print >>sys.stderr, "world",
        sys.stdout = py.std.StringIO.StringIO() 
        sys.stderr = py.std.StringIO.StringIO() 
        print "not seen" 
        print >>sys.stderr, "not seen"
        out, err = cap.reset()
        assert out == "hello"
        assert err == "world"
        assert sys.stdout == oldout 
        assert sys.stderr == olderr 

    def test_capturing_error_recursive(self):
        cap1 = self.getcapture() 
        print "cap1"
        cap2 = self.getcapture() 
        print "cap2"
        out2, err2 = cap2.reset()
        py.test.raises(EnvironmentError, "cap2.reset()")
        out1, err1 = cap1.reset() 
        assert out1 == "cap1\n"
        assert out2 == "cap2\n"
    
    def test_just_out_capture(self): 
        cap = self.getcapture(out=True, err=False)
        print >>sys.stdout, "hello"
        print >>sys.stderr, "world"
        out, err = cap.reset()
        assert out == "hello\n"
        assert not err 

    def test_just_err_capture(self): 
        cap = self.getcapture(out=False, err=True) 
        print >>sys.stdout, "hello"
        print >>sys.stderr, "world"
        out, err = cap.reset()
        assert err == "world\n"
        assert not out 

    def test_stdin_restored(self):
        old = sys.stdin 
        cap = self.getcapture(in_=True)
        newstdin = sys.stdin 
        out, err = cap.reset()
        assert newstdin != sys.stdin
        assert sys.stdin is old 

    def test_stdin_nulled_by_default(self):
        print "XXX this test may well hang instead of crashing"
        print "XXX which indicates an error in the underlying capturing"
        print "XXX mechanisms" 
        cap = self.getcapture()
        py.test.raises(IOError, "sys.stdin.read()")
        out, err = cap.reset()

class TestStdCaptureFD(TestStdCapture): 
    def getcapture(self, **kw): 
        return py.io.StdCaptureFD(**kw)

    def test_intermingling(self): 
        cap = self.getcapture()
        os.write(1, "1")
        print >>sys.stdout, 2,
        os.write(1, "3")
        os.write(2, "a")
        print >>sys.stderr, "b",
        os.write(2, "c")
        out, err = cap.reset()
        assert out == "123" 
        assert err == "abc" 

    def test_callcapture(self): 
        def func(x, y): 
            print x
            print >>py.std.sys.stderr, y
            return 42
      
        res, out, err = py.io.StdCaptureFD.call(func, 3, y=4) 
        assert res == 42 
        assert out.startswith("3") 
        assert err.startswith("4") 

def test_capture_no_sys(): 
    capsys = py.io.StdCapture()
    try:
        cap = py.io.StdCaptureFD(patchsys=False)
        print >>sys.stdout, "hello"
        print >>sys.stderr, "world"
        os.write(1, "1")
        os.write(2, "2")
        out, err = cap.reset()
        assert out == "1"
        assert err == "2"
    finally:
        capsys.reset()

def test_callcapture_nofd(): 
    def func(x, y): 
        os.write(1, "hello")
        os.write(2, "hello")
        print x
        print >>py.std.sys.stderr, y
        return 42
   
    res, out, err = py.io.StdCapture.call(func, 3, y=4) 
    assert res == 42 
    assert out.startswith("3") 
    assert err.startswith("4")