# Copyright 2015: Mirantis Inc.
# 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.

import copy
from docutils.parsers import rst
import json
import re

from . import utils
from rally.common.plugin import discover
from rally.common.plugin import plugin
from rally.common import validation
from rally import plugins


JSON_SCHEMA_TYPES_MAP = {"boolean": "bool",
                         "string": "str",
                         "number": "float",
                         "integer": "int",
                         "array": "list",
                         "object": "dict"}


def process_jsonschema(schema):
    """Process jsonschema and make it looks like regular docstring."""

    if not schema:
        # nothing to parse
        return

    if "type" in schema:

        # str
        if schema["type"] == "string":
            doc = schema.get("description", "")
            if "pattern" in schema:
                doc += ("\n\nShould follow next pattern: %s." %
                        schema["pattern"])
            return {"doc": doc, "type": "str"}

        # int or float
        elif schema["type"] in ("integer", "number"):
            doc = schema.get("description", "")
            if "minimum" in schema:
                doc += "\n\nMin value: %s." % schema["minimum"]
            if "maximum" in schema:
                doc += "\n\nMax value: %s." % schema["maximum"]
            return {"doc": doc, "type": JSON_SCHEMA_TYPES_MAP[schema["type"]]}

        # bool or null
        elif schema["type"] in ("boolean", "null"):
            return {"doc": schema.get("description", ""),
                    "type": "bool" if schema["type"] == "boolean" else "null"}

        # list
        elif schema["type"] == "array":
            info = {"doc": schema.get("description", ""),
                    "type": "list"}

            if "items" in schema:
                if info["doc"]:
                    info["doc"] += "\n\n"
                info["doc"] += ("Elements of the list should follow format(s) "
                                "described below:\n\n")

                items = schema["items"]
                itype = None
                if "type" in items:
                    itype = JSON_SCHEMA_TYPES_MAP.get(items["type"],
                                                      items["type"])
                    info["doc"] += "- Type: %s. " % itype
                if "description" in items:
                    # add indention
                    desc = items["description"].split("\n")
                    info["doc"] += "\n  ".join(desc)

                new_schema = copy.copy(items)
                new_schema.pop("description", None)
                new_schema = json.dumps(new_schema, indent=4)
                new_schema = "\n     ".join(
                    new_schema.split("\n"))

                info["doc"] += ("\n  Format:\n\n"
                                "    .. code-block:: json\n\n"
                                "      %s\n" % new_schema)
            return info

        elif isinstance(schema["type"], list):
            # it can be too complicated for parsing... do not do it deeply
            return {"doc": schema.get("description", ""),
                    "type": "/".join(schema["type"])}

        # dict
        elif schema["type"] == "object":
            info = {"doc": schema.get("description", ""),
                    "type": "dict",
                    "parameters": []}
            required_parameters = schema.get("required", [])
            if "properties" in schema:
                for name in schema["properties"]:
                    if isinstance(schema["properties"][name], str):
                        pinfo = {"name": name,
                                 "type": schema["properties"][name],
                                 "doc": ""}
                    else:
                        pinfo = process_jsonschema(schema["properties"][name])
                        if name in required_parameters:
                            pinfo["required"] = True
                        pinfo["name"] = name
                    info["parameters"].append(pinfo)
            elif "patternProperties" in schema:
                info.pop("parameters", None)
                info["patternProperties"] = []
                for k, v in schema["patternProperties"].items():
                    info["patternProperties"].append(process_jsonschema(v))
                    info["patternProperties"][-1]["name"] = k
                    info["patternProperties"][-1]["type"] = "str"
            elif (not (set(schema.keys()) - {"type", "description", "$schema",
                                             "additionalProperties"})):
                # it is ok, schema accepts any object. nothing to add more
                pass
            elif "oneOf" in schema or "anyOf" in schema:
                # Example:
                #   SCHEMA = {"type": "object", "$schema": consts.JSON_SCHEMA,
                #       "oneOf": [{"properties": {"foo": {"type": "string"}}
                #                  "required": ["foo"],
                #                  "additionalProperties": False},
                #                 {"properties": {"bar": {"type": "string"}}
                #                  "required": ["bar"],
                #                  "additionalProperties": False},
                #
                schema_key = "oneOf" if "oneOf" in schema else "anyOf"
                schema_value = copy.deepcopy(schema.get(schema_key))

                for item in schema_value:
                    for k, v in schema.items():
                        if k not in (schema_key, "description"):
                            item[k] = v

                return {
                    "doc": schema.get("description", ""),
                    "type": "dict",
                    schema_key: [
                        process_jsonschema(item) for item in schema_value]
                }
            else:
                raise Exception("Failed to parse jsonschema: %s" % schema)

            if "definitions" in schema:
                info["definitions"] = schema["definitions"]
            return info
        else:
            raise Exception("Failed to parse jsonschema: %s" % schema)

    # enum
    elif "enum" in schema:
        doc = schema.get("description", "")
        doc += "\nSet of expected values: '%s'." % ("', '".join(
            [e or "None" for e in schema["enum"]]))
        return {"doc": doc}

    elif "anyOf" in schema:
        return {"doc": schema.get("description", ""),
                "anyOf": [process_jsonschema(i) for i in schema["anyOf"]]}

    elif "oneOf" in schema:
        return {"doc": schema.get("description", ""),
                "oneOf": [process_jsonschema(i) for i in schema["oneOf"]]}

    elif "$ref" in schema:
        return {"doc": schema.get("description", "n/a"),
                "ref": schema["$ref"]}
    else:
        raise Exception("Failed to parse jsonschema: %s" % schema)


CATEGORIES = {
    "Common": ["OS Client"],
    "Deployment": ["Engine", "Provider Factory"],
    "Task Component": ["Chart", "Context", "Hook Action", "Hook Trigger",
                       "Resource Type", "Task Exporter", "SLA", "Scenario",
                       "Scenario Runner", "Trigger", "Validator"],
    "Verification Component": ["Verifier Context", "Verification Reporter",
                               "Verifier Manager"]
}

# NOTE(andreykurilin): several bases do not have docstings at all, so it is
# redundant to display them
IGNORED_BASES = ["Resource Type", "OS Client", "Exporters"]


class PluginsReferenceDirective(rst.Directive):
    optional_arguments = 1
    option_spec = {"base_cls": str}

    def _make_arg_items(self, items, ref_prefix, description=None,
                        title="Parameters"):
        terms = []
        for item in items:
            iname = item.get("name", "") or item.pop("type")
            if "type" in item:
                iname += " (%s)" % item["type"]
            terms.append((iname, [item["doc"]]))
        return utils.make_definitions(title=title,
                                      ref_prefix=ref_prefix,
                                      terms=terms,
                                      descriptions=description)

    def _make_plugin_section(self, plugin_cls, base_name=None):
        section_name = plugin_cls.get_name()
        if base_name:
            section_name += " [%s]" % base_name
        section_obj = utils.section(section_name)

        info = plugin_cls.get_info()
        if info["title"]:
            section_obj.append(utils.paragraph(info["title"]))

        if info["description"]:
            section_obj.extend(utils.parse_text(info["description"]))

        if info["platform"]:
            section_obj.append(utils.paragraph(
                "**Platform**: %s" % info["platform"]))

        if base_name:
            ref_prefix = "%s-%s-" % (base_name, plugin_cls.get_name())
        else:
            ref_prefix = "%s-" % plugin_cls.get_name()

        if info["parameters"]:
            section_obj.extend(self._make_arg_items(info["parameters"],
                                                    ref_prefix))

        if info["returns"]:
            section_obj.extend(utils.parse_text(
                "**Returns**:\n%s" % info["returns"]))

        if info["schema"]:
            schema = process_jsonschema(info["schema"])
            if "type" in schema:
                if "parameters" in schema:
                    section_obj.extend(self._make_arg_items(
                        items=schema["parameters"],
                        ref_prefix=ref_prefix))
                elif "patternProperties" in schema:
                    section_obj.extend(self._make_arg_items(
                        items=schema["patternProperties"],
                        ref_prefix=ref_prefix,
                        description=["*Dictionary is expected. Keys should "
                                     "follow pattern(s) described bellow.*"]))
                elif "oneOf" in schema:
                    section_obj.append(utils.note(
                        "One of the following groups of "
                        "parameters should be provided."))
                    for i, oneOf in enumerate(schema["oneOf"], 1):
                        description = None
                        if oneOf.get("doc", None):
                            description = [oneOf["doc"]]
                        section_obj.extend(self._make_arg_items(
                            items=oneOf["parameters"],
                            ref_prefix=ref_prefix,
                            title="Option %s of parameters" % i,
                            description=description))
                else:
                    section_obj.extend(self._make_arg_items(
                        items=[schema], ref_prefix=ref_prefix))
            else:
                raise Exception("Failed to display provided schema: %s" %
                                info["schema"])

        if issubclass(plugin_cls, validation.ValidatablePluginMixin):
            validators = plugin_cls._meta_get("validators", default=[])
            platforms = [kwargs for name, args, kwargs in validators
                         if name == "required_platform"]
            if platforms:
                section_obj.append(
                    utils.paragraph("**Requires platform(s)**:"))
                section = ""
                for p in platforms:
                    section += "* %s" % p["platform"]
                    admin_msg = "credentials for admin user"
                    user_msg = ("regular users (temporary users can be created"
                                " via the 'users' context if admin user is "
                                "specified for the platform)")
                    if p.get("admin", False) and p.get("users", False):
                        section += " with %s and %s." % (admin_msg, user_msg)
                    elif p.get("admin", False):
                        section += " with %s." % admin_msg
                    elif p.get("users", False):
                        section += " with %s." % user_msg
                    section += "\n"

                section_obj.extend(utils.parse_text(section))

        filename = info["module"].replace(".", "/")
        if filename.startswith("rally/"):
            project = "rally"
        elif filename.startswith("rally_openstack/"):
            project = "rally-openstack"
        else:
            # WTF is it?!
            return None
        ref = ("https://github.com/openstack/%s/blob/master/%s.py"
               % (project, filename))
        section_obj.extend(utils.parse_text("**Module**:\n`%s`__\n\n__ %s"
                           % (info["module"], ref)))
        return section_obj

    def _make_plugin_base_section(self, base_cls, base_name=None):
        if base_name:
            title = ("%ss" % base_name if base_name[-1] != "y"
                     else "%sies" % base_name[:-1])
            subcategory_obj = utils.subcategory(title)
        else:
            subcategory_obj = []
        for p in sorted(base_cls.get_all(), key=lambda o: o.get_name()):
            # do not display hidden contexts
            if p._meta_get("hidden", False):
                continue
            subcategory_obj.append(self._make_plugin_section(p, base_name))

        return subcategory_obj

    @staticmethod
    def _parse_class_name(cls):
        name = ""
        for word in re.split(r"([A-Z][a-z]*)", cls.__name__):
            if word:
                if len(word) > 1 and name:
                    name += " "
                name += word
        return name

    @plugins.ensure_plugins_are_loaded
    def _get_all_plugins_bases(self):
        """Return grouped and sorted all plugins bases."""
        bases = []
        bases_names = []
        for p in discover.itersubclasses(plugin.Plugin):
            base_ref = getattr(p, "base_ref", None)
            if base_ref == p:
                name = self._parse_class_name(p)
                if name in bases_names:
                    raise Exception("Two base classes with same name '%s' are "
                                    "detected." % name)
                bases_names.append(name)
                category_of_base = "Common"
                for cname, cbases in CATEGORIES.items():
                    if name in cbases:
                        category_of_base = cname

                bases.append((category_of_base, name, p))
        return sorted(bases)

    def run(self):
        bases = self._get_all_plugins_bases()
        if "base_cls" in self.options:
            for _category_name, base_name, base_cls in bases:
                if base_name == self.options["base_cls"]:
                    return self._make_plugin_base_section(base_cls)
            raise Exception("Failed to generate plugins reference for '%s'"
                            " plugin base." % self.options["base_cls"])

        categories = {}

        for category_name, base_name, base_cls in bases:
            # FIXME(andreykurilin): do not ignore anything
            if base_name in IGNORED_BASES:
                continue
            if category_name not in categories:
                categories[category_name] = utils.category(category_name)
            category_of_base = categories[category_name]
            category_of_base.append(self._make_plugin_base_section(base_cls,
                                                                   base_name))
        return [content for _name, content in sorted(categories.items())]


def setup(app):
    plugins.load()
    app.add_directive("generate_plugin_reference", PluginsReferenceDirective)