from __future__ import annotations

from decimal import Decimal

from flask import Blueprint, current_app, g, render_template, send_from_directory
from flask_login import login_required

from app.models import (
    Account,
    Category,
    CommunityAccount,
    CostParticipant,
    InAppNotification,
    Month,
    to_decimal,
)
from app.utils.users import (
    active_users,
    benefit_scope_label,
    personal_account_names,
    personal_users,
    sync_user_participants,
)

main_bp = Blueprint("main", __name__)


def _community_account_cards(month, previous_month):
    community_accounts = CommunityAccount.query.filter_by(is_active=True).order_by(
        CommunityAccount.sort_order.asc(), CommunityAccount.name.asc()
    ).all()
    current_entry_values = {item.entry_id: to_decimal(item.planned_amount) for item in month.entry_values}
    previous_entry_values = (
        {item.entry_id: to_decimal(item.planned_amount) for item in previous_month.entry_values}
        if previous_month is not None
        else {}
    )
    current_allocations = {
        item.target_account.slug: to_decimal(item.amount)
        for item in month.allocations
        if item.target_account
    }
    previous_allocations = (
        {
            item.target_account.slug: to_decimal(item.amount)
            for item in previous_month.allocations
            if item.target_account
        }
        if previous_month is not None
        else {}
    )
    budget_categories = Category.query.join(Account).filter(
        Category.is_active.is_(True),
        Account.slug == "gemeinschaftskonto",
    ).all()
    cards = []
    for community_account in community_accounts:
        if community_account.account_type == "personal" and community_account.linked_account_slug:
            current_total = current_allocations.get(community_account.linked_account_slug, Decimal("0.00"))
            previous_total = previous_allocations.get(community_account.linked_account_slug, Decimal("0.00"))
            assigned_budget_names = ["Persönliche Auszahlung"]
        else:
            assigned_categories = [
                category for category in budget_categories if category.community_account_id == community_account.id
            ]
            current_total = sum(
                (current_entry_values.get(entry.id, Decimal("0.00")) for category in assigned_categories for entry in category.entries if entry.is_active),
                Decimal("0.00"),
            )
            previous_total = sum(
                (previous_entry_values.get(entry.id, Decimal("0.00")) for category in assigned_categories for entry in category.entries if entry.is_active),
                Decimal("0.00"),
            )
            assigned_budget_names = [category.name for category in assigned_categories]
        delta = current_total - previous_total
        cards.append(
            {
                "community_account": community_account,
                "current_total": current_total,
                "previous_total": previous_total,
                "delta": delta,
                "assigned_budget_names": assigned_budget_names,
                "needs_update": delta != Decimal("0.00"),
                "is_read_only": community_account.account_type == "personal",
            }
        )
    return cards


@main_bp.route("/")
@login_required
def index():
    if sync_user_participants():
        current_app.logger.info("App-Nutzer wurden mit Split-Personen synchronisiert.")
        from app.extensions import db

        db.session.commit()
    month = g.current_month
    summary = current_app.extensions["saldo.month_service"].compute_summary(month)
    previous_month = current_app.extensions["saldo.month_service"].previous_month(month.year, month.month)
    recent_months = Month.query.order_by(Month.year.desc(), Month.month.desc()).limit(6).all()
    notifications = (
        InAppNotification.query.filter_by(is_read=False)
        .order_by(InAppNotification.created_at.desc())
        .limit(5)
        .all()
    )
    community_account_cards = _community_account_cards(month, previous_month)
    shared_account_changes = [
        item for item in community_account_cards if not item["is_read_only"] and item["needs_update"]
    ]
    personal_allocations = {
        item.target_account.slug: to_decimal(item.amount)
        for item in month.allocations
        if item.target_account and item.target_account.slug in {"persoenlich-flo", "persoenlich-desi"}
    }
    internal_participants = {
        participant.linked_user_id: participant
        for participant in CostParticipant.query.filter(
            CostParticipant.is_active.is_(True),
            CostParticipant.is_app_user.is_(True),
        ).all()
        if participant.linked_user_id is not None
    }
    personal_label_map = personal_account_names()
    personal_user_list = personal_users()
    personal_user_map = {
        "persoenlich-flo": personal_user_list[0] if len(personal_user_list) > 0 else None,
        "persoenlich-desi": personal_user_list[1] if len(personal_user_list) > 1 else None,
    }

    def _personal_payload(slug: str) -> dict:
        user = personal_user_map.get(slug)
        participant = internal_participants.get(user.id) if user is not None else None
        return {
            "amount": personal_allocations.get(slug, Decimal("0.00")),
            "name": personal_label_map.get(slug, slug),
            "avatar_url": getattr(participant, "avatar_url", None) or getattr(user, "avatar_url", None),
            "avatar_initials": getattr(participant, "avatar_initials", None)
            or getattr(user, "avatar_initials", "??"),
        }

    return render_template(
        "main/index.html",
        month=month,
        summary=summary,
        recent_months=recent_months,
        notifications=notifications,
        community_account_cards=community_account_cards,
        shared_account_changes=shared_account_changes,
        personal_payouts={
            "first": _personal_payload("persoenlich-flo"),
            "second": _personal_payload("persoenlich-desi"),
        },
    )


@main_bp.route("/analytics")
@login_required
def analytics():
    if sync_user_participants():
        from app.extensions import db

        db.session.commit()
    month = g.current_month
    summary = current_app.extensions["saldo.month_service"].compute_summary(month)
    available_users = active_users()

    category_totals: dict[str, dict] = {}
    account_totals: dict[str, Decimal] = {}
    benefit_totals: dict[str, Decimal] = {}
    entry_rows = []
    personal_label_map = personal_account_names()

    for value in month.entry_values:
        entry = value.entry
        category = entry.category if entry else None
        account = category.account if category else None
        if (
            entry is None
            or category is None
            or account is None
            or not entry.is_active
            or not category.is_active
            or not account.is_active
        ):
            continue

        amount = to_decimal(value.planned_amount)
        is_personal_payout = account.slug in {"persoenlich-flo", "persoenlich-desi"}
        is_savings_target = account.slug in {"sparen", "urlaub", "freizeit"}
        category_key = (
            "personal-payout"
            if is_personal_payout
            else "savings-targets"
            if is_savings_target
            else str(category.id)
        )
        category_label = (
            "Persönliche Auszahlung"
            if is_personal_payout
            else "Sparkonten"
            if is_savings_target
            else category.name
        )
        category_account = (
            "Persönliche Auszahlung"
            if is_personal_payout
            else "Sparen & Verteilung"
            if is_savings_target
            else account.name
        )
        detail_entry_label = (
            personal_label_map.get(account.slug, account.name) if account.slug in {"persoenlich-flo", "persoenlich-desi"}
            else category.name if is_savings_target
            else entry.name
        )
        category_bucket = category_totals.setdefault(
            category_key,
            {
                "id": category_key,
                "label": category_label,
                "account": category_account,
                "value": Decimal("0.00"),
                "entries": {},
            },
        )
        category_bucket["value"] += amount
        category_bucket["entries"][detail_entry_label] = (
            category_bucket["entries"].get(detail_entry_label, Decimal("0.00")) + amount
        )

        account_label = (
            "Persönliche Auszahlung"
            if is_personal_payout
            else account.name
        )
        account_totals[account_label] = account_totals.get(account_label, Decimal("0.00")) + amount

        benefit_label = benefit_scope_label(entry.benefit_scope, available_users)
        benefit_totals[benefit_label] = benefit_totals.get(benefit_label, Decimal("0.00")) + amount

        entry_rows.append(
            {
                "label": f"{category.name} · {entry.name}",
                "value": amount,
            }
        )

    sorted_categories = sorted(
        category_totals.values(),
        key=lambda item: (-item["value"], item["account"], item["label"]),
    )
    category_entry_map = {
        str(item["id"]): {
            "label": item["label"],
            "account": item["account"],
            "labels": [label for label, _ in sorted(item["entries"].items(), key=lambda entry: (-entry[1], entry[0]))],
            "values": [float(value) for _, value in sorted(item["entries"].items(), key=lambda entry: (-entry[1], entry[0]))],
        }
        for item in sorted_categories
    }
    default_category_id = str(sorted_categories[0]["id"]) if sorted_categories else ""

    sorted_accounts = sorted(account_totals.items(), key=lambda item: (-item[1], item[0]))
    top_entries = sorted(entry_rows, key=lambda item: (-item["value"], item["label"]))[:10]
    historical_months = Month.query.order_by(Month.year.asc(), Month.month.asc()).all()
    budget_categories = (
        Category.query.join(Account)
        .filter(
            Category.is_active.is_(True),
            Account.slug == "gemeinschaftskonto",
        )
        .order_by(Category.sort_order.asc(), Category.name.asc())
        .all()
    )
    budget_timeline_rows = {
        category.id: {
            "label": category.name,
            "data": [],
        }
        for category in budget_categories
    }

    for historical_month in historical_months:
        month_totals = {category.id: Decimal("0.00") for category in budget_categories}
        for value in historical_month.entry_values:
            entry = value.entry
            category = entry.category if entry else None
            account = category.account if category else None
            if (
                entry is None
                or category is None
                or account is None
                or category.id not in month_totals
                or not entry.is_active
                or not category.is_active
                or not account.is_active
            ):
                continue
            month_totals[category.id] += to_decimal(value.planned_amount)

        for category in budget_categories:
            budget_timeline_rows[category.id]["data"].append(float(month_totals[category.id]))

    budget_timeline_datasets = [
        dataset
        for dataset in budget_timeline_rows.values()
        if any(value != 0 for value in dataset["data"])
    ]

    return render_template(
        "main/analytics.html",
        month=month,
        summary=summary,
        category_labels=[item["label"] for item in sorted_categories],
        category_values=[float(item["value"]) for item in sorted_categories],
        category_keys=[str(item["id"]) for item in sorted_categories],
        category_entry_map=category_entry_map,
        default_category_id=default_category_id,
        benefit_labels=[label for label, _ in sorted(benefit_totals.items(), key=lambda item: (-item[1], item[0]))],
        benefit_values=[float(value) for _, value in sorted(benefit_totals.items(), key=lambda item: (-item[1], item[0]))],
        account_labels=[label for label, _ in sorted_accounts],
        account_values=[float(value) for _, value in sorted_accounts],
        top_entry_labels=[item["label"] for item in top_entries],
        top_entry_values=[float(item["value"]) for item in top_entries],
        budget_timeline_labels=[item.label for item in historical_months],
        budget_timeline_datasets=budget_timeline_datasets,
    )


@main_bp.route("/health")
def health():
    return {"status": "ok"}, 200


@main_bp.route("/media/avatars/<path:filename>")
def uploaded_avatar(filename: str):
    return send_from_directory(current_app.config["AVATAR_UPLOAD_DIR"], filename)