from __future__ import annotations

from decimal import Decimal

from flask import Blueprint, flash, g, redirect, render_template, request, url_for

from app.auth import role_required
from app.extensions import db
from app.models import Account
from app.services import (
    build_new_household_draft,
    get_household_or_none,
    is_head_name_taken,
    list_enabled_options,
    list_households,
    normalize_search_term,
    parse_entry_form,
    serialize_admin_edit_snapshot,
    serialize_entry_edit_snapshot,
    write_audit_log,
)

quick_entry_bp = Blueprint("quick_entry", __name__, url_prefix="/quick-entry")


def _include_bride_side_param(source: object) -> bool:
    if not hasattr(source, "get"):
        return False

    value = getattr(source, "get")("include_bride_side", "")
    if not isinstance(value, str):
        return False

    return value.strip() == "1"


def _quick_entry_search_url(*, search_term: str = "", include_bride_side: bool = False) -> str:
    params: dict[str, str] = {}
    normalized_search_term = search_term.strip()
    if normalized_search_term:
        params["q"] = normalized_search_term
    if include_bride_side:
        params["include_bride_side"] = "1"
    return url_for("quick_entry.index", **params)


def _option_id_by_code(options: list[object], code: str) -> int | None:
    for option in options:
        if getattr(option, "option_code", None) == code:
            option_id = getattr(option, "id", None)
            if isinstance(option_id, int):
                return option_id
    return None


def _quick_entry_index_context() -> dict[str, object]:
    search_term = request.args.get("q", "").strip()
    include_bride_side = _include_bride_side_param(request.args)
    households = list_households(search_term=search_term, limit=20) if normalize_search_term(search_term) else []
    if not include_bride_side:
        households = [household for household in households if household.side != "bride_side"]
    households = sorted(
        households,
        key=lambda household: household.total_gift_amount > Decimal("0.00"),
    )
    return {
        "search_term": search_term,
        "include_bride_side": include_bride_side,
        "households": households,
    }


def _is_partial_request(expected_partial: str) -> bool:
    requested_partial = request.args.get("partial", "").strip()
    header_partial = request.headers.get("X-HW-Partial", "").strip()
    return requested_partial == expected_partial or header_partial == expected_partial


@quick_entry_bp.get("/")
@role_required("admin", "editor", "entry_only", "quick_editor")
def index() -> str:
    context = _quick_entry_index_context()
    if _is_partial_request("search-results"):
        return render_template("quick_entry/_search_results.html", **context)
    return render_template("quick_entry/index.html", **context)


@quick_entry_bp.get("/households/new")
@role_required("admin", "editor", "entry_only", "quick_editor")
def new_household() -> str:
    search_term = request.args.get("q", "").strip()
    include_bride_side = _include_bride_side_param(request.args)
    gift_method_options = list_enabled_options("gift_method")
    gift_scene_options = list_enabled_options("gift_scene")
    return render_template(
        "quick_entry/new.html",
        search_term=search_term,
        include_bride_side=include_bride_side,
        default_gift_method_id=_option_id_by_code(gift_method_options, "cash"),
        default_gift_scene_id=_option_id_by_code(gift_scene_options, "wedding_day"),
    )


@quick_entry_bp.get("/households/<int:household_id>/edit")
@role_required("admin", "editor", "entry_only", "quick_editor")
def edit_household(household_id: int):
    household = get_household_or_none(household_id)
    if household is None:
        flash("未找到要修改的户信息。", "error")
        return redirect(url_for("quick_entry.index"))

    gift_method_options = list_enabled_options("gift_method")
    gift_scene_options = list_enabled_options("gift_scene")
    context = {
        "household": household,
        "search_term": request.args.get("q", "").strip(),
        "include_bride_side": _include_bride_side_param(request.args),
        "gift_method_options": gift_method_options,
        "gift_scene_options": gift_scene_options,
        "default_gift_method_id": _option_id_by_code(gift_method_options, "cash"),
        "default_gift_scene_id": _option_id_by_code(gift_scene_options, "wedding_day"),
    }
    if _is_partial_request("edit-modal"):
        return render_template("quick_entry/_edit_modal.html", **context)
    return render_template("quick_entry/edit.html", **context)


@quick_entry_bp.post("/households/<int:household_id>/edit")
@role_required("admin", "editor", "entry_only", "quick_editor")
def update_household(household_id: int):
    household = get_household_or_none(household_id)
    if household is None:
        flash("未找到要修改的户信息。", "error")
        return redirect(url_for("quick_entry.index"))

    search_term = request.form.get("q", "").strip()
    include_bride_side = _include_bride_side_param(request.form)
    redirect_to_search = _quick_entry_search_url(search_term=search_term, include_bride_side=include_bride_side)
    redirect_to_self = url_for(
        "quick_entry.edit_household",
        household_id=household_id,
        q=search_term,
        **({"include_bride_side": "1"} if include_bride_side else {}),
    )

    submitted_version = request.form.get("version", "").strip()
    try:
        version = int(submitted_version)
    except ValueError:
        flash("表单版本无效，请重新打开该户信息后再试。", "error")
        return redirect(redirect_to_self)

    if version != household.version:
        flash("该户信息已被其他人更新，请刷新后重新确认再保存。", "warning")
        return redirect(redirect_to_self)

    gift_method_options = list_enabled_options("gift_method")
    gift_scene_options = list_enabled_options("gift_scene")
    payload, errors = parse_entry_form(
        dict(request.form),
        valid_method_ids={option.id for option in gift_method_options},
        valid_scene_ids={option.id for option in gift_scene_options},
    )
    head_name = request.form.get("head_name", "").strip()
    if not head_name:
        errors.append("户主姓名不能为空。")
    elif is_head_name_taken(head_name, excluding_household_id=household_id):
        errors.append("该户主姓名已存在，请换一个名字或直接录入现有户。")
    if errors:
        for error in errors:
            flash(error, "error")
        return redirect(redirect_to_self)

    before_snapshot = serialize_entry_edit_snapshot(household)
    household.head_name = head_name
    for field_name, value in payload.items():
        setattr(household, field_name, value)

    current_account = g.current_account
    if isinstance(current_account, Account):
        household.updated_by = current_account.id

    if serialize_entry_edit_snapshot(household) == before_snapshot:
        flash("没有检测到需要保存的变化。", "warning")
        db.session.rollback()
        return redirect(redirect_to_search)

    household.version += 1
    after_snapshot = serialize_entry_edit_snapshot(household)
    write_audit_log(
        action_type="update_household_entry",
        target_type="household",
        actor=current_account if isinstance(current_account, Account) else None,
        target_id=household.id,
        target_display_name=household.head_name,
        before_data=before_snapshot,
        after_data=after_snapshot,
        commit=False,
    )
    db.session.commit()
    flash(f"已保存 {household.head_name} 的礼金信息。", "success")
    return redirect(redirect_to_search)


@quick_entry_bp.post("/households")
@role_required("admin", "editor", "entry_only", "quick_editor")
def create_household():
    search_term = request.form.get("q", "").strip() or request.form.get("head_name", "").strip()
    include_bride_side = _include_bride_side_param(request.form)
    redirect_to_search = _quick_entry_search_url(search_term=search_term, include_bride_side=include_bride_side)
    redirect_to_self = url_for(
        "quick_entry.new_household",
        q=search_term,
        **({"include_bride_side": "1"} if include_bride_side else {}),
    )

    gift_method_options = list_enabled_options("gift_method")
    gift_scene_options = list_enabled_options("gift_scene")
    payload, errors = parse_entry_form(
        dict(request.form),
        valid_method_ids={option.id for option in gift_method_options},
        valid_scene_ids={option.id for option in gift_scene_options},
    )
    if errors:
        for error in errors:
            flash(error, "error")
        return redirect(redirect_to_self)

    head_name = request.form.get("head_name", "").strip()
    if not head_name:
        flash("户主姓名不能为空。", "error")
        return redirect(redirect_to_self)

    if is_head_name_taken(head_name):
        flash("该户主姓名已存在，请先搜索现有户后直接录入礼金。", "error")
        return redirect(redirect_to_self)

    household = build_new_household_draft()
    household.head_name = head_name
    household.note = request.form.get("note", "").strip() or None
    for field_name, value in payload.items():
        setattr(household, field_name, value)
    if household.actual_attendee_count > 0 and household.attendance_status == "pending":
        household.attendance_status = "attending"

    current_account = g.current_account
    if isinstance(current_account, Account):
        household.created_by = current_account.id
        household.updated_by = current_account.id

    db.session.add(household)
    db.session.flush()
    write_audit_log(
        action_type="create_household_quick_entry",
        target_type="household",
        actor=current_account if isinstance(current_account, Account) else None,
        target_id=household.id,
        target_display_name=household.head_name,
        after_data=serialize_admin_edit_snapshot(household),
        commit=False,
    )
    db.session.commit()
    flash(f"已快速创建 {household.head_name} 并记录礼金。", "success")
    return redirect(redirect_to_search)