#!/usr/bin/python3
#
# Testcase runner for NetSurf projects
#
# Usage: testrunner <builddir> <testdir> <prefix> [<executable extension>]
#
# Operates upon INDEX files described in the README.
# Locates and executes testcases, feeding data files to programs 
# as appropriate.
# Logs testcase output to file.
# Aborts test sequence on detection of error.
#

import os
import sys
import queue
import threading
import subprocess

global builddir
global directory
global prefix
global exeext

if len(sys.argv) < 4:
    print("Usage: testrunner.pl <builddir> <testdir> <prefix> [<exeext>]")
    sys.exit(1)

# Get directories
builddir = sys.argv[1]
directory = sys.argv[2]
prefix = sys.argv[3]

# Get EXE extension (if any)
exeext = None
if len(sys.argv) > 4:
    exeext = sys.argv[4]

# Open log file and /dev/null
LOG = open(os.path.join(builddir, "testlog"), "w")


def run_test(test_exe, test_data):
    io_q = queue.Queue()

    def output_collector(identifier, stream):
        for line in stream:
            io_q.put((identifier, line.decode("utf-8").rstrip()))

        if not stream.closed:
            stream.close()

    # Run the test
    proc = subprocess.Popen([test_exe, test_data],
            stdout=subprocess.PIPE, stderr=subprocess.PIPE)

    # Threads for sticking output into queue
    tout = threading.Thread(target=output_collector, name='stdout-watcher',
            args=('STDOUT', proc.stdout))
    terr = threading.Thread(target=output_collector, name='stderr-watcher',
            args=('STDERR', proc.stderr))

    tout.start()
    terr.start()

    # Wait for test to finish
    ret = proc.wait()

    # And join the output collector threads
    tout.join()
    terr.join()

    # If last line of STDOUT is "PASS", then the test passed
    last_line = None

    # The STDERR output is just collected up and put at the end of LOG
    error_lines = []

    while not io_q.empty():
        identifier, line = io_q.get()
        if identifier == "STDOUT":
            LOG.write("%s\n" % line)
            last_line = line
        else:
            error_lines += line

    # Check for test process returning error
    if ret != 0:
        LOG.write("    FAIL: Exit status %i\n" % ret)
        last_line = "FAIL"

    # Dump stderr to log
    for error_line in error_lines:
        LOG.write("%s\n" % line)

    if not last_line == "PASS":
        last_line = "FAIL"

    # Print rest result
    print(last_line)
    return

# Open testcase index
with open(os.path.join(directory, "INDEX"), "r") as TINDEX:
    # Parse testcase index, looking for testcases
    for line in TINDEX:
        # Skip comments
        if line[0] == '#' or line.isspace():
            continue

        # Found one; decompose
        decomposed = list(filter(None, line.split('\t')))

        # Strip whitespace
        test = decomposed[0].strip()
        desc = decomposed[1].strip()
        data = None
        if len(decomposed) > 2:
            data = decomposed[2].strip()

        # Append prefix & EXE extension to binary name
        test = prefix + test
        if exeext:
            test += exeext

        print("Test: " + desc)

        if data:
            # Testcase has external data files

            # Open datafile index
            with open(os.path.join(directory, "data/" + data + "/INDEX"), "r") as DINDEX:
                # Parse datafile index, looking for datafiles
                for dline in DINDEX:
                    if dline[0] == '#' or dline.isspace():
                        continue

                    # Found one; decompose
                    ddecomposed = list(filter(None, dline.split('\t')))

                    # Strip whitespace
                    dtest = ddecomposed[0].strip()
                    ddesc = ddecomposed[1].strip()

                    LOG.write("Running %s %s\n" % (
                            os.path.join(builddir, test),
                            os.path.join(directory, "data/" + data + "/" + dtest)))

                    # Make message fit on an 80 column terminal
                    msg = "    ==> " + test + " [" + data + "/" + dtest + "]"
                    msg += "." * (80 - len(msg) - 8)

                    sys.stdout.write(msg)

                    # Run testcase
                    run_test(os.path.join(builddir, test),
                             os.path.join(directory, "data/" + data + "/" + dtest))
        else:
            # Testcase has no external data files
            LOG.write("Running %s\n" % (os.path.join(builddir, test)))

            # Make message fit on an 80 column terminal
            msg = "    ==> " + test
            msg += "." * (80 - len(msg) - 8)

            sys.stdout.write(msg)

            # Run testcase
            run_test(os.path.join(builddir, test))

        print("")