import fnmatch
import glob
import hashlib
import logging
import mimetypes
import os
import re
import traceback

from datetime import datetime

from django.conf import settings
from django.http import Http404

from license_protected_downloads import(
    buildinfo,
    models,
)


log = logging.getLogger("llp.views")


def safe_path_join(base_path, *paths):
    """os.path.join with check that result is inside base_path.

    Checks that the generated path doesn't end up outside the target
    directory, so server accesses stay where we expect them.
    """

    target_path = os.path.join(base_path, *paths)

    if not target_path.startswith(base_path):
        return None

    if not os.path.normpath(target_path) == target_path.rstrip("/"):
        return None

    return target_path


def _check_special_eula(path):
    if glob.glob(path + ".EULA.txt.*"):
        return True


def _get_theme(path):
    eula = glob.glob(path + ".EULA.txt.*")
    vendor = os.path.splitext(eula[0])[1]
    return vendor[1:]


def _insert_license_into_db(digest, text, theme):
    if not models.License.objects.filter(digest=digest):
        l = models.License(digest=digest, text=text, theme=theme)
        l.save()


def is_protected(path):
    build_info = None
    max_index = 1
    base_path = path
    if not os.path.isdir(base_path):
        base_path = os.path.dirname(base_path)

    buildinfo_path = os.path.join(base_path, "BUILD-INFO.txt")
    open_eula_path = os.path.join(base_path, "OPEN-EULA.txt")
    eula_path = os.path.join(base_path, "EULA.txt")

    if os.path.isfile(buildinfo_path):
        try:
            build_info = buildinfo.BuildInfo(path)
        except buildinfo.IncorrectDataFormatException:
            # If we can't parse the BuildInfo, return [], which indicates no
            # license in dir_list and will trigger a 403 error in file_server.
            return []

        license_type = build_info.get("license-type")
        license_text = build_info.get("license-text")
        theme = build_info.get("theme")
        auth_groups = build_info.get("auth-groups")
        max_index = build_info.max_index
    elif os.path.isfile(open_eula_path):
        return "OPEN"
    elif os.path.isfile(eula_path):
        if re.search("snowball", path):
            theme = "stericsson"
        elif re.search("origen", path):
            theme = "samsung"
        else:
            theme = "linaro"
        license_type = "protected"
        license_file = os.path.join(settings.PROJECT_ROOT,
                                    'templates/licenses/' + theme + '.txt')
        auth_groups = False
        with open(license_file, "r") as infile:
            license_text = infile.read()
    elif _check_special_eula(path):
        theme = _get_theme(path)
        license_type = "protected"
        license_file = os.path.join(settings.PROJECT_ROOT,
                                    'templates/licenses/' + theme + '.txt')
        auth_groups = False
        with open(license_file, "r") as infile:
            license_text = infile.read()
    elif _check_special_eula(base_path + "/*"):
        return "OPEN"
    else:
        return []

    digests = []

    if license_type:
        if license_type == "open":
            return "OPEN"

        if auth_groups and not license_text:
            return "OPEN"
        elif license_text:
            for i in range(max_index):
                if build_info:
                    license_text = build_info.get("license-text", i)
                    theme = build_info.get("theme", i)
                digest = hashlib.md5(license_text).hexdigest()
                digests.append(digest)
                _insert_license_into_db(digest, license_text, theme)
        else:
            log.info("No license text or auth groups found: check the "
                     "BUILD-INFO file.")

    return digests


def _handle_wildcard(request, fullpath):
    path, name = os.path.split(fullpath)

    if not os.path.isdir(path):
        return None

    match = None
    for f in os.listdir(path):
        if fnmatch.fnmatch(f, name):
            if match:
                # change request.path so that the 404.html page can show
                # a descriptive error
                request.path = 'Multiple files match this expression'
                raise Http404
            match = os.path.join(path, f)
    return match


def _find_served_paths(path, request):
    served_paths = settings.SERVED_PATHS
    # if key is in request.GET["key"] then need to mod path and give
    # access to a per-key directory.
    if "key" in request.GET:
        key_details = models.APIKeyStore.objects.filter(key=request.GET["key"])
        if key_details:
            path = os.path.join(request.GET["key"], path)

            # Private uploads are in a separate path (or can be), so set
            # served_paths as needed.
            if not key_details[0].public:
                served_paths = [settings.UPLOAD_PATH]
    return served_paths, path


def test_path(path, request):
    """Check that path points to something we can serve up.
    """
    served_paths, path = _find_served_paths(path, request)
    for basepath in served_paths:
        fullpath = safe_path_join(basepath, path)
        if fullpath is None:
            raise Http404
        if os.path.isfile(fullpath):
            return ("file", fullpath)
        if os.path.isdir(fullpath):
            return ("dir", fullpath)

        fullpath = _handle_wildcard(request, fullpath)
        if fullpath:
            return ('file', fullpath)

    raise Http404


def _hidden_file(file_name):
    hidden_files = ["BUILD-INFO.txt", "EULA.txt", "HEADER.html",
                    "HOWTO_", "textile", ".htaccess", "licenses"]
    for pattern in hidden_files:
        if re.search(pattern, file_name):
            return True
    return False


def _sort_artifacts(a, b):
    '''Ensures directory listings follow our ordering rules for artifacts.

    If the directory is all numbers it sorts them numerically. The "latest"
    entry will always be the first entry. Else use standard sorting.
    '''
    a = a.file_name
    b = b.file_name
    try:
        return cmp(int(a), int(b))
    except:
        pass
    if a == 'latest':
        return -1
    elif b == 'latest':
        return 1

    return cmp(a, b)


def _sizeof_fmt(num):
    ''' Returns in human readable format for num.
    '''
    if num < 1024 and num > -1024:
        return str(num)
    num /= 1024.0
    for x in ['K', 'M', 'G']:
        if num < 1024.0 and num > -1024.0:
            return "%3.1f%s" % (num, x)
        num /= 1024.0
    return "%3.1f%s" % (num, 'T')


class Artifact(object):
    def __init__(self, urlbase, file_name, human_readable, local_path):
        self.human_readable = human_readable
        self.file_name = file_name
        self.urlbase = urlbase
        self.full_path = os.path.join(local_path, file_name)

    def url(self):
        url = self.urlbase
        if url:
            if url[0] != '/':
                url = '/' + url
            if url[-1] != '/':
                url += '/'
        else:
            url = '/'
        return url + self.file_name

    def get_type(self):
        if os.path.isdir(self.full_path):
            return 'folder'
        else:
            mtype = mimetypes.guess_type(self.full_path)[0]
            if self.human_readable:
                if mtype is None:
                    mtype = 'other'
                elif mtype.split('/')[0] == 'text':
                    mtype = 'text'
            return mtype

    def get_size(self):
        size = 0
        # ensure the file we are looking at exists (not broken symlink)
        if os.path.exists(self.full_path):
            size = os.path.getsize(self.full_path)
            if self.human_readable:
                size = _sizeof_fmt(size)
        return size

    def get_mtime(self):
        mtime = 0
        # ensure the file we are looking at exists (not broken symlink)
        if os.path.exists(self.full_path):
            mtime = os.path.getmtime(self.full_path)
            if self.human_readable:
                mtime = datetime.fromtimestamp(mtime)
                mtime = mtime.strftime('%d-%b-%Y %H:%M')
        return mtime

    def get_listing(self):
        if os.path.isdir(self.full_path):
            ldl = []
        else:
            try:
                ldl = is_protected(self.full_path)
            except Exception as e:
                print("Invalid BUILD-INFO.txt for %s: %s" % (
                    self.full_path, repr(e)))
                traceback.print_exc()
                ldl = "INVALID"
        ll = models.License.objects.all_with_hashes(ldl)
        return {
            'name': self.file_name,
            'size': self.get_size(),
            'type': self.get_type(),
            'mtime': self.get_mtime(),
            'license_digest_list': ldl,
            'license_list': ll,
            'url': self.url(),
        }


def dir_list(url, path, human_readable=True):

    artifacts = []
    if os.path.exists(path):
        artifacts = [Artifact(url, x, human_readable, path)
                     for x in os.listdir(path)]
    artifacts.sort(_sort_artifacts)

    listing = []
    for artifact in artifacts:
        if not _hidden_file(artifact.file_name):
            listing.append(artifact.get_listing())
    return listing