# -*- coding: utf-8 -*-
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

from __future__ import absolute_import, print_function, unicode_literals

import logging
import re
import os

import attr
import six

from .. import GECKO
from .treeherder import join_symbol
from taskgraph.util.attributes import match_run_on_projects, RELEASE_PROJECTS

from taskgraph.util.attributes import ALL_PROJECTS, RUN_ON_PROJECT_ALIASES

logger = logging.getLogger(__name__)
doc_base_path = os.path.join(GECKO, "taskcluster", "docs")


@attr.s(frozen=True)
class Verification(object):
    verify = attr.ib()
    run_on_projects = attr.ib()


@attr.s(frozen=True)
class VerificationSequence(object):
    """
    Container for a sequence of verifications over a TaskGraph. Each
    verification is represented as a callable taking (task, taskgraph,
    scratch_pad), called for each task in the taskgraph, and one more
    time with no task but with the taskgraph and the same scratch_pad
    that was passed for each task.
    """

    _verifications = attr.ib(factory=dict)

    def __call__(self, graph_name, graph, graph_config, parameters):
        for verification in self._verifications.get(graph_name, []):
            if not match_run_on_projects(
                parameters["project"], verification.run_on_projects
            ):
                continue
            scratch_pad = {}
            graph.for_each_task(
                verification.verify,
                scratch_pad=scratch_pad,
                graph_config=graph_config,
                parameters=parameters,
            )
            verification.verify(
                None,
                graph,
                scratch_pad=scratch_pad,
                graph_config=graph_config,
                parameters=parameters,
            )
        return graph_name, graph

    def add(self, graph_name, run_on_projects={"all"}):
        def wrap(func):
            self._verifications.setdefault(graph_name, []).append(
                Verification(func, run_on_projects)
            )
            return func

        return wrap


verifications = VerificationSequence()


@attr.s(frozen=True)
class DocPaths(object):
    _paths = attr.ib(factory=list)

    def get_files(self, filename):
        rv = []
        for p in self._paths:
            doc_path = os.path.join(p, filename)
            if os.path.exists(doc_path):
                rv.append(doc_path)
        return rv

    def add(self, path):
        """
        Projects that make use of Firefox's taskgraph can extend it with
        their own task kinds by registering additional paths for documentation.
        documentation_paths.add() needs to be called by the project's Taskgraph
        registration function. See taskgraph.config.
        """
        self._paths.append(path)


documentation_paths = DocPaths()
documentation_paths.add(doc_base_path)


def verify_docs(filename, identifiers, appearing_as):
    """
    Look for identifiers of the type appearing_as in the files
    returned by documentation_paths.get_files(). Firefox will have
    a single file in a list, but projects such as Thunderbird can have
    documentation in another location and may return multiple files.
    """
    # We ignore identifiers starting with '_' for the sake of tests.
    # Strings starting with "_" are ignored for doc verification
    # hence they can be used for faking test values
    doc_files = documentation_paths.get_files(filename)
    doctext = "".join([open(d).read() for d in doc_files])

    if appearing_as == "inline-literal":
        expression_list = [
            "``" + identifier + "``"
            for identifier in identifiers
            if not identifier.startswith("_")
        ]
    elif appearing_as == "heading":
        expression_list = [
            "\n" + identifier + "\n(?:(?:(?:-+\n)+)|(?:(?:.+\n)+))"
            for identifier in identifiers
            if not identifier.startswith("_")
        ]
    else:
        raise Exception("appearing_as = `{}` not defined".format(appearing_as))

    for expression, identifier in zip(expression_list, identifiers):
        match_group = re.search(expression, doctext)
        if not match_group:
            raise Exception(
                "{}: `{}` missing from doc file: `{}`".format(
                    appearing_as, identifier, filename
                )
            )


@verifications.add("full_task_graph")
def verify_task_graph_symbol(task, taskgraph, scratch_pad, graph_config, parameters):
    """
    This function verifies that tuple
    (collection.keys(), machine.platform, groupSymbol, symbol) is unique
    for a target task graph.
    """
    if task is None:
        return
    task_dict = task.task
    if "extra" in task_dict:
        extra = task_dict["extra"]
        if "treeherder" in extra:
            treeherder = extra["treeherder"]

            collection_keys = tuple(sorted(treeherder.get("collection", {}).keys()))
            if len(collection_keys) != 1:
                raise Exception(
                    "Task {} can't be in multiple treeherder collections "
                    "(the part of the platform after `/`): {}".format(
                        task.label, collection_keys
                    )
                )
            platform = treeherder.get("machine", {}).get("platform")
            group_symbol = treeherder.get("groupSymbol")
            symbol = treeherder.get("symbol")

            key = (platform, collection_keys[0], group_symbol, symbol)
            if key in scratch_pad:
                raise Exception(
                    "Duplicate treeherder platform and symbol in tasks "
                    "`{}`and `{}`: {} {}".format(
                        task.label,
                        scratch_pad[key],
                        "{}/{}".format(platform, collection_keys[0]),
                        join_symbol(group_symbol, symbol),
                    )
                )
            else:
                scratch_pad[key] = task.label


@verifications.add("full_task_graph")
def verify_trust_domain_v2_routes(
    task, taskgraph, scratch_pad, graph_config, parameters
):
    """
    This function ensures that any two tasks have distinct ``index.{trust-domain}.v2`` routes.
    """
    if task is None:
        return
    route_prefix = "index.{}.v2".format(graph_config["trust-domain"])
    task_dict = task.task
    routes = task_dict.get("routes", [])

    for route in routes:
        if route.startswith(route_prefix):
            if route in scratch_pad:
                raise Exception(
                    "conflict between {}:{} for route: {}".format(
                        task.label, scratch_pad[route], route
                    )
                )
            else:
                scratch_pad[route] = task.label


@verifications.add("full_task_graph")
def verify_routes_notification_filters(
    task, taskgraph, scratch_pad, graph_config, parameters
):
    """
    This function ensures that only understood filters for notifications are
    specified.

    See: https://firefox-ci-tc.services.mozilla.com/docs/manual/using/task-notifications
    """
    if task is None:
        return
    route_prefix = "notify."
    valid_filters = ("on-any", "on-completed", "on-failed", "on-exception")
    task_dict = task.task
    routes = task_dict.get("routes", [])

    for route in routes:
        if route.startswith(route_prefix):
            # Get the filter of the route
            route_filter = route.split(".")[-1]
            if route_filter not in valid_filters:
                raise Exception(
                    "{} has invalid notification filter ({})".format(
                        task.label, route_filter
                    )
                )


@verifications.add("full_task_graph")
def verify_dependency_tiers(task, taskgraph, scratch_pad, graph_config, parameters):
    tiers = scratch_pad
    if task is not None:
        tiers[task.label] = (
            task.task.get("extra", {}).get("treeherder", {}).get("tier", six.MAXSIZE)
        )
    else:

        def printable_tier(tier):
            if tier == six.MAXSIZE:
                return "unknown"
            return tier

        for task in six.itervalues(taskgraph.tasks):
            tier = tiers[task.label]
            for d in six.itervalues(task.dependencies):
                if taskgraph[d].task.get("workerType") == "always-optimized":
                    continue
                if "dummy" in taskgraph[d].kind:
                    continue
                if tier < tiers[d]:
                    raise Exception(
                        "{} (tier {}) cannot depend on {} (tier {})".format(
                            task.label,
                            printable_tier(tier),
                            d,
                            printable_tier(tiers[d]),
                        )
                    )


@verifications.add("full_task_graph")
def verify_required_signoffs(task, taskgraph, scratch_pad, graph_config, parameters):
    """
    Task with required signoffs can't be dependencies of tasks with less
    required signoffs.
    """
    all_required_signoffs = scratch_pad
    if task is not None:
        all_required_signoffs[task.label] = set(
            task.attributes.get("required_signoffs", [])
        )
    else:

        def printable_signoff(signoffs):
            if len(signoffs) == 1:
                return "required signoff {}".format(*signoffs)
            elif signoffs:
                return "required signoffs {}".format(", ".join(signoffs))
            else:
                return "no required signoffs"

        for task in six.itervalues(taskgraph.tasks):
            required_signoffs = all_required_signoffs[task.label]
            for d in six.itervalues(task.dependencies):
                if required_signoffs < all_required_signoffs[d]:
                    raise Exception(
                        "{} ({}) cannot depend on {} ({})".format(
                            task.label,
                            printable_signoff(required_signoffs),
                            d,
                            printable_signoff(all_required_signoffs[d]),
                        )
                    )


@verifications.add("full_task_graph")
def verify_toolchain_alias(task, taskgraph, scratch_pad, graph_config, parameters):
    """
    This function verifies that toolchain aliases are not reused.
    """
    if task is None:
        return
    attributes = task.attributes
    if "toolchain-alias" in attributes:
        key = attributes["toolchain-alias"]
        if key in scratch_pad:
            raise Exception(
                "Duplicate toolchain-alias in tasks "
                "`{}`and `{}`: {}".format(
                    task.label,
                    scratch_pad[key],
                    key,
                )
            )
        else:
            scratch_pad[key] = task.label


@verifications.add("optimized_task_graph")
def verify_always_optimized(task, taskgraph, scratch_pad, graph_config, parameters):
    """
    This function ensures that always-optimized tasks have been optimized.
    """
    if task is None:
        return
    if task.task.get("workerType") == "always-optimized":
        raise Exception("Could not optimize the task {!r}".format(task.label))


@verifications.add("full_task_graph", run_on_projects=RELEASE_PROJECTS)
def verify_shippable_no_sccache(task, taskgraph, scratch_pad, graph_config, parameters):
    if task and task.attributes.get("shippable"):
        if task.task.get("payload", {}).get("env", {}).get("USE_SCCACHE"):
            raise Exception("Shippable job {} cannot use sccache".format(task.label))


@verifications.add("full_task_graph")
def verify_test_packaging(task, taskgraph, scratch_pad, graph_config, parameters):
    if task is None:
        # In certain cases there are valid reasons for tests to be missing,
        # don't error out when that happens.
        missing_tests_allowed = any(
            (
                # user specified `--target-kind`
                parameters.get("target-kind") is not None,
                # manifest scheduling is enabled
                parameters["test_manifest_loader"] != "default",
            )
        )

        exceptions = []
        for task in six.itervalues(taskgraph.tasks):
            if task.kind == "build" and not task.attributes.get(
                "skip-verify-test-packaging"
            ):
                build_env = task.task.get("payload", {}).get("env", {})
                package_tests = build_env.get("MOZ_AUTOMATION_PACKAGE_TESTS")
                shippable = task.attributes.get("shippable", False)
                build_has_tests = scratch_pad.get(task.label)

                if package_tests != "1":
                    # Shippable builds should always package tests.
                    if shippable:
                        exceptions.append(
                            "Build job {} is shippable and does not specify "
                            "MOZ_AUTOMATION_PACKAGE_TESTS=1 in the "
                            "environment.".format(task.label)
                        )

                    # Build tasks in the scratch pad have tests dependent on
                    # them, so we need to package tests during build.
                    if build_has_tests:
                        exceptions.append(
                            "Build job {} has tests dependent on it and does not specify "
                            "MOZ_AUTOMATION_PACKAGE_TESTS=1 in the environment".format(
                                task.label
                            )
                        )
                else:
                    # Build tasks that aren't in the scratch pad have no
                    # dependent tests, so we shouldn't package tests.
                    # With the caveat that we expect shippable jobs to always
                    # produce tests.
                    if not build_has_tests and not shippable:
                        # If we have not generated all task kinds, we can't verify that
                        # there are no dependent tests.
                        if not missing_tests_allowed:
                            exceptions.append(
                                "Build job {} has no tests, but specifies "
                                "MOZ_AUTOMATION_PACKAGE_TESTS={} in the environment. "
                                "Unset MOZ_AUTOMATION_PACKAGE_TESTS in the task definition "
                                "to fix.".format(task.label, package_tests)
                            )
        if exceptions:
            raise Exception("\n".join(exceptions))
        return
    if task.kind == "test":
        build_task = taskgraph[task.dependencies["build"]]
        scratch_pad[build_task.label] = 1


@verifications.add("full_task_graph")
def verify_run_known_projects(task, taskgraph, scratch_pad, graph_config, parameters):
    """Validates the inputs in run-on-projects.

    We should never let 'try' (or 'try-comm-central') be in run-on-projects even though it
    is valid because it is not considered for try pushes.  While here we also validate for
    other unknown projects or typos.
    """
    if task and task.attributes.get("run_on_projects"):
        projects = set(task.attributes["run_on_projects"])
        if {"try", "try-comm-central"} & set(projects):
            raise Exception(
                "In task {}: using try in run-on-projects is invalid; use try "
                "selectors to select this task on try".format(task.label)
            )
        # try isn't valid, but by the time we get here its not an available project anyway.
        valid_projects = ALL_PROJECTS | set(RUN_ON_PROJECT_ALIASES.keys())
        invalid_projects = projects - valid_projects
        if invalid_projects:
            raise Exception(
                "Task '{}' has an invalid run-on-projects value: "
                "{}".format(task.label, invalid_projects)
            )


@verifications.add("full_task_graph")
def verify_local_toolchains(task, taskgraph, scratch_pad, graph_config, parameters):
    """
    Toolchains that are used for local development need to be built on a
    level-3 branch to installable via `mach bootstrap`. We ensure here that all
    such tasks run on at least trunk projects, even if they aren't pulled in as
    a dependency of other tasks in the graph.

    There is code in `mach artifact toolchain` that verifies that anything
    installed via `mach bootstrap` has the attribute set.
    """
    if task and task.attributes.get("local-toolchain"):
        run_on_projects = task.attributes.get("run_on_projects", [])
        if not any(alias in run_on_projects for alias in ["all", "trunk"]):
            raise Exception(
                "Toolchain {} used for local development is not built on trunk. {}".format(
                    task.label, run_on_projects
                )
            )