import optparse
import logging
import os

import wizard
from wizard import deploy
from wizard import util
from wizard import shell
from wizard import cache
from wizard.command import _base
from wizard.command import migrate

def main(argv, global_options):
    options, args = parse_args(argv)
    app = args[0]
    base_args = calculate_base_args(options)
    sh = make_shell(options)
    seen = make_cache(options)
    my_uid = os.getuid() # to see if we have root
    # loop stuff
    errors = {}
    uid = None
    for line in deploy.getInstallLines(global_options):
        # validate and filter the deployments
        try:
            d = deploy.Deployment.parse(line)
        except deploy.DeploymentParseError, deploy.NoSuchApplication:
            continue
        name = d.getApplication().name
        if name != app: continue
        if d.location in seen:
            continue
        # actual meat
        def make_on_pair(d):
            def on_success(stdout, stderr):
                seen.add(d.location)
            def on_error(e):
                if e.name == "wizard.command.migrate.AlreadyMigratedError":
                    seen.add(d.location)
                    logging.info("Skipped already migrated %s" % d.location)
                else:
                    name = e.name
                    if name not in errors: errors[name] = []
                    errors[name].append(d)
                    logging.error("%s in %s" % (name, d.location))
            return (on_success, on_error)
        on_success, on_error = make_on_pair(d)
        if not my_uid:
            uid = get_dir_uid(d.location)
        sh.wait() # wait for a parallel processing slot to be available
        sh.callAsUser(shell.wizard, "migrate", d.location, *base_args,
                      uid=uid, on_success=on_success, on_error=on_error)
    sh.join()
    for name, deploys in errors.items():
        logging.warning("%s from %d installs" % (name, len(deploys)))

def parse_args(argv):
    usage = """usage: %prog massmigrate [ARGS] APPLICATION

Mass migrates an application to the new repository format.
Essentially equivalent to running '%prog migrate' on all
autoinstalls for a particular application found by parallel-find,
but with advanced reporting.

When doing an actual run, it is recommended to use --cache to
be able to resume gracefully (without it, massmigrate must
stat every install to find out if it migrated it yet).

This command is intended to be run as root on a server with
the scripts AFS patch.  You may run it in userspace for
testing purposes, but then you MUST NOT run this on untrusted
repositories.
"""
    parser = _base.WizardOptionParser(usage)
    parser.add_option("--no-parallelize", dest="no_parallelize", action="store_true",
            default=False, help="Turn off parallelization")
    parser.add_option("--dry-run", dest="dry_run", action="store_true",
            default=False, help="Print commands that would be run. Implies --no-parallelize")
    parser.add_option("--max", dest="max",
            default=10, help="Maximum subprocesses to run concurrently")
    parser.add_option("--cache", dest="cache",
            default=None, help="Cache file to read/write paths of already processed installs. These will be skipped.")
    options, args, = parser.parse_all(argv)
    if len(args) > 1:
        parser.error("too many arguments")
    elif not args:
        parser.error("must specify application to migrate")
    if options.dry_run:
        options.no_parallelize = True
    return options, args

def calculate_base_args(options):
    base_args = _base.makeBaseArgs(options, dry_run="--dry-run")
    if not options.debug:
        base_args.append("--quiet")
    return base_args

def make_shell(options):
    if options.no_parallelize:
        sh = shell.DummyParallelShell()
    else:
        sh = shell.ParallelShell(max=int(options.max))
    return sh

def make_cache(options):
    if options.cache:
        seen = cache.Cache(options.cache)
    else:
        seen = cache.DummyCache()
    return seen