/** Task history sub-view: filter chips + search + the timeline of entries.
 *
 * Extracted from the panel (renderers/ pattern). State the panel owns —
 * the active filter, the search text, the currency symbol — plus the
 * callbacks that mutate it or open the edit dialog are passed in via
 * HistoryContext, keeping these functions pure of component internals.
 */

import { html, nothing } from "lit";
import { t, formatDateTime, STATUS_ICONS } from "../styles";
import type { MaintenanceTask, HistoryEntry, HomeAssistant } from "../types";
import "../components/history-photo";

export interface HistoryContext {
  lang: string;
  /** Home Assistant object — used to sign completion-photo URLs. */
  hass: HomeAssistant;
  /** Active type filter, or null for "all". */
  filter: string | null;
  /** Free-text search over entry notes. */
  search: string;
  /** Currency symbol for cost display (defaults to €). */
  currencySymbol: string;
  setFilter: (filter: string | null) => void;
  setSearch: (search: string) => void;
  openEdit: (entry: HistoryEntry) => void;
  /** v2.20 (#83): unit + delta-vs-previous for reading-task entries. */
  readingUnit?: string | null;
  readingDelta?: (entry: HistoryEntry) => number | null;
}

const _FILTER_TYPES = ["completed", "skipped", "missed", "reset", "triggered"] as const;

export function renderHistoryFilters(task: MaintenanceTask, ctx: HistoryContext) {
  const L = ctx.lang;
  return html`
    <div class="history-filters-new">
      <div class="filter-chips">
        ${_FILTER_TYPES.map((type) => {
          const count = task.history.filter((h) => h.type === type).length;
          if (count === 0) return nothing;
          return html`
            <span class="filter-chip ${ctx.filter === type ? "active" : ""}"
              @click=${() => ctx.setFilter(ctx.filter === type ? null : type)}>
              ${t(type, L)} (${count})
            </span>
          `;
        })}
        ${ctx.filter ? html`<span class="filter-chip clear" @click=${() => ctx.setFilter(null)}>${t("show_all", L)}</span>` : nothing}
      </div>
      <div class="filter-controls">
        <input type="text" class="search-input" placeholder="${t("search_notes", L)}..." .value=${ctx.search} @input=${(e: Event) => ctx.setSearch((e.target as HTMLInputElement).value)} />
      </div>
    </div>
  `;
}

export function renderHistoryList(task: MaintenanceTask, ctx: HistoryContext) {
  const L = ctx.lang;
  let filtered = ctx.filter
    ? task.history.filter((h) => h.type === ctx.filter)
    : task.history;

  // Apply search filter
  if (ctx.search) {
    const search = ctx.search.toLowerCase();
    filtered = filtered.filter((h) => h.notes?.toLowerCase().includes(search));
  }

  if (filtered.length === 0) {
    return html`<p class="empty">${t("no_history", L)}</p>`;
  }

  return html`
    <div class="history-timeline">
      ${[...filtered].reverse().map((entry: HistoryEntry) => renderHistoryEntry(entry, ctx))}
    </div>
  `;
}

export function renderHistoryEntry(entry: HistoryEntry, ctx: HistoryContext) {
  const L = ctx.lang;
  // v2.2.0: only "lifecycle + cost-bearing" entries are user-editable.
  // Triggers are auto-generated by sensors and shouldn't be retroactively
  // rewritten. Allow edits for completed / reset / skipped entries.
  const editable = ["completed", "reset", "skipped"].includes(entry.type);
  return html`
    <div class="history-entry">
      <div class="history-icon ${entry.type}">
        <ha-icon .icon=${STATUS_ICONS[entry.type] || "mdi:circle"}></ha-icon>
      </div>
      <div class="history-content">
        <div class="history-row">
          <strong>${t(entry.type, L)}</strong>
          ${entry.auto ? html`<span class="history-auto-badge">${t("history_auto", L)}</span>` : nothing}
          ${editable
            ? html`<button class="history-edit-btn"
                     title=${t("history_edit_button", L) || "Edit entry"}
                     @click=${() => ctx.openEdit(entry)}>
                <ha-icon icon="mdi:pencil"></ha-icon>
              </button>`
            : nothing}
        </div>
        <div class="history-date">${formatDateTime(entry.timestamp, L)}</div>
        ${entry.notes ? html`<div>${entry.notes}</div>` : nothing}
        ${entry.photo_doc_id
          ? html`<maintenance-history-photo .hass=${ctx.hass} .docId=${entry.photo_doc_id}></maintenance-history-photo>`
          : nothing}
        <div class="history-details">
          ${entry.cost != null ? html`<span>${t("cost", L)}: ${entry.cost.toFixed(2)} ${ctx.currencySymbol}</span>` : nothing}
          ${entry.duration != null ? html`<span>${t("duration", L)}: ${entry.duration} min</span>` : nothing}
          ${entry.trigger_value != null ? html`<span>${t("trigger_val", L)}: ${entry.trigger_value}</span>` : nothing}
          ${entry.reading_value != null
            ? html`<span>${t("reading_label", L)}: ${entry.reading_value}${ctx.readingUnit ? ` ${ctx.readingUnit}` : ""}${(() => {
                const d = ctx.readingDelta?.(entry);
                return d == null ? "" : ` (${d >= 0 ? "+" : ""}${Number(d.toFixed(3))})`;
              })()}</span>`
            : nothing}
        </div>
      </div>
    </div>
  `;
}