1 files changed, 147 insertions, 0 deletions
diff --git a/apkkit/base/index.py b/apkkit/base/index.py
new file mode 100644
index 0000000..ee0af9f
--- /dev/null
+++ b/apkkit/base/index.py
@@ -0,0 +1,147 @@
+"""Contains the Index class and related helper classes and functions."""
+
+from io import BytesIO
+import logging
+import os
+import requests
+import tarfile
+
+from apkkit.base.package import Package
+
+
+INDEX_LOGGER = logging.getLogger(__name__)
+
+
+class Index:
+    """The base index class."""
+
+    def __init__(self, packages=None, description=None, url=None, **kwargs):
+        """Initialise an Index object.
+
+        :param list packages:
+            The packages available in the repository this index represents.
+
+        :param str description:
+            (Recommended) The description of the repository this index
+            represents.  Typically, something like "system" or "user".
+
+        :param str url:
+            (Optional) The URL to download the index from.  All other
+            parameters are ignored if this is specified.
+        """
+
+        if url is not None:
+            self._url = url
+            resp = requests.get(url)
+            if resp.status_code != 200:
+                INDEX_LOGGER.error("could not download %s: %d (%r)", url,
+                                   resp.status_code, resp.text)
+            else:
+                self._fill_from_index_file(BytesIO(resp.content))
+        else:
+            if packages is None:
+                raise ValueError("Packages are required.")
+            self._pkgs = packages
+            self._desc = description
+
+        if len(kwargs) > 0:
+            INDEX_LOGGER.warning("unknown kwargs in Index: %r", kwargs)
+
+    @property
+    def description(self):
+        """The description of this repository."""
+        return self._desc
+
+    @property
+    def packages(self):
+        """The packages available in this repository."""
+        return list(self._pkgs)
+
+    @property
+    def origins(self):
+        """The names of all unique origin packages available in this repo."""
+        return {pkg.origin for pkg in self._pkgs}
+
+    def __repr__(self):
+        if self._url is not None:
+            return 'Index(url="{url}")'.format(url=self._url)
+        return 'Index(packages=<{num} packages>, description="{desc}")'.format(
+                num=len(self._pkgs), desc=self._desc)
+
+    def to_raw(self):
+        """Serialises this repository information into the APKINDEX format.
+
+        :returns str: The APKINDEX for this package.  Unicode str, ready to be
+                      written to a file.
+        """
+        raise NotImplemented("Not yet.")
+
+    def _fill_from_index_file(self, buf):
+        """Fill this `Index` object from the APKINDEX in `buf`."""
+        if len(getattr(self, '_pkgs', list())) > 0:
+            raise Exception("Attempt to fill an already filled Index")
+
+        pkgs = list()
+        params = {}
+        param_map = {'P': 'name', 'V': 'version', 'A': 'arch', 'o': 'origin',
+                     'T': 'description', 'p': 'provides', 'i': 'install_if',
+                     'D': 'depends', 'U': 'url', 'I': 'size', 'r': 'replaces',
+                     'L': 'license', 'q': 'replaces_priority', 'c': 'commit',
+                     'm': 'maintainer', 't': 'builddate'}
+        list_keys = {'p', 'D', 'i', 'r'}
+
+        tar = None
+
+        # assumption: "P" is the first line of each package.
+        try:
+            tar = tarfile.open(fileobj=buf)
+            real_buf = tar.extractfile('APKINDEX')
+        except:
+            real_buf = buf
+
+        for line in real_buf.readlines():
+            if not isinstance(line, str):
+                line = line.decode('utf-8')
+
+            # Skip comments.
+            if line[0] == '#':
+                continue
+
+            # separated by blank line
+            if line == "\n" and params.get('name', None) is not None:
+                pkgs.append(Package(**params))
+                params.clear()
+                continue
+
+            if line.find(':') == -1:
+                INDEX_LOGGER.warning('!!! malformed line? "%s" !!!', line)
+                continue
+
+            (key, value) = line.split(':', 1)
+            key = key.strip()
+            value = value.strip()
+
+            if key in param_map:
+                if key in list_keys:
+                    params[param_map[key]] = value.split(' ')
+                else:
+                    params[param_map[key]] = value
+            else:
+                INDEX_LOGGER.info('!!! unrecognised APKINDEX key %s !!!', key)
+
+        self._pkgs = pkgs
+
+    @classmethod
+    def from_raw(cls, buf):
+        """Create a new :py:class:`Index` object from an existing APKINDEX.
+
+        :param buf:
+            The buffer to read from (whether file, BytesIO, etc).
+
+        :returns:
+            A :py:class:`Index` object with the details from the APKINDEX.
+        """
+        idx = cls(packages=list())
+        idx._fill_from_index_file(buf)
+        return idx
+