#!/usr/bin/env python2
#
#  Prepare an Ecmascript or API testcase file for execution.
#
#  For Ecmascript testcases:
#
#    - Lift a 'use strict' statement to top of file if present
#    - Add a prologue which handles engine differences
#    - Resolve include files
#
#  The prologue and includes are minified to a one-liner so that the line
#  numbers in the original test file are kept.
#
#  For C testcases:
#
#    - Add a prologue with testing utilities, includes, etc.
#

import os
import sys
import re
import tempfile
import subprocess
import optparse

re_include = re.compile(r'^/\*@include\s(.*?)\s*@\*/$')

def readFile(fn):
    f = open(fn, 'rb')
    data = f.read()
    f.close()
    return data

def writeFile(fn, data):
    f = open(fn, 'wb')
    f.write(data)
    f.close()

def stripTrailingNewlines(data):
    while data.endswith('\n'):
        data = data[:-1]
    return data

class TestcasePreparer:
    def __init__(self,
                 util_include_path=None,
                 minify_provider=None,
                 closure_jar_path=None,
                 uglifyjs_exe_path=None,
                 uglifyjs2_exe_path=None):
        self.util_include_path = util_include_path
        self.minify_provider = minify_provider
        self.closure_jar_path = closure_jar_path
        self.uglifyjs_exe_path = uglifyjs_exe_path
        self.uglifyjs2_exe_path = uglifyjs2_exe_path

    def prepApiTest(self, fn, data):
        # XXX: implement API testcase prepping
        return data

    def minifyClosure(self, fn):
        fh, absFn = tempfile.mkstemp(suffix='prep_temp')
        os.close(fh)

        rc = subprocess.call(['java', '-jar', self.closure_jar_path, '--js_output_file', absFn, fn ])
        if rc != 0:
            raise Exception('closure minify failed')

        res = readFile(absFn)
        os.unlink(absFn)
        return res

    def minifyUglifyJS(self, fn):
        fh, absFn = tempfile.mkstemp(suffix='prep_temp')
        os.close(fh)

        rc = subprocess.call([self.uglifyjs_exe_path, '-o', absFn, fn])
        if rc != 0:
            raise Exception('uglifyjs minify failed')

        res = readFile(absFn)
        os.unlink(absFn)
        return res

    def minifyUglifyJS2(self, fn):
        fh, absFn = tempfile.mkstemp(suffix='prep_temp')
        os.close(fh)

        rc = subprocess.call([self.uglifyjs2_exe_path, '-o', absFn, fn])
        if rc != 0:
            raise Exception('uglifyjs2 minify failed')

        res = readFile(absFn)
        os.unlink(absFn)
        return res

    def minifyOneLine(self, fn):
        # Closure is very slow to start so it's not ideal for test case use.
        # The only thing we really need is to make Ecmascript a one-liner.

        if self.minify_provider == 'closure':
            return self.minifyClosure(fn)
        elif self.minify_provider == 'uglifyjs':
            return self.minifyUglifyJS(fn)
        elif self.minify_provider == 'uglifyjs2':
            return self.minifyUglifyJS2(fn)
        else:
            raise Exception('no minifier')

    def prepEcmaPrologue(self, fn):
        return stripTrailingNewlines(self.minifyOneLine(fn))

    def prepEcmaInclude(self, fn):
        absFn = os.path.join(self.util_include_path, fn)
        return '/* INCLUDE: ' + fn + ' */ ' + stripTrailingNewlines(self.minifyOneLine(absFn))

    def prepEcmaTest(self, fn_in, fn_prologue, data):
        is_strict = False

        lines = []
        for line in data.split('\n'):
            if line.startswith('/'):
                m = re_include.match(line)
                if m is not None:
                    lines.append(self.prepEcmaInclude(m.group(1)))
                    continue
            elif line.startswith('"use strict"') or line.startswith("'use strict'"):
                # This is very approximate, but correct for current tests.
                is_strict = True

            lines.append(line)

        if fn_prologue is not None:
            # Prepend prologue to first line; if the program is strict
            # duplicate the 'use strict' declaration.
            lines[0] = self.prepEcmaPrologue(fn_prologue) + ' /*...*/ ' + lines[0]
            if is_strict:
                lines[0] = "'use strict'; " + lines[0]

        return '\n'.join(lines)

    def prepareTestcase(self, fn_in, fn_out, fn_prologue):
        data = readFile(fn_in)

        if fn_in.endswith('.c'):
            res = self.prepApiTest(fn_in, fn_prologue, data)
        elif fn_in.endswith('.js'):
            res = self.prepEcmaTest(fn_in, fn_prologue, data)
        else:
            raise Exception('invalid file (not .c or .js)')

        writeFile(fn_out, res)

def main():
    parser = optparse.OptionParser()
    parser.add_option('--input', dest='input', default=None)
    parser.add_option('--output', dest='output', default=None)
    parser.add_option('--prologue', dest='prologue', default=None)
    parser.add_option('--util-include-path', dest='util_include_path', default=None)
    parser.add_option('--minify-closure', dest='minify_closure', default=None)   # point to compiler.jar
    parser.add_option('--minify-uglifyjs', dest='minify_uglifyjs', default=None)  # point to uglifyjs exe
    parser.add_option('--minify-uglifyjs2', dest='minify_uglifyjs2', default=None)  # point to uglifyjs exe
    (opts, args) = parser.parse_args()

    if opts.input is None or opts.output is None:
        raise Exception('filename argument(s) missing (--input and/or --output)')
    if opts.util_include_path is None:
        raise Exception('missing util include path (--util-include-path)')

    fn_in = opts.input
    fn_out = opts.output
    fn_prologue = opts.prologue

    minify_provider = None
    if opts.minify_closure is not None:
        minify_provider = 'closure'
    elif opts.minify_uglifyjs is not None:
        minify_provider = 'uglifyjs'
    elif opts.minify_uglifyjs2 is not None:
        minify_provider = 'uglifyjs2'
    else:
        raise Exception('must provide a minifier (include files must be converted to one-liners)')

    preparer = TestcasePreparer(util_include_path=opts.util_include_path,
                                minify_provider=minify_provider,
                                closure_jar_path=opts.minify_closure,
                                uglifyjs_exe_path=opts.minify_uglifyjs,
                                uglifyjs2_exe_path=opts.minify_uglifyjs2)

    preparer.prepareTestcase(fn_in, fn_out, fn_prologue)

if __name__ == '__main__':
    main()