#!/usr/bin/env python
#
# trigger_build.py - Trigger a package build and deployment on one or more FSL
# conda recipe repositories.
#
# Author: Paul McCarthy <pauldmccarthy@gmail.com>
#


import                          sys
import os.path               as op
import functools             as ft
import textwrap              as tw
import                          argparse
import                          datetime
import multiprocessing.dummy as mp

from   fsl_ci.recipe   import  get_recipe_variable
from   fsl_ci.platform import  get_platform_ids
from   fsl_ci.conda    import  load_meta_yaml
import fsl_ci.gitlab   as      gitlab
from   fsl_ci.gitlab   import (trigger_job,
                               get_variables,
                               download_file,
                               find_latest_job,
                               trigger_pipeline,
                               wait_on_pipeline)


gitlab.VERBOSE = False


SERVER_URL = 'https://git.fmrib.ox.ac.uk'
"""Default gitlab instance URL, if not specified on the command.line."""


def now():
    """Returns the current time as a string. """
    return datetime.datetime.now().strftime('%H:%M:%S')


def get_revision(recipe_path, server, token):
    """Return the value of the FSLCONDA_REVISION variable on the given
    conda recipe repository, or None if it is not set.

    The returned revision is only used for staging builds.
    """

    meta         = download_file(recipe_path, 'meta.yaml', server, token)
    project_repo = get_recipe_variable(meta, 'repository')
    variables    = get_variables(recipe_path, server, token)

    # meta.yaml not parseable
    if project_repo is None:
        return None

    # externally hosted project
    if SERVER_URL not in project_repo:
        return None

    # Build off FSLCONDA_REVISION if set, otherwise
    # build off master (remember this only affects
    # staging builds)
    rev = variables.get('FSLCONDA_REVISION', None)

    if rev is not None: return rev
    else:               return 'master'


def trigger_build(project, server, token, production):
    """Triggers a pipeline on the master branch of project and waits for it
    to complete.
    """

    rev = get_revision(project, server, token)

    if production:
        channel   = 'production'
        variables = {}
    else:
        channel   = 'staging'
        variables = {'STAGING' : 'true'}

        if rev is not None:
            variables['FSLCONDA_REVISION'] = rev

    try:
        pipeline = trigger_pipeline(
            project, 'master', server, token, variables)
    except Exception:
        return None

    pid = pipeline['id']

    print(f'{now()} Pipeline triggered on {project} ({channel} build) '
          f'- see {pipeline["web_url"]}')

    try:
        status = wait_on_pipeline(project, pid, server, token)
    except Exception:
        return None

    print(f'{now()} Build pipeline for {project} has finished: {status}')

    if status != 'manual':
        return None

    return pid


def trigger_deploy(project, pid, server, token, production):
    """Triggers the most recently created manual 'deploy-conda-package' job,
    and waits for it to complete.
    """

    # trigger_build returns None
    # if the build failed
    if pid is None:
        return False

    # deployment to staging/production gets set at
    # build time, so we don't need to pass the STAGING
    # variable here, like we do in trigger_build
    if production: channel = 'production'
    else:          channel = 'staging'

    meta      = download_file(project, 'meta.yaml', server, token)
    meta      = load_meta_yaml(meta)
    platforms = get_platform_ids(meta)

    print(f'{now()} Triggering deploy-{platforms}-conda-package jobs '
          f'on {project} (deploying to {channel} channel)')

    try:
        jids = []
        for platform in platforms:
            jids.extend(find_latest_job(
                project, server, token, f'deploy-{platform}-conda-package', 1))
        for j in jids:
            trigger_job(project, j['id'], server, token)

        status = wait_on_pipeline(project, pid, server, token)
        print(f'{now()} Deploy job {project} has finished: {status}')
        return True
    except Exception as e:
        print(f'Error triggering deploy job on {project}: {e}')
        return False


def parseArgs(argv=None):
    """Parses and returns command line arguments. """

    name   = op.basename(__file__)
    usage  = f'Usage: {name} -t <token> [options] project [project ...]'
    desc  = tw.dedent("""
    Trigger a package build and deployment on
    one or more FSL conda recipe repositories.
    """).strip()

    helps = {
        'token'      : 'Gitlab API access token with read+write access',
        'server'     :  f'Gitlab server (default: {SERVER_URL})',
        'project'    : 'Project(s) to build',
        'production' : 'Build production/stable version '
                       '(default: label built package as staging/development)',
        'sequential' : 'Build projects sequentially (default: build in '
                       'parallel',
    }

    parser = argparse.ArgumentParser(usage=usage, description=desc)
    parser.add_argument('project', nargs='+',
                        help=helps['project'])
    parser.add_argument('-s', '--server', default=SERVER_URL,
                        help=helps['server'])
    parser.add_argument('-t', '--token', required=True,
                        help=helps['token'])
    parser.add_argument('-p', '--production', action='store_true',
                        help=helps['production'])
    parser.add_argument('-q', '--sequential', action='store_true',
                        help=helps['sequential'])

    return parser.parse_args(argv)


def main(argv=None):
    """Trigger builds on all listed projects concurrently, and wait for them
    all to complete or fail.
    """

    args     = parseArgs(argv)
    projects = args.project
    build    = ft.partial(trigger_build,
                          server=args.server,
                          token=args.token,
                          production=args.production)
    deploy   = ft.partial(trigger_deploy,
                          server=args.server,
                          token=args.token,
                          production=args.production)
    result   = True

    if args.sequential:
        for project in projects:
            pid = build(project)
            if not deploy(project, pid):
                result = False
    else:
        pool   = mp.Pool(len(projects))
        pids   = pool.map(build, projects)
        result = all(pool.starmap(deploy, zip(projects, pids)))
        pool.close()
        pool.join()

    return 0 if result else 1


if __name__  == '__main__':
    sys.exit(main())