import PocketBase from 'pocketbase';
import {
  AppSettings,
  DEFAULT_SETTINGS,
  OrderItem,
  OrderItemAttachment,
  AttachmentSource,
  DriverLocation,
} from './types';
import { clearCache as clearItemsCache } from './itemsCache';

const POCKETBASE_URL = process.env.NEXT_PUBLIC_POCKETBASE_URL || 'https://pocketbase-gnqc88suy8fqk6wyryjjdpvl.169.239.180.130.sslip.io';

export const pb = new PocketBase(POCKETBASE_URL);

// Disable auto-cancellation so React re-renders don't kill in-flight requests
pb.autoCancellation(false);

// Auth helpers
export const isAuthenticated = () => pb.authStore.isValid;

export const getCurrentUser = () => pb.authStore.model;

export const logout = () => {
  pb.authStore.clear();
  // Drop cached items so the next driver who logs in on this
  // device doesn't briefly see the previous driver's list.
  clearItemsCache();
  if (typeof window !== 'undefined') {
    window.location.href = '/login/';
  }
};

export const login = async (email: string, password: string) => {
  return await pb.collection('users').authWithPassword(email, password);
};

// PB `order_items` schema (verified live 2026-07-08):
//   drv_id           = relation -> users (canonical "assigned driver" field)
//   driver           = legacy/parallel driver field (only set on 1 row)
//   supplier         = relation -> suppliers (singular)
//   item_status real values: assigned, collection_pool, pending,
//                           collected, problem, ...
//   drv_status real values: assigned, en_route, collected, failed, '' (empty),
//                           unassigned
//   po_description   = supplier-facing line ("M20×40 nut sku 11243…")
//   description      = customer-facing line
//   order_qty        = supplier-facing qty (falls back to quantity)
//   quantity         = customer-facing qty
//   in_stock         = NOT IN PB YET — add before relying on it
//   ready_for_collection = NOT IN PB YET (2026-07-08) — do NOT filter on it;
//                         referencing any field PB doesn't have throws 400.
//                         item_status alone ("assigned" / "collection_pool")
//                         is sufficient for the current driver/pool queries.
//   assigned_at      = ISO timestamp, populated server-side on assignment
//   problem_notes    = driver-written audit trail of failed collections
// Unknown status values are NOT rejected by PB — they silently match
// nothing. Always use the exact string below.

// ---------- Hydration helper ----------
// PB query builder can't always do the supplier expand (some deployments
// strip expand support). This helper takes raw records and, if supplier
// isn't already expanded, batch-fetches suppliers by id and stitches
// them back into item.expand.supplier. Shared by every fetch below.
const hydrateSuppliers = async (items: OrderItem[]): Promise<OrderItem[]> => {
  const missing = Array.from(new Set(
    items
      .filter((it) => !it.expand?.supplier && (it as any).supplier)
      .map((it) => (it as any).supplier as string)
  ));
  if (missing.length === 0) return items;

  let supplierMap = new Map<string, any>();
  try {
    const filter = missing.map((id) => `id = "${id}"`).join(' || ');
    const suppliers = await pb.collection('suppliers').getFullList({ filter });
    supplierMap = new Map(suppliers.map((s: any) => [s.id, s]));
  } catch {
    return items;
  }

  return items.map((it) => {
    if (it.expand?.supplier) return it;
    const supplierId = (it as any).supplier;
    const supplier = supplierId ? supplierMap.get(supplierId) : null;
    if (!supplier) return it;
    return {
      ...it,
      expand: { ...(it.expand || {}), supplier },
    } as OrderItem;
  });
};

// ---------- 1. ASSIGNED — only items with drv_id = current user ----------
// Filter uses `drv_id` (the canonical assigned-driver relation), not
// `driver` (which is a legacy/parallel field only set on a handful of
// rows). drv_id is the field per the project brief (2026-07-07).
export const getMyAssignedItems = async (): Promise<OrderItem[]> => {
  const user = getCurrentUser();
  if (!user) return [];
  try {
    const items = await pb.collection('order_items').getFullList<OrderItem>({
      filter: `drv_id = "${user.id}" && item_status = "assigned"`,
      expand: 'supplier,order,purchase_order',
      sort: 'supplier.suppliername',
    });
    return items;
  } catch {
    const items = await pb.collection('order_items').getFullList<OrderItem>({
      filter: `drv_id = "${user.id}" && item_status = "assigned"`,
    });
    return hydrateSuppliers(items);
  }
};

// Backwards-compat alias — keep old call sites working during the refactor.
export const getAssignedCollections = getMyAssignedItems;

// ---------- 2. POOL — every collection_pool item in the system ----------
// Pool means "open for any driver to claim". The driver app shows ALL
// pool rows here so the driver can see what's available before claiming.
// No driver filter on purpose.
export const getPoolItems = async (): Promise<OrderItem[]> => {
  try {
    const items = await pb.collection('order_items').getFullList<OrderItem>({
      filter: `item_status = "collection_pool"`,
      expand: 'supplier,order,purchase_order',
      sort: 'supplier.suppliername',
    });
    return items;
  } catch {
    const items = await pb.collection('order_items').getFullList<OrderItem>({
      filter: `item_status = "collection_pool"`,
    });
    return hydrateSuppliers(items);
  }
};

// ---------- 3. PROBLEMS — every flagged item in the system ----------
// Items with problem_flag=true OR item_status='problem'. No driver
// filter — problems are operational visibility, not personal lists.
export const getProblemItems = async (): Promise<OrderItem[]> => {
  try {
    const items = await pb.collection('order_items').getFullList<OrderItem>({
      filter: `problem_flag = true || item_status = "problem"`,
      expand: 'supplier,order,purchase_order',
      sort: '-updated',
    });
    return items;
  } catch {
    const items = await pb.collection('order_items').getFullList<OrderItem>({
      filter: `problem_flag = true || item_status = "problem"`,
    });
    return hydrateSuppliers(items);
  }
};

// Update order item status when collected. This is the canonical
// driver-side collection writer — the dashboard's
// `/api/v1/order-items/[id]/status` route covers the same patch from
// the operator side, so keep the field set aligned.
//
// Status flow on collection:
//   - Always sets:
//       * `item_status = "collected"`           (operator-side)
//       * `drv_status  = "collected"`           (driver-side status machine)
//       * `drv_collected_at = now`              (timestamp of physical pickup)
//       * `qty_collected = receivedQty`         (audit: actual qty picked up)
//   - Always sets `collection_photo` if a file was supplied.
//   - Quantity-mismatch behaviour:
//       * Full  (received === expected) → no extra flags. Clean collection.
//       * Partial (0 < received < expected) → `problem_flag = true`,
//         `problem_type = "stock"`, and a stock-shortage note in
//         `problem_notes`. The operator still sees the item as
//         collected but the problem flag surfaces it in the Problems
//         tab so a follow-up can be planned.
//       * Over   (received > expected) → `problem_flag = true` and a
//         `problem_notes` entry explaining the overage. No
//         `problem_type` because it's not a stock issue — the supplier
//         gave more than ordered, which can mean a packing error or a
//         promo. We leave the type empty so the operator picks.
//
// The helper intentionally doesn't compute `expected` itself — the
// caller passes `expectedQty` so the source of truth for "what was
// ordered" stays at the call site (where the same number was just
// shown to the driver in the modal).
export const updateCollectionStatus = async (
  id: string,
  status: string,
  data: {
    qty_collected?: number;
    notes?: string;
    collected_date?: string;
    photo?: File | null;
    expectedQty?: number;
    problem_type?: string;
    problem_flag?: boolean;
  }
) => {
  const patch: Record<string, unknown> = {
    item_status: status,
    drv_status: 'collected',
    drv_collected_at: new Date().toISOString(),
    qty_collected: data.qty_collected,
    collected_date: data.collected_date ?? new Date().toISOString(),
  };

  // Only forward the optional photo if a file was actually attached.
  // Passing `null`/undefined to a PB file field would clear an existing
  // attachment on subsequent updates, which we don't want for a
  // re-collect after the first one.
  if (data.photo) patch.collection_photo = data.photo;

  // Notes field keeps the driver's free-text commentary.
  if (data.notes !== undefined) patch.notes = data.notes;

  // Quantity-mismatch handling — see the doc-comment above.
  const received = typeof data.qty_collected === 'number' ? data.qty_collected : 0;
  const expected = typeof data.expectedQty === 'number' ? data.expectedQty : 0;
  if (expected > 0 && received > 0 && received < expected) {
    // Partial — short pickup. Flag so it surfaces in Problems.
    patch.problem_flag = true;
    patch.problem_type = 'stock';
    const userNote = (data.notes ?? '').trim();
    const autoNote = `Partial collection: ${received} of ${expected} units`;
    patch.problem_notes = userNote ? `${autoNote} — ${userNote}` : autoNote;
  } else if (expected > 0 && received > expected) {
    // Over-collection — supplier gave more than ordered. Flag without
    // a stock type so the operator picks the right follow-up.
    patch.problem_flag = true;
    patch.problem_type = '';
    const userNote = (data.notes ?? '').trim();
    const autoNote = `Over collection: ${received} units received against ${expected} ordered`;
    patch.problem_notes = userNote ? `${autoNote} — ${userNote}` : autoNote;
  }

  return await pb.collection('order_items').update(id, patch);
};

// ---------- Attachments ----------
// Upload a pickup photo by appending it to the order_item's
// `order_item_attachements` file field (PB file field, max multi).
// Uses the `fieldName+` append syntax so each upload is preserved
// alongside any previous files rather than replacing them.
//
// The source/notes params are accepted for interface compatibility
// but cannot be stored per-file without a separate attachment collection.
// Both are safe to drop here since the driver always uses
// source=driver_proof and notes go into order_items.notes separately.
//
// Throws on PB errors so the caller can roll back the status change.
export const uploadOrderItemAttachment = async (params: {
  orderItemId: string;
  file: File;
  source?: AttachmentSource;
  notes?: string;
}): Promise<OrderItemAttachment> => {
  const { orderItemId, file } = params;

  const formData = new FormData();
  // fieldName+ = append (never overwrite) existing files on the row
  formData.append('order_item_attachements+', file);

  const updated = await pb.collection('order_items').update(orderItemId, formData);
  // PB returns the updated order_item; extract the last filename as the
  // "id" for the returned OrderItemAttachment shape.
  const filenames: string[] = (updated as unknown as { order_item_attachements?: string[] }).order_item_attachements ?? [];
  const filename = filenames[filenames.length - 1] ?? file.name;

  return {
    id: filename, // no separate attachment id; filename is the key
    order_item: orderItemId,
    filename,
    file: filename,
    source: 'driver_proof',
    uploaded_at: new Date().toISOString(),
  } as unknown as OrderItemAttachment;
};

// List attachment filenames for an order item by fetching the file list
// from the order_item_attachements file field on the order_items row.
export const listOrderItemAttachments = async (
  orderItemId: string
): Promise<OrderItemAttachment[]> => {
  const item = await pb.collection('order_items').getOne(orderItemId);
  const filenames: string[] = (item as unknown as { order_item_attachements?: string[] }).order_item_attachements ?? [];
  return filenames.map((filename) => ({
    id: filename,
    order_item: orderItemId,
    filename,
    file: filename,
    source: 'driver_proof' as const,
    uploaded_at: '',
  })) as unknown as OrderItemAttachment[];
};

// ---------- Display helpers ----------
// Per the project brief:
//   po_description is the supplier-facing line (preferred on the PO
//   pickup screen); description is the customer-facing line. We always
//   show the supplier-facing line when it's there, and fall back to the
//   customer-facing one for legacy rows.
export const getItemDisplayDescription = (item: OrderItem): string => {
  const po = (item.po_description || '').trim();
  if (po) return po;
  return (item.description || '').trim() || '—';
};

// order_qty is the supplier-facing quantity (preferred on the pickup
// screen); quantity is the customer-facing quantity. Per the brief:
// order_qty "falls back to quantity if blank". We honor that order.
export const getItemDisplayQty = (item: OrderItem): number => {
  const oq = item.order_qty;
  if (typeof oq === 'number' && !Number.isNaN(oq) && oq > 0) return oq;
  const q = item.quantity;
  if (typeof q === 'number' && !Number.isNaN(q) && q > 0) return q;
  return 0;
};

// ---------- Driver-side claim action ----------
// When the driver sees an open item in Pool and wants to take it:
// set drv_id = me, item_status = "assigned", assigned_at = now.
export const claimItemForDriver = async (itemId: string) => {
  const user = getCurrentUser();
  if (!user) throw new Error('Not signed in');
  return await pb.collection('order_items').update(itemId, {
    drv_id: user.id,
    item_status: 'assigned',
    drv_status: 'assigned',
    assigned_at: new Date().toISOString(),
  });
};

// Report a problem on an order item
export const reportProblem = async (
  orderItemId: string,
  problemType: string,
  description: string
) => {
  return await pb.collection('order_items').update(orderItemId, {
    item_status: 'problem',
    problem_type: problemType,
    problem_flag: true,
    problem_notes: description,
  });
};

// Location tracking - tries to save, fails silently if table doesn't exist.
// IMPORTANT: PB schema (verified live 2026-07-08) stores the driver
// relation under `relation`, not `driver`. Writing to `driver` 400s and
// the row is never created — that's why the map polyline has been empty.
// If we ever migrate PB to rename the field back to `driver` (it should
// be — `relation` is a confusing name), update this + getDriverTrail.
export const saveDriverLocation = async (location: Omit<DriverLocation, 'id'>) => {
  try {
    return await pb.collection('driver_locations').create(location);
  } catch (e) {
    // Log now (was silent) — silent catches are how the `driver`-field
    // bug stayed hidden for months.
    console.warn('[saveDriverLocation] failed:', e instanceof Error ? e.message : e);
  }
};

// Get driver's location trail for today (for map polyline).
export const getDriverTrail = async (driverId: string) => {
  try {
    const today = new Date();
    today.setHours(0, 0, 0, 0);
    const records = await pb.collection('driver_locations').getFullList({
      filter: `relation = "${driverId}" && timestamp >= "${today.toISOString()}"`,
      sort: 'timestamp',
    });
    return records as unknown as DriverLocation[];
  } catch (e) {
    console.warn('[getDriverTrail] failed:', e instanceof Error ? e.message : e);
    return [];
  }
};

// Settings helpers
const SETTINGS_KEY = '1driver_settings';

export const getSettings = (): AppSettings => {
  if (typeof window === 'undefined') return DEFAULT_SETTINGS;
  const saved = localStorage.getItem(SETTINGS_KEY);
  if (saved) {
    try {
      return { ...DEFAULT_SETTINGS, ...JSON.parse(saved) };
    } catch {
      return DEFAULT_SETTINGS;
    }
  }
  return DEFAULT_SETTINGS;
};

export const saveSettings = (settings: Partial<AppSettings>) => {
  if (typeof window === 'undefined') return;
  const current = getSettings();
  const updated = { ...current, ...settings };
  localStorage.setItem(SETTINGS_KEY, JSON.stringify(updated));
  return updated;
};