#!/usr/bin/python
"""This scrip takes a directory or a http base url to a mirror and imports all
packages contained. It has rather strong assumptions on the working directory.
"""

import gzip
import errno
import io
import multiprocessing
import optparse
import os
import subprocess
import tempfile
import urllib

import concurrent.futures
from debian import deb822
from debian.debian_support import version_compare
import sqlalchemy

from dedup.utils import configure_database_engine

from readyaml import readyaml

def process_http(pkgs, url):
    pkglist = urllib.urlopen(url + "/dists/sid/main/binary-amd64/Packages.gz").read()
    pkglist = gzip.GzipFile(fileobj=io.BytesIO(pkglist)).read()
    pkglist = io.BytesIO(pkglist)
    pkglist = deb822.Packages.iter_paragraphs(pkglist)
    for pkg in pkglist:
        name = pkg["Package"]
        if name in pkgs and \
                version_compare(pkgs[name]["version"], pkg["Version"]) > 0:
            continue
        pkgs[name] = dict(version=pkg["Version"],
                          filename="%s/%s" % (url, pkg["Filename"]),
                          sha256hash=pkg["SHA256"])

def process_file(pkgs, filename):
    base = os.path.basename(filename)
    if not base.endswith(".deb"):
        raise ValueError("filename does not end in .deb")
    parts = base.split("_")
    if len(parts) != 3:
        raise ValueError("filename not in form name_version_arch.deb")
    name, version, _ = parts
    version = urllib.unquote(version)
    if name in pkgs and version_compare(pkgs[name]["version"], version) > 0:
        return
    pkgs[name] = dict(version=version, filename=filename)

def process_dir(pkgs, d):
    for entry in os.listdir(d):
        try:
            process_file(pkgs, os.path.join(d, entry))
        except ValueError:
            pass

def process_pkg(name, pkgdict, outpath):
    filename = pkgdict["filename"]
    print("importing %s" % filename)
    importcmd = ["python", "importpkg.py"]
    if "sha256hash" in pkgdict:
        importcmd.extend(["-H", pkgdict["sha256hash"]])
    if filename.startswith("http://"):
        with open(outpath, "w") as outp:
            dl = subprocess.Popen(["curl", "-s", filename],
                                  stdout=subprocess.PIPE, close_fds=True)
            imp = subprocess.Popen(importcmd, stdin=dl.stdout, stdout=outp,
                                   close_fds=True)
            if imp.wait():
                raise ValueError("importpkg failed")
            if dl.wait():
                raise ValueError("curl failed")
    else:
        with open(filename) as inp:
            with open(outpath, "w") as outp:
                subprocess.check_call(importcmd, stdin=inp, stdout=outp,
                                      close_fds=True)
    print("preprocessed %s" % name)

def main():
    parser = optparse.OptionParser()
    parser.add_option("-n", "--new", action="store_true",
                      help="avoid reimporting same versions")
    parser.add_option("-p", "--prune", action="store_true",
                      help="prune packages old packages")
    parser.add_option("-d", "--database", action="store",
                      default="sqlite:///test.sqlite3",
                      help="location of the database")
    options, args = parser.parse_args()
    tmpdir = tempfile.mkdtemp(prefix=b"debian-dedup")
    db = sqlalchemy.create_engine(options.database)
    configure_database_engine(db)
    e = concurrent.futures.ThreadPoolExecutor(multiprocessing.cpu_count())
    pkgs = {}
    for d in args:
        print("processing %s" % d)
        if d.startswith("http://"):
            process_http(pkgs, d)
        elif os.path.isdir(d):
            process_dir(pkgs, d)
        else:
            process_file(pkgs, d)

    print("reading database")
    with db.begin() as conn:
        cur = conn.execute("SELECT name, version FROM package;")
        knownpkgs = dict((row[0], row[1]) for row in cur.fetchall())
    distpkgs = set(pkgs.keys())
    if options.new:
        for name in distpkgs:
            if name in knownpkgs and version_compare(pkgs[name]["version"],
                    knownpkgs[name]) <= 0:
                del pkgs[name]
    knownpkgs = set(knownpkgs)

    with e:
        fs = {}
        for name, pkg in pkgs.items():
            outpath = os.path.join(tmpdir, name)
            fs[e.submit(process_pkg, name, pkg, outpath)] = name

        for f in concurrent.futures.as_completed(fs.keys()):
            name = fs[f]
            if f.exception():
                print("%s failed to import: %r" % (name, f.exception()))
                continue
            inf = os.path.join(tmpdir, name)
            print("sqlimporting %s" % name)
            with open(inf) as inp:
                try:
                    with db.begin() as conn:
                        readyaml(conn, inp)
                except Exception as exc:
                    print("%s failed sql with exception %r" % (name, exc))
                else:
                    os.unlink(inf)

    if options.prune:
        delpkgs = knownpkgs - distpkgs
        if delpkgs:
            print("clearing packages %s" % " ".join(delpkgs))
            with db.begin() as conn:
                conn.execute(sqlalchemy.text("DELETE FROM package WHERE name = :name;"),
                             [dict(name=pkg) for pkg in delpkgs])
                # Tables content, dependency and sharing will also be pruned
                # due to ON DELETE CASCADE clauses.
    try:
        os.rmdir(tmpdir)
    except OSError as err:
        if err.errno != errno.ENOTEMPTY:
            raise
        print("keeping temporary directory %s due to failed packages %s" %
              (tmpdir, " ".join(os.listdir(tmpdir))))

if __name__ == "__main__":
    main()