import { addDays } from '../habits/calendar';
import { dateSchema, type Schedule } from '../habits/contracts';
import { dailyAction, detail } from './daily';
import { fields, type Context, type ControlData, type Message, type Reply } from './types';
import { button, screen, modal, pages, row, text, componentMessage, display, panel, section, listSize, listPage, pageLabel } from './ui';

const weekdays = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
function scheduleLabel(schedule: Schedule): string {
  if (schedule.type === 'daily') return 'Every day';
  if (schedule.type === 'weekdays') return schedule.days.map(day => weekdays[day]).join(', ');
  if (schedule.type === 'interval') return `Every ${schedule.every} days from ${schedule.anchor}`;
  return `Every ${schedule.every} weeks on ${weekdays[schedule.weekday]} from ${schedule.anchor}`;
}

export function history(c: Context, data: ControlData = {}): Reply {
  const all = c.service.list(true);
  const page = listPage(data.page, all.length);
  const state: ControlData = { date: data.date ?? c.service.today, mode: 'history', today: false };
  return componentMessage(c, [
    panel([display(`## History\n${text(c.service.user.timezone)} · ${pageLabel(page, all.length)}\n${all.length ? 'Open a habit to inspect or correct a date. Archived habits are included.' : 'No habits yet. Use /habits to create one.'}`)]),
    ...all.slice(page * listSize, (page + 1) * listSize).map(h => panel([
      section(`**${text(h.name)}**\n${h.archived ? 'Archived · ' : ''}Tracked since ${h.createdDate}`, button(c, 'Open history', 'history.detail', { ...state, habitId: h.id })),
    ], c.service.settings(h.id).mainColor)),
    ...pages(c, 'history', { ...state, page }, all.length, listSize),
  ]);
}

function dateForm(c: Context, data: ControlData): Reply {
  c.service.owned(data.habitId!);
  return modal(c, 'Choose history date', 'history.date', data, [{ id: 'date', label: 'Calendar date (YYYY-MM-DD)', value: data.date ?? c.service.today, max: 10 }]);
}

// Keep the dated editor and all mutation checks in daily.ts. Its opaque payloads
// preserve mode/today, so subsequent saves, forms and task pages return here.
function withNavigation(c: Context, data: ControlData, reply: Reply): Reply {
  if (![4, 7].includes(reply.type)) return reply;
  const d = c.service.day(data.habitId!, data.date!);
  const state: ControlData = { habitId: data.habitId, date: data.date, mode: 'history', today: false, page: 0 };
  const navigation = [
    ...(data.date! > '1970-01-01' ? [button(c, 'Previous date', 'history.detail', { ...state, date: addDays(data.date!, -1) })] : []),
    ...(data.date! < '9998-12-31' ? [button(c, 'Next date', 'history.detail', { ...state, date: addDays(data.date!, 1) })] : []),
    button(c, 'Change date', 'history.form', state),
    button(c, 'Choose habit', 'history', { date: data.date }),
  ];
  const explanation = !d.requirements ? 'Read-only · This habit was not tracked yet.'
    : d.requirements.archived ? 'Read-only · This habit was archived on this date.'
    : !d.due ? 'Read-only · Day off; nothing is scheduled for this date.' : '';
  const body = reply.data as Message;
  const requirements = d.requirements ? `${d.method === 'manual' ? 'Checkbox' : d.method === 'count' ? 'Count' : 'Tasks'} · ${scheduleLabel(d.requirements.schedule)}\n` : '';
  const [card, ...rest] = body.components ?? [];
  if (card?.type === 17) {
    const children = card.components as import('./types').DiscordComponent[];
    const metadata = `${requirements}${explanation}`.trim();
    return { ...reply, data: { ...body, components: [{ ...card, components: [children[0]!, ...(metadata ? [display(metadata)] : []), ...children.slice(1)] }, ...rest, row(...navigation)] } };
  }
  return reply;
}

export function historyAction(c: Context, action: string, data: ControlData): Reply | undefined {
  if (action === 'history') return history(c, data);
  if (action === 'history.select') return dateForm(c, { ...data, habitId: c.interaction.data?.values?.[0], page: 0 });
  if (action === 'history.form') return dateForm(c, data);
  if (action === 'history.date') {
    const parsed = dateSchema.safeParse(fields(c.interaction).date?.trim());
    if (!parsed.success) return screen(c, 'Enter a real calendar date as YYYY-MM-DD, from 1970 through 9998.', [row(button(c, 'Change date', 'history.form', data))]);
    data = { ...data, date: parsed.data, page: 0 };
    action = 'history.detail';
  }
  if (action === 'history.detail' || (data.mode === 'history' && action.startsWith('daily.'))) {
    const state = { ...data, date: dateSchema.parse(data.date), mode: 'history', today: false };
    const reply = action === 'history.detail' ? detail(c, state) : dailyAction(c, action, state);
    return reply && withNavigation(c, state, reply);
  }
}