from __future__ import annotations

from flask import Blueprint, flash, redirect, render_template, request, url_for
from flask.typing import ResponseReturnValue

from app.extensions import db
from app.services import (
    check_share_token,
    get_household_or_none,
    household_has_active_gift_records,
    is_head_name_taken,
    list_enabled_options,
    list_households,
    normalize_search_term,
    parse_admin_form,
    recalculate_household_gift_summary,
    serialize_admin_edit_snapshot,
    write_audit_log,
)

share_bp = Blueprint("share", __name__, url_prefix="/s")


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


@share_bp.get("/<string:token>")
def search_page(token: str) -> ResponseReturnValue:
    check_result = check_share_token(token)
    if not check_result.ok:
        return render_template("share/invalid.html", reason=check_result.reason), 404

    search_term = request.args.get("q", "").strip()
    households = list_households(search_term=search_term, limit=20) if normalize_search_term(search_term) else []
    template_name = "share/_results.html" if _is_partial_request("results") else "share/search.html"
    return render_template(
        template_name,
        token=token,
        search_term=search_term,
        households=households,
    )


@share_bp.get("/<string:token>/households/<int:household_id>/edit")
def edit_page(token: str, household_id: int) -> ResponseReturnValue:
    check_result = check_share_token(token)
    if not check_result.ok:
        return render_template("share/invalid.html", reason=check_result.reason), 404

    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("share.search_page", token=token))

    return render_template(
        "share/edit.html",
        token=token,
        household=household,
        search_term=request.args.get("q", "").strip(),
        relation_category_options=list_enabled_options("relation_category"),
        tag_options=list_enabled_options("tag"),
        gift_method_options=list_enabled_options("gift_method"),
        gift_scene_options=list_enabled_options("gift_scene"),
    )


@share_bp.post("/<string:token>/households/<int:household_id>/edit")
def update_household(token: str, household_id: int) -> ResponseReturnValue:
    check_result = check_share_token(token)
    if not check_result.ok:
        return render_template("share/invalid.html", reason=check_result.reason), 404

    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("share.search_page", token=token))

    search_term = request.form.get("q", "").strip()
    redirect_to_search = url_for("share.search_page", token=token, q=search_term) if search_term else url_for("share.search_page", token=token)
    redirect_to_self = (
        url_for("share.edit_page", token=token, household_id=household_id, q=search_term)
        if search_term
        else url_for("share.edit_page", token=token, household_id=household_id)
    )

    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)

    relation_category_options = list_enabled_options("relation_category")
    tag_options = list_enabled_options("tag")
    gift_method_options = list_enabled_options("gift_method")
    gift_scene_options = list_enabled_options("gift_scene")
    payload, errors = parse_admin_form(
        dict(request.form),
        raw_tag_option_ids=request.form.getlist("tag_option_ids_json"),
        valid_relation_category_ids={option.id for option in relation_category_options},
        relation_detail_parent_map={},
        valid_tag_ids={option.id for option in tag_options},
        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 = str(payload["head_name"])
    if is_head_name_taken(head_name, excluding_household_id=household_id):
        flash("户主姓名已存在，请修改后重试。", "error")
        return redirect(redirect_to_self)

    if household_has_active_gift_records(household_id):
        payload.pop("total_gift_amount", None)
        payload.pop("gift_method_option_id", None)
        payload.pop("gift_scene_option_id", None)

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

    if household_has_active_gift_records(household_id):
        recalculate_household_gift_summary(household)

    if serialize_admin_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
    share_link = check_result.link
    write_audit_log(
        action_type="update_household_share_link",
        target_type="household",
        actor_username=f"share:{share_link.token}" if share_link is not None else "share",
        target_id=household.id,
        target_display_name=household.head_name,
        before_data=before_snapshot,
        after_data=serialize_admin_edit_snapshot(household) | {
            "share_link_id": share_link.id if share_link is not None else None,
            "share_link_label": share_link.label if share_link is not None else None,
        },
        commit=False,
    )
    db.session.commit()
    flash(f"已保存 {household.head_name} 的信息。", "success")
    return redirect(redirect_to_search)