'''
Tests for fileinput module.
Nick Mathewson
'''

import unittest
from test.test_support import verbose, TESTFN, run_unittest
from test.test_support import unlink as safe_unlink
import sys, re
from StringIO import StringIO
from fileinput import FileInput, hook_encoded

# The fileinput module has 2 interfaces: the FileInput class which does
# all the work, and a few functions (input, etc.) that use a global _state
# variable.  We only test the FileInput class, since the other functions
# only provide a thin facade over FileInput.

# Write lines (a list of lines) to temp file number i, and return the
# temp file's name.
def writeTmp(i, lines, mode='w'):  # opening in text mode is the default
    name = TESTFN + str(i)
    f = open(name, mode)
    f.writelines(lines)
    f.close()
    return name

def remove_tempfiles(*names):
    for name in names:
        safe_unlink(name)

class BufferSizesTests(unittest.TestCase):
    def test_buffer_sizes(self):
        # First, run the tests with default and teeny buffer size.
        for round, bs in (0, 0), (1, 30):
            try:
                t1 = writeTmp(1, ["Line %s of file 1\n" % (i+1) for i in range(15)])
                t2 = writeTmp(2, ["Line %s of file 2\n" % (i+1) for i in range(10)])
                t3 = writeTmp(3, ["Line %s of file 3\n" % (i+1) for i in range(5)])
                t4 = writeTmp(4, ["Line %s of file 4\n" % (i+1) for i in range(1)])
                self.buffer_size_test(t1, t2, t3, t4, bs, round)
            finally:
                remove_tempfiles(t1, t2, t3, t4)

    def buffer_size_test(self, t1, t2, t3, t4, bs=0, round=0):
        pat = re.compile(r'LINE (\d+) OF FILE (\d+)')

        start = 1 + round*6
        if verbose:
            print '%s. Simple iteration (bs=%s)' % (start+0, bs)
        fi = FileInput(files=(t1, t2, t3, t4), bufsize=bs)
        lines = list(fi)
        fi.close()
        self.assertEqual(len(lines), 31)
        self.assertEqual(lines[4], 'Line 5 of file 1\n')
        self.assertEqual(lines[30], 'Line 1 of file 4\n')
        self.assertEqual(fi.lineno(), 31)
        self.assertEqual(fi.filename(), t4)

        if verbose:
            print '%s. Status variables (bs=%s)' % (start+1, bs)
        fi = FileInput(files=(t1, t2, t3, t4), bufsize=bs)
        s = "x"
        while s and s != 'Line 6 of file 2\n':
            s = fi.readline()
        self.assertEqual(fi.filename(), t2)
        self.assertEqual(fi.lineno(), 21)
        self.assertEqual(fi.filelineno(), 6)
        self.assertFalse(fi.isfirstline())
        self.assertFalse(fi.isstdin())

        if verbose:
            print '%s. Nextfile (bs=%s)' % (start+2, bs)
        fi.nextfile()
        self.assertEqual(fi.readline(), 'Line 1 of file 3\n')
        self.assertEqual(fi.lineno(), 22)
        fi.close()

        if verbose:
            print '%s. Stdin (bs=%s)' % (start+3, bs)
        fi = FileInput(files=(t1, t2, t3, t4, '-'), bufsize=bs)
        savestdin = sys.stdin
        try:
            sys.stdin = StringIO("Line 1 of stdin\nLine 2 of stdin\n")
            lines = list(fi)
            self.assertEqual(len(lines), 33)
            self.assertEqual(lines[32], 'Line 2 of stdin\n')
            self.assertEqual(fi.filename(), '<stdin>')
            fi.nextfile()
        finally:
            sys.stdin = savestdin

        if verbose:
            print '%s. Boundary conditions (bs=%s)' % (start+4, bs)
        fi = FileInput(files=(t1, t2, t3, t4), bufsize=bs)
        self.assertEqual(fi.lineno(), 0)
        self.assertEqual(fi.filename(), None)
        fi.nextfile()
        self.assertEqual(fi.lineno(), 0)
        self.assertEqual(fi.filename(), None)

        if verbose:
            print '%s. Inplace (bs=%s)' % (start+5, bs)
        savestdout = sys.stdout
        try:
            fi = FileInput(files=(t1, t2, t3, t4), inplace=1, bufsize=bs)
            for line in fi:
                line = line[:-1].upper()
                print line
            fi.close()
        finally:
            sys.stdout = savestdout

        fi = FileInput(files=(t1, t2, t3, t4), bufsize=bs)
        for line in fi:
            self.assertEqual(line[-1], '\n')
            m = pat.match(line[:-1])
            self.assertNotEqual(m, None)
            self.assertEqual(int(m.group(1)), fi.filelineno())
        fi.close()

class FileInputTests(unittest.TestCase):
    def test_zero_byte_files(self):
        try:
            t1 = writeTmp(1, [""])
            t2 = writeTmp(2, [""])
            t3 = writeTmp(3, ["The only line there is.\n"])
            t4 = writeTmp(4, [""])
            fi = FileInput(files=(t1, t2, t3, t4))

            line = fi.readline()
            self.assertEqual(line, 'The only line there is.\n')
            self.assertEqual(fi.lineno(), 1)