# -*- coding: utf-8 -*-

#-------------------------------------------------------------------------
# drawElements Quality Program utilities
# --------------------------------------
#
# Copyright 2015-2017 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
#-------------------------------------------------------------------------

import os
import sys
import hashlib

from . import registry

sys.path.append(os.path.join(os.path.dirname(__file__), ".."))

from build.common import *

BASE_URL = ""

class RegistrySource:
    def __init__(self, repository, filename, revision, checksum):
        self.repository = repository
        self.filename = filename
        self.revision = revision
        self.checksum = checksum

    def __hash__(self):
        return hash((self.repository, self.filename, self.revision, self.checksum))

    def __eq__(self, other):
        return (self.repository, self.filename, self.revision, self.checksum) == (other.repository, other.filename, other.revision, other.checksum)

    def getFilename (self):
        return os.path.basename(self.filename)

    def getCacheFilename (self):
        return "r%s-%s" % (self.revision, self.getFilename())

    def getChecksum (self):
        return self.checksum

    def getRevision (self):
        return self.revision

    def getRepo (self):
        return self.repository

    def getRevision (self):
        return self.revision

    def getFilename (self):
        return self.filename

def computeChecksum (data):
    dataFiltered = data.replace('\r','')
    hash = hashlib.sha256(dataFiltered.encode("utf-8")).hexdigest()
    return hash

def makeSourceUrl (repository, revision, filename):
    return "%s/%s/%s" % (repository, revision, filename)

def checkoutGit (repository, revision, fullDstPath):
    if not os.path.exists(fullDstPath):
        execute(["git", "clone", "--no-checkout", repository, fullDstPath])

    pushWorkingDir(fullDstPath)
    try:
        execute(["git", "fetch", repository, "+refs/heads/*:refs/remotes/origin/*"])
        execute(["git", "checkout", revision])
    finally:
        popWorkingDir()

def checkoutFile (repository, revision, filename, cacheDir):
    if sys.version_info < (3, 0):
        from urllib2 import urlopen
    else:
        from urllib.request import urlopen

    try:
        req = urlopen(makeSourceUrl(repository, revision, filename))
        data = req.read()
        if sys.version_info >= (3, 0):
            data = data.decode("utf-8")
    except IOError:
        fullDstPath = os.path.join(cacheDir, "git")

        checkoutGit(repository, revision, fullDstPath)
        f = open(os.path.join(fullDstPath, filename), "rt")
        data = f.read()
        f.close()
    except:
        print("Unexpected error:", sys.exc_info()[0])

    return data

def fetchFile (dstPath, repository, revision, filename, checksum, cacheDir):
    def writeFile (filename, data):
        f = open(filename, 'wt')
        f.write(data)
        f.close()

    if not os.path.exists(os.path.dirname(dstPath)):
        os.makedirs(os.path.dirname(dstPath))

    print("Fetching %s/%s@%s" % (repository, filename, revision))
    data = checkoutFile(repository, revision, filename, cacheDir)
    gotChecksum = computeChecksum(data)

    if checksum != gotChecksum:
        raise Exception("Checksum mismatch, expected %s, got %s" % (checksum, gotChecksum))

    writeFile(dstPath, data)

def checkFile (filename, checksum):
    def readFile (filename):
        f = open(filename, 'rt')
        data = f.read()
        f.close()
        return data

    if os.path.exists(filename):
        return computeChecksum(readFile(filename)) == checksum
    else:
        return False

g_registryCache = {}

def getRegistry (source):
    global g_registryCache

    if source in g_registryCache:
        return g_registryCache[source]

    cacheDir = os.path.join(os.path.dirname(__file__), "cache")
    cachePath = os.path.join(cacheDir, source.getCacheFilename())

    if not checkFile(cachePath, source.checksum):
        fetchFile(cachePath, source.getRepo(), source.getRevision(), source.getFilename(), source.getChecksum(), cacheDir)

    parsedReg = registry.parse(cachePath)

    g_registryCache[source] = parsedReg

    return parsedReg