#  IRIS Source Code
#  contact@dfir-iris.org
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU Lesser General Public
#  License as published by the Free Software Foundation; either
#  version 3 of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
#  Lesser General Public License for more details.
#
#  You should have received a copy of the GNU Lesser General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
import marshmallow
from datetime import datetime
from typing import List, Optional, Union

from app import db
from app.datamgmt.case.case_tasks_db import add_task
from app.datamgmt.manage.manage_case_classifications_db import get_case_classification_by_name
from app.iris_engine.module_handler.module_handler import call_modules_hook
from app.models.cases import Cases
from app.models.models import CaseTemplate
from app.models.models import Tags
from app.models.models import NoteDirectory
from app.models.authorization import User
from app.schema.marshables import CaseSchema
from app.schema.marshables import CaseTaskSchema
from app.schema.marshables import CaseNoteDirectorySchema
from app.schema.marshables import CaseNoteSchema


def get_case_templates_list() -> List[dict]:
    """Get a list of case templates

    Returns:
        List[dict]: List of case templates
    """
    case_templates = CaseTemplate.query.with_entities(
        CaseTemplate.id,
        CaseTemplate.name,
        CaseTemplate.display_name,
        CaseTemplate.description,
        CaseTemplate.title_prefix,
        CaseTemplate.author,
        CaseTemplate.created_at,
        CaseTemplate.classification,
        CaseTemplate.updated_at,
        User.name.label('added_by')
    ).join(
        CaseTemplate.created_by_user
    ).all()

    c_cl = [row._asdict() for row in case_templates]
    return c_cl


def get_case_template_by_id(cur_id: int) -> CaseTemplate:
    """Get a case template

    Args:
        cur_id (int): case template id

    Returns:
        CaseTemplate: Case template
    """
    case_template = CaseTemplate.query.filter_by(id=cur_id).first()
    return case_template


def delete_case_template_by_id(case_template_id: int):
    """Delete a case template

    Args:
        case_template_id (int): case template id
    """
    CaseTemplate.query.filter_by(id=case_template_id).delete()


def validate_case_template(data: dict, update: bool = False) -> Optional[str]:
    try:
        if not update:
            # If it's not an update, we check the required fields
            if "name" not in data:
                return "Name is required."

            if "display_name" not in data or not data["display_name"].strip():
                data["display_name"] = data["name"]
        # We check that name is not empty
        if "name" in data and not data["name"].strip():
            return "Name cannot be empty."

        # We check that author length is not above 128 chars
        if "author" in data and len(data["author"]) > 128:
            return "Author cannot be longer than 128 characters."

        # We check that author length is not above 128 chars
        if "author" in data and len(data["author"]) > 128:
            return "Author cannot be longer than 128 characters."

        # We check that prefix length is not above 32 chars
        if "title_prefix" in data and len(data["title_prefix"]) > 32:
            return "Prefix cannot be longer than 32 characters."

        # We check that tags, if any, are a list of strings
        if "tags" in data:
            if not isinstance(data["tags"], list):
                return "Tags must be a list."
            for tag in data["tags"]:
                if not isinstance(tag, str):
                    return "Each tag must be a string."

        # We check that tasks, if any, are a list of dictionaries with mandatory keys
        if "tasks" in data:
            if not isinstance(data["tasks"], list):
                return "Tasks must be a list."
            for task in data["tasks"]:
                if not isinstance(task, dict):
                    return "Each task must be a dictionary."
                if "title" not in task:
                    return "Each task must have a 'title' field."
                if "tags" in task:
                    if not isinstance(task["tags"], list):
                        return "Task tags must be a list."
                    for tag in task["tags"]:
                        if not isinstance(tag, str):
                            return "Each tag must be a string."

        # We check that note groups, if any, are a list of dictionaries with mandatory keys
        if "note_groups" in data:
            return "Note groups has been replaced by note_directories."

        if "note_directories" in data:
            if not isinstance(data["note_directories"], list):
                return "Note directories must be a list."
            for note_dir in data["note_directories"]:
                if not isinstance(note_dir, dict):
                    return "Each note directory must be a dictionary."
                if "title" not in note_dir:
                    return "Each note directory must have a 'title' field."
                if "notes" in note_dir:
                    if not isinstance(note_dir["notes"], list):
                        return "Notes must be a list."
                    for note in note_dir["notes"]:
                        if not isinstance(note, dict):
                            return "Each note must be a dictionary."
                        if "title" not in note:
                            return "Each note must have a 'title' field."

        # If all checks succeeded, we return None to indicate everything is has been validated
        return None
    except Exception as e:
        return str(e)


def case_template_pre_modifier(case_schema: CaseSchema, case_template_id: str):
    case_template = get_case_template_by_id(int(case_template_id))
    if not case_template:
        return None
    if case_template.title_prefix:
        case_schema.name = case_template.title_prefix + " " + case_schema.name[0]

    case_classification = get_case_classification_by_name(case_template.classification)
    if case_classification:
        case_schema.classification_id = case_classification.id

    return case_schema


def case_template_populate_tasks(case: Cases, case_template: CaseTemplate):
    logs = []
    # Update case tasks
    for task_template in case_template.tasks:
        try:
            # validate before saving
            task_schema = CaseTaskSchema()

            # Remap case task template fields
            # Set status to "To Do" which is ID 1
            mapped_task_template = {
                "task_title": task_template['title'],
                "task_description": task_template['description'] if task_template.get('description') else "",
                "task_tags": ",".join(tag for tag in task_template["tags"]) if task_template.get('tags') else "",
                "task_status_id": 1
            }

            mapped_task_template = call_modules_hook('on_preload_task_create', data=mapped_task_template, caseid=case.case_id)

            task = task_schema.load(mapped_task_template)

            assignee_id_list = []

            ctask = add_task(task=task,
                             assignee_id_list=assignee_id_list,
                             user_id=case.user_id,
                             caseid=case.case_id
                             )

            ctask = call_modules_hook('on_postload_task_create', data=ctask, caseid=case.case_id)

            if not ctask:
                logs.append("Unable to create task for internal reasons")

        except marshmallow.exceptions.ValidationError as e:
            logs.append(e.messages)

    return logs


def case_template_populate_notes(case: Cases, note_dir_template: dict, ng: NoteDirectory):
    logs = []
    if note_dir_template.get("notes"):
        for note_template in note_dir_template["notes"]:
            # validate before saving
            note_schema = CaseNoteSchema()

            mapped_note_template = {
                "directory_id": ng.id,
                "note_title": note_template["title"],
                "note_content": note_template["content"] if note_template.get("content") else ""
            }

            mapped_note_template = call_modules_hook('on_preload_note_create',
                                                     data=mapped_note_template,
                                                     caseid=case.case_id)

            note_schema.verify_directory_id(mapped_note_template, caseid=ng.case_id)
            note = note_schema.load(mapped_note_template)

            note.note_creationdate = datetime.utcnow()
            note.note_lastupdate = datetime.utcnow()
            note.note_user = case.user_id
            note.note_case_id = case.case_id

            db.session.add(note)

            note = call_modules_hook('on_postload_note_create', data=note, caseid=case.case_id)

            if not note:
                logs.append("Unable to add note for internal reasons")
                break
    return logs


def case_template_populate_note_groups(case: Cases, case_template: CaseTemplate):
    logs = []
    # Update case tasks
    if case_template.note_directories:
        case_template.note_directories = case_template.note_directories

    for note_dir_template in case_template.note_directories:
        try:
            # validate before saving
            note_dir_schema = CaseNoteDirectorySchema()

            # Remap case task template fields
            # Set status to "To Do" which is ID 1
            mapped_note_dir_template = {
                "name": note_dir_template['title'],
                "parent_id": None,
                "case_id": case.case_id
            }

            note_dir = note_dir_schema.load(mapped_note_dir_template)
            db.session.add(note_dir)
            db.session.commit()

            if not note_dir:
                logs.append("Unable to add note group for internal reasons")
                break

            logs = case_template_populate_notes(case, note_dir_template, note_dir)

        except marshmallow.exceptions.ValidationError as e:
            logs.append(e.messages)

    return logs


def case_template_post_modifier(case: Cases, case_template_id: Union[str, int]):
    case_template = get_case_template_by_id(int(case_template_id))
    logs = []
    if not case_template:
        logs.append(f"Case template {case_template_id} not found")
        return None, logs

    # Update summary, we want to append in order not to skip the initial case description
    case.description += "\n" + case_template.summary

    # Update case tags
    for tag_str in case_template.tags:
        tag = Tags(tag_title=tag_str)
        tag = tag.save()
        case.tags.append(tag)

    # Update case tasks
    logs = case_template_populate_tasks(case, case_template)
    if logs:
        return case, logs

    # Update case note groups
    logs = case_template_populate_note_groups(case, case_template)
    if logs:
        return case, logs

    db.session.commit()

    return case, logs