# Copyright 2017 The Bazel Authors. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Implementation of the ts_web_test rule."""

load("@build_bazel_rules_nodejs//internal:node.bzl",
    "sources_aspect",
    "expand_path_into_runfiles",
)

_CONF_TMPL = "//internal/karma:karma.conf.js"
# TODO(alexeagle): users will need some control over browser; needs design
_BROWSER = "Chrome"

def _ts_web_test_impl(ctx):
  conf = ctx.actions.declare_file(
      "%s.conf.js" % ctx.label.name,
      sibling=ctx.outputs.executable)

  files = depset(ctx.files.srcs)
  for d in ctx.attr.deps:
    if hasattr(d, "node_sources"):
      files += d.node_sources
    elif hasattr(d, "files"):
      files += d.files

  # The files in the bootstrap attribute come before the require.js support.
  # Note that due to frameworks = ['jasmine'], a few scripts will come before
  # the bootstrap entries:
  # build_bazel_rules_typescript_karma_deps/node_modules/jasmine-core/lib/jasmine-core/jasmine.js
  # build_bazel_rules_typescript_karma_deps/node_modules/karma-jasmine/lib/boot.js
  # build_bazel_rules_typescript_karma_deps/node_modules/karma-jasmine/lib/adapter.js
  # This is desired so that the bootstrap entries can patch jasmine, as zone.js does.
  files_entries = [
      expand_path_into_runfiles(ctx, f.short_path)
      for f in ctx.files.bootstrap
  ]
  # Explicitly list the requirejs library files here, rather than use
  # `frameworks: ['requirejs']`
  # so that we control the script order, and the bootstrap files come before
  # require.js.
  # That allows bootstrap files to have anonymous AMD modules, or to do some
  # polyfilling before test libraries load.
  # See https://github.com/karma-runner/karma/issues/699
  files_entries += [
    "build_bazel_rules_typescript_karma_deps/node_modules/requirejs/require.js",
    "build_bazel_rules_typescript_karma_deps/node_modules/karma-requirejs/lib/adapter.js",
    "build_bazel_rules_typescript_karma_deps/node_modules/karma/requirejs.config.tpl.js",
  ]
  # Finally we load the user's srcs and deps
  files_entries += [
      expand_path_into_runfiles(ctx, f.short_path)
      for f in files
  ]

  # root-relative (runfiles) path to the directory containing karma.conf
  config_segments = len(conf.short_path.split("/"))

  ctx.actions.expand_template(
      output = conf,
      template =  ctx.file._conf_tmpl,
      substitutions = {
          "TMPL_runfiles_path": "/".join([".."] * config_segments),
          "TMPL_files": "\n".join(["      '%s'," % e for e in files_entries]),
          "TMPL_workspace_name": ctx.workspace_name,
          "TMPL_browser": _BROWSER,
          "TMPL_headlessbrowser": "%sHeadless" % _BROWSER,
      })

  ctx.actions.write(
      output = ctx.outputs.executable,
      is_executable = True,
      content = """#!/usr/bin/env bash
readonly KARMA={TMPL_karma}
readonly CONF={TMPL_conf}
export HOME=$(mktemp -d)
ARGV=( "start" $CONF )

# Detect that we are running as a test, by using a well-known environment
# variable. See go/test-encyclopedia
if [ ! -z "$TEST_TMPDIR" ]; then
  ARGV+=( "--single-run" )
fi

$KARMA ${{ARGV[@]}}
""".format(TMPL_karma = ctx.executable._karma.short_path,
           TMPL_conf = conf.short_path))
  return [DefaultInfo(
      runfiles = ctx.runfiles(
          files = ctx.files.srcs + ctx.files.deps + ctx.files.bootstrap + [
              conf,
          ],
          transitive_files = files,
          # Propagate karma_bin and its runfiles
          collect_data = True,
          collect_default = True,
      ),
  )]

ts_web_test = rule(
    implementation = _ts_web_test_impl,
    test = True,
    attrs = {
        "srcs": attr.label_list(allow_files = ["js"]),
        "deps": attr.label_list(
          allow_files = True,
          aspects = [sources_aspect],
        ),
        "bootstrap": attr.label_list(
            allow_files = True,
        ),
        "data": attr.label_list(cfg = "data"),
        "_karma": attr.label(
            default = Label("//internal/karma:karma_bin"),
            executable = True,
            cfg = "data",
            single_file = False,
            allow_files = True),
        "_conf_tmpl": attr.label(
            default = Label(_CONF_TMPL),
            allow_files = True, single_file = True),
    },
)

# This macro exists only to modify the users rule definition a bit.
# DO NOT add composition of additional rules here.
def ts_web_test_macro(tags = [], data = [], **kwargs):
  ts_web_test(
      tags = tags + [
          # Users don't need to know that this tag is required to run under ibazel
          "ibazel_notify_changes",
          # Always attach this label to allow filtering, eg. envs w/ no browser
          "browser:%s" % _BROWSER,
      ],
      # Our binary dependency must be in data[] for collect_data to pick it up
      # FIXME: maybe we can just ask the attr._karma for its runfiles attr
      data = data + ["@build_bazel_rules_typescript//internal/karma:karma_bin"],
      **kwargs)