from datetime import datetime
from io import BytesIO
from itertools import groupby
from operator import attrgetter
from typing import Union

import structlog
from django.http import HttpResponse
from openpyxl import Workbook

from vbv_lernwelt.core.models import User
from vbv_lernwelt.course.models import CourseCompletionStatus, CourseSession
from vbv_lernwelt.course.services import mark_course_completion
from vbv_lernwelt.feedback.models import FeedbackResponse
from vbv_lernwelt.learnpath.models import (
    LearningContentFeedbackUK,
    LearningContentFeedbackVV,
)

logger = structlog.get_logger(__name__)

VV_FEEDBACK_QUESTIONS = [
    ("satisfaction", "Zufriedenheit insgesamt"),
    ("goal_attainment", "Zielerreichung insgesamt"),
    (
        "proficiency",
        "Wie beurteilst du deine Sicherheit bezüglichen den Themen nach dem Circle?",
    ),
    ("preparation_task_clarity", "Waren die Praxisaufträge klar und verständlich?"),
    ("would_recommend", "Würdest du den Circle weiterempfehlen?"),
    ("course_positive_feedback", "Was hat dir besonders gut gefallen?"),
    ("course_negative_feedback", "Wo siehst du Verbesserungspotential?"),
]

UK_FEEDBACK_QUESTIONS = [
    ("satisfaction", "Zufriedenheit insgesamt"),
    ("goal_attainment", "Zielerreichung insgesamt"),
    (
        "proficiency",
        "Wie beurteilst du deine Sicherheit bezüglichen den Themen nach dem Kurs?",
    ),
    (
        "preparation_task_clarity",
        "Waren die Vorbereitungsaufträge klar und verständlich?",
    ),
    (
        "instructor_competence",
        "Wie beurteilst du die Themensicherheit und Fachkompetenz des Kursleiters/der Kursleiterin?",
    ),
    (
        "instructor_respect",
        "Wurden Fragen und Anregungen der Kursteilnehmenden ernst genommen und aufgegriffen?",
    ),
    (
        "instructor_open_feedback",
        "Was möchtest du dem Kursleiter/der Kursleiterin sonst noch sagen?",
    ),
    ("would_recommend", "Würdest du den Kurs weiterempfehlen?"),
    ("course_positive_feedback", "Was hat dir besonders gut gefallen?"),
    ("course_negative_feedback", "Wo siehst du Verbesserungspotential?"),
]


def update_feedback_response(
    feedback_user: User,
    course_session: CourseSession,
    learning_content_feedback_page: Union[
        LearningContentFeedbackUK, LearningContentFeedbackVV
    ],
    submitted: bool,
    validated_data: dict,
):
    circle = learning_content_feedback_page.get_circle()

    feedback_response, _ = FeedbackResponse.objects.get_or_create(
        feedback_user_id=feedback_user.id,
        circle_id=circle.id,
        course_session=course_session,
    )

    original_data = feedback_response.data
    updated_data = validated_data
    initial_data = initial_data_for_feedback_page(learning_content_feedback_page)

    merged_data = initial_data | {
        key: updated_data[key]
        if updated_data.get(key, "") != ""
        else original_data.get(key)
        for key in initial_data.keys()
    }

    feedback_response.data = merged_data

    # save the response before completion mark,
    # because who knows what could happen in between...
    if submitted:
        feedback_response.submitted = submitted
    feedback_response.save()

    if submitted:
        mark_course_completion(
            user=feedback_user,
            page=learning_content_feedback_page,
            course_session=course_session,
            completion_status=CourseCompletionStatus.SUCCESS.value,
        )

    logger.info(
        "feedback successfully created",
        label="feedback",
        feedback_user_id=feedback_user.id,
        circle_title=circle.title,
        course_session_id=course_session.id,
    )

    return feedback_response


def initial_data_for_feedback_page(
    learning_content_feedback_page: Union[
        LearningContentFeedbackUK, LearningContentFeedbackVV
    ]
):
    if hasattr(learning_content_feedback_page, "learningcontentfeedbackuk"):
        return {
            "satisfaction": None,
            "goal_attainment": None,
            "proficiency": None,
            "preparation_task_clarity": None,
            "instructor_competence": None,
            "instructor_respect": None,
            "instructor_open_feedback": "",
            "would_recommend": None,
            "course_negative_feedback": "",
            "course_positive_feedback": "",
            "feedback_type": "uk",
        }
    if hasattr(learning_content_feedback_page, "learningcontentfeedbackvv"):
        return {
            "satisfaction": None,
            "goal_attainment": None,
            "proficiency": None,
            "preparation_task_clarity": None,
            "would_recommend": None,
            "course_negative_feedback": "",
            "course_positive_feedback": "",
            "feedback_type": "vv",
        }
    return {}


def export_feedback(course_session_ids: list[str], save_as_file: bool):
    wb = Workbook()

    # remove the first sheet is just easier than keeping track of the active sheet
    wb.remove_sheet(wb.active)

    feedbacks = FeedbackResponse.objects.filter(
        course_session_id__in=course_session_ids,
        submitted=True,
    ).order_by("circle", "course_session", "updated_at")
    grouped_feedbacks = groupby(feedbacks, key=attrgetter("circle"))

    for circle, group_feedbacks in grouped_feedbacks:
        group_feedbacks = list(group_feedbacks)
        logger.debug(
            "export_feedback_for_circle",
            data={
                "circle": circle.id,
                "course_session_ids": course_session_ids,
                "count": len(group_feedbacks),
            },
            label="feedback_export",
        )
        _create_sheet(wb, circle.title, group_feedbacks)

    if save_as_file:
        wb.save(make_export_filename())
    else:
        output = BytesIO()
        wb.save(output)

        output.seek(0)
        return output.getvalue()


def _create_sheet(wb: Workbook, title: str, data: list[FeedbackResponse]):
    sheet = wb.create_sheet(title=_sanitize_sheet_name(title))

    if len(data) == 0:
        return sheet

    # we instruct the users not to mix exports of different courses, so we can assume the questions are the same and of the first type
    question_data = (
        UK_FEEDBACK_QUESTIONS
        if data[0].data["feedback_type"] == "uk"
        else VV_FEEDBACK_QUESTIONS
    )

    # add header
    sheet.cell(row=1, column=1, value="Durchführung")
    sheet.cell(row=1, column=2, value="Datum")
    questions = [q[1] for q in question_data]
    for col_idx, title in enumerate(questions, start=3):
        sheet.cell(row=1, column=col_idx, value=title)

    _add_rows(sheet, data, question_data)
    return sheet


def _sanitize_sheet_name(text, default_name="DefaultSheet"):
    if text is None:
        return default_name

    prohibited_chars = ["\\", "/", "*", "?", ":", "[", "]"]
    for char in prohibited_chars:
        text = text.replace(char, "")

    text = text.strip("'")

    text = text[:31]

    if len(text) == 0:
        return default_name

    return text


def _add_rows(sheet, data, question_data):
    for row_idx, feedback in enumerate(data, start=2):
        sheet.cell(row=row_idx, column=1, value=feedback.course_session.title)
        sheet.cell(
            row=row_idx, column=2, value=feedback.updated_at.date().strftime("%d.%m.%Y")
        )
        for col_idx, question in enumerate(question_data, start=3):
            response = feedback.data.get(question[0], "")
            sheet.cell(row=row_idx, column=col_idx, value=response)


def make_export_filename(name: str = "feedback_export"):
    today_date = datetime.today().strftime("%Y-%m-%d")
    return f"{name}_{today_date}.xlsx"


# used as admin action, that's why it's not in the views.py
def get_feedbacks_for_course_sessions(_modeladmin, _request, queryset):
    file_name = "feedback_export_durchfuehrungen"
    return _handle_feedback_export_action(queryset, file_name)


def get_feedbacks_for_courses(_modeladmin, _request, queryset):
    course_sessions = CourseSession.objects.filter(course__in=queryset)
    file_name = "feedback_export_lehrgaenge"
    return _handle_feedback_export_action(course_sessions, file_name)


def _handle_feedback_export_action(course_seesions, file_name):
    excel_bytes = export_feedback(course_seesions, False)

    response = HttpResponse(
        content_type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
    )
    response[
        "Content-Disposition"
    ] = f"attachment; filename={make_export_filename(file_name)}"
    response.write(excel_bytes)

    return response