/** Supplier-payment commands. All mutations run in one PB transaction. */
const REQUESTS = "supplier_payment_requests";
const ITEMS = "order_items";
const REQUEST_FIELDS = ["order", "supplier", "items", "status", "requested_by", "paid_by", "paid_at", "cancellation_reason", "documents", "item_snapshot", "revision", "history"];
const BLOCKED_STAGES = ["ready_delivery", "assigned", "collected", "stock_verified", "picking", "ready_invoice", "invoiced", "stock_booked", "with_driver", "checked_in", "completed", "delivered", "delivery_note"];
const NEW_HOLD_STAGES = ["pending", "processed", "po_generated", "collection_pool", "approval_needed", "approval_rejected"];

function fail(message, status) {
  throw new ApiError(status || 409, message);
}
function plain(record) { return JSON.parse(JSON.stringify(record)); }
function array(value) { return Array.isArray(value) ? value : (value ? [value] : []); }
function text(value, max) { return String(value || "").trim().slice(0, max || 2000); }
function active(record) { return ["draft", "pending"].indexOf(record.getString("status")) !== -1; }
function lookup(app, name, id) {
  try { return app.findRecordById(name, text(id, 64)); }
  catch (_) { fail("Payment request or order item was not found. Refresh and try again.", 404); }
}
function assertSchema(app) {
  const required = { order_items: ["payment_status", "payment_request", "ready_for_collection", "order_item_attachements"], supplier_payment_requests: REQUEST_FIELDS };
  Object.keys(required).forEach((name) => {
    let collection;
    try { collection = app.findCollectionByNameOrId(name); }
    catch (_) { fail("Supplier payments need the PocketBase schema migration before use.", 503); }
    required[name].forEach((field) => {
      let found;
      try { found = collection.fields.getByName(field); } catch (_) { found = null; }
      if (!found) fail("Supplier payments need the PocketBase schema migration (" + name + "." + field + ").", 503);
    });
  });
}
function actor(body) {
  if (!body.actor || !text(body.actor.id, 64) || !text(body.actor.name, 200)) fail("A verified payment actor is required.", 422);
  return { id: text(body.actor.id, 64), name: text(body.actor.name, 200) };
}
function auditEvent(e, app, person) {
  return { app: app, auth: e.auth, requestInfo: () => e.requestInfo(), paymentActor: person || null };
}
function save(e, app, record, audit, person) {
  let before = null;
  try { before = plain(app.findRecordById(record.collection().name, record.id)); } catch (_) { /* new record */ }
  app.save(record);
  if (audit) audit(auditEvent(e, app, person), before ? "update" : "create", before, plain(record));
  return record;
}
function eventHistory(request, kind, person, details) {
  const history = array(plain(request).history);
  history.push({ at: new Date().toISOString(), action: kind, actor: person || null, details: details || {} });
  request.set("history", history);
}
function bump(request) { request.set("revision", Number(request.get("revision") || 0) + 1); }
function requestItems(app, request) {
  return array(plain(request).items).map((id) => lookup(app, ITEMS, id));
}
function snapshot(items) {
  const result = {};
  items.forEach((item) => {
    result[item.id] = {
      order: item.getString("order"), supplier: item.getString("supplier"),
      quantity: item.get("quantity"), order_qty: item.get("order_qty"), cost_price: item.get("cost_price"),
    };
  });
  return result;
}
function ensureMembership(request, items) {
  items.forEach((item) => {
    if (item.getString("payment_request") !== request.id || item.getString("payment_status") !== "required") {
      fail("This payment's items changed. Refresh the payment list and try again.");
    }
  });
}
function consistent(items, needSupplier) {
  if (!items.length) fail("A payment request must cover at least one item.", 422);
  const order = items[0].getString("order");
  const supplier = items[0].getString("supplier");
  if (!order) fail("Only customer-order items support this payment flow.", 422);
  if (needSupplier && !supplier) fail("Choose a supplier on the item before marking it paid.", 422);
  items.forEach((item) => {
    if (item.getString("order") !== order || item.getString("supplier") !== supplier) fail("Payment items must belong to the same order and supplier. Refresh the payment list before continuing.");
  });
  return { order: order, supplier: supplier };
}
function mutable(app, body) {
  const request = lookup(app, REQUESTS, body.request_id);
  if (!active(request)) fail("This request is already paid or cancelled. Refresh before continuing.");
  if (Number(body.revision) !== Number(request.get("revision"))) fail("This payment request changed. Refresh and try again.");
  return request;
}
function documentKey(doc) { return [doc.collection, doc.recordId, doc.filename, doc.role].join("|"); }
function mergeDocuments(existing, additions) {
  const result = [];
  const seen = {};
  array(existing).concat(array(additions)).forEach((doc) => {
    if (!doc || ["support", "proof"].indexOf(doc.role) === -1 || !doc.collection || !doc.recordId || !doc.filename || /[\\/]/.test(doc.filename)) fail("Invalid payment document reference.", 422);
    const normalized = { collection: text(doc.collection, 100), recordId: text(doc.recordId, 64), filename: text(doc.filename, 255), role: doc.role };
    const key = documentKey(normalized);
    if (!seen[key]) { seen[key] = true; result.push(normalized); }
  });
  return result;
}
function retiredForItem(request, item, doc) {
  if (!request) return false;
  return array(plain(request).history).some((entry) => entry.action === "routing_changed" && entry.details && entry.details.item_id === item.id &&
    array(entry.details.invalidated_documents).some((old) => documentKey(old) === documentKey(doc)));
}
function docExists(app, doc, item, candidate) {
  if (doc.collection === ITEMS && doc.recordId === item.id) {
    const source = candidate && candidate.id === item.id ? candidate : plain(item);
    return array(source.order_item_attachements).indexOf(doc.filename) !== -1;
  }
  if (doc.role === "support" && doc.collection === "purchase_orders" && doc.recordId === item.getString("purchase_order")) {
    let po;
    try { po = plain(app.findRecordById("purchase_orders", doc.recordId)); } catch (_) { return false; }
    if (po.supplier && po.supplier !== item.getString("supplier")) return false;
    return array(po.documents).concat(array(po.documents_history)).indexOf(doc.filename) !== -1;
  }
  return false;
}
/** Linked supplier PO PDFs are supporting evidence without operator selection. */
function linkedPoDocuments(app, items, request) {
  let docs = [];
  items.forEach((item) => {
    const poId = item.getString("purchase_order");
    if (!poId) return;
    let po;
    try { po = plain(app.findRecordById("purchase_orders", poId)); } catch (_) { return; }
    if (po.supplier && po.supplier !== item.getString("supplier")) return;
    const files = array(po.documents).concat(array(po.documents_history));
    const linked = files.filter((filename) => /\.pdf$/i.test(filename)).map((filename) => ({
      collection: "purchase_orders", recordId: poId, filename: filename, role: "support",
    })).filter((doc) => !retiredForItem(request, item, doc));
    docs = mergeDocuments(docs, linked);
  });
  return docs;
}
function validateAdditions(app, docs, items, request) {
  array(docs).forEach((doc) => {
    if (!items.some((item) => docExists(app, doc, item) && !retiredForItem(request, item, doc))) fail("A payment document is missing or does not belong to the selected items.", 422);
  });
}
function evidence(app, docs, items, role, candidate, request) {
  return items.every((item) => docs.some((doc) => doc.role === role && docExists(app, doc, item, candidate) && !retiredForItem(request, item, doc)));
}
function createDraft(e, app, item, person, audit, extra) {
  const request = new Record(app.findCollectionByNameOrId(REQUESTS));
  request.set("order", item.getString("order"));
  request.set("supplier", item.getString("supplier"));
  request.set("items", [item.id]);
  request.set("status", "draft");
  request.set("revision", 1);
  request.set("requested_by", person.name);
  request.set("documents", linkedPoDocuments(app, [item]));
  request.set("item_snapshot", snapshot([item]));
  eventHistory(request, "required", person, extra);
  save(e, app, request, audit, person);
  item.set("payment_status", "required");
  item.set("payment_request", request.id);
  save(e, app, item, audit, person);
  return request;
}
function requirePayment(e, app, body, person, audit) {
  const item = lookup(app, ITEMS, body.item_id);
  if (item.getString("payment_status") === "required" && item.getString("payment_request")) {
    const existing = lookup(app, REQUESTS, item.getString("payment_request"));
    if (!active(existing) || array(plain(existing).items).indexOf(item.id) === -1) fail("Payment membership needs reconciliation.");
    return existing;
  }
  if (!item.getString("order")) fail("This item has no customer order.", 422);
  if (item.getBool("ready_for_collection")) fail("Return this item to not ready for collection before requiring payment.");
  if (NEW_HOLD_STAGES.indexOf(item.getString("item_status")) === -1 || item.getString("drv_id") || item.getString("drv_status") === "assigned") fail("This item is already assigned, collected or closed; a new pre-collection payment hold cannot be added.");
  return createDraft(e, app, item, person, audit);
}
function saveRequest(e, app, body, person, audit) {
  const request = mutable(app, body);
  const items = requestItems(app, request);
  ensureMembership(request, items);
  const group = consistent(items, false);
  const docs = mergeDocuments(mergeDocuments(plain(request).documents, body.documents), linkedPoDocuments(app, items, request));
  validateAdditions(app, array(body.documents), items, request);
  request.set("order", group.order);
  request.set("supplier", group.supplier);
  request.set("documents", docs);
  request.set("item_snapshot", snapshot(items));
  request.set("status", group.supplier && evidence(app, docs, items, "support", null, request) ? "pending" : "draft");
  eventHistory(request, "documents_added", person);
  bump(request);
  return save(e, app, request, audit, person);
}
function payRequest(e, app, body, person, audit) {
  const request = mutable(app, body);
  const items = requestItems(app, request);
  ensureMembership(request, items);
  const group = consistent(items, true);
  const docs = mergeDocuments(mergeDocuments(plain(request).documents, body.documents), linkedPoDocuments(app, items, request));
  validateAdditions(app, array(body.documents), items, request);
  if (!evidence(app, docs, items, "support", null, request)) fail("Upload the supplier invoice or pro forma, or attach the supplier PO PDF, before marking paid.", 422);
  if (!evidence(app, docs, items, "proof", null, request)) fail("Upload proof of payment for every item in this request before marking paid.", 422);
  request.set("order", group.order);
  request.set("supplier", group.supplier);
  request.set("documents", docs);
  // Current revision is the stale-tab guard. The settled coverage snapshot is
  // taken now, without requiring an operator to reconfirm a separate form.
  request.set("item_snapshot", snapshot(items));
  request.set("status", "paid");
  request.set("paid_by", person.name);
  request.set("paid_at", new Date().toISOString());
  eventHistory(request, "paid", person);
  bump(request);
  save(e, app, request, audit, person);
  items.forEach((item) => {
    item.set("payment_status", "paid");
    save(e, app, item, audit, person);
  });
  return request;
}
function cancelRequest(e, app, body, person, audit) {
  const request = mutable(app, body);
  const reason = text(body.reason, 2000);
  if (!reason) fail("A reason is required to cancel a payment requirement.", 422);
  const items = requestItems(app, request);
  ensureMembership(request, items);
  const removed = body.item_id ? items.filter((item) => item.id === body.item_id) : items;
  if (!removed.length) fail("The item is not a member of this payment request.", 422);
  const remaining = items.filter((item) => removed.every((r) => r.id !== item.id));
  eventHistory(request, "cancelled", person, { reason: reason, removed_items: removed.map((item) => item.id) });
  request.set("cancellation_reason", reason);
  request.set("status", remaining.length ? "draft" : "cancelled");
  // Keep membership on cancelled requests for historical lookup.
  if (remaining.length) request.set("items", remaining.map((item) => item.id));
  request.set("item_snapshot", snapshot(remaining.length ? remaining : items));
  bump(request);
  save(e, app, request, audit, person);
  removed.forEach((item) => {
    item.set("payment_status", "");
    item.set("payment_request", "");
    save(e, app, item, audit, person);
  });
  return request;
}
function combineRequests(e, app, body, person, audit) {
  const ids = array(body.request_ids);
  if (ids.length < 2 || ids.length > 100 || ids.some((id, index) => ids.indexOf(id) !== index)) fail("Select between two and 100 distinct unpaid requests.", 422);
  const requests = ids.map((id) => mutable(app, { request_id: id, revision: body.revisions && body.revisions[id] }));
  let items = [];
  let docs = [];
  requests.forEach((request) => {
    const members = requestItems(app, request);
    ensureMembership(request, members);
    items = items.concat(members);
    docs = mergeDocuments(docs, plain(request).documents);
  });
  const group = consistent(items, true);
  const merged = new Record(app.findCollectionByNameOrId(REQUESTS));
  merged.set("order", group.order);
  merged.set("supplier", group.supplier);
  merged.set("items", items.map((item) => item.id));
  merged.set("status", "draft");
  merged.set("revision", 1);
  merged.set("requested_by", person.name);
  merged.set("documents", docs);
  merged.set("item_snapshot", snapshot(items));
  eventHistory(merged, "combined", person, { source_requests: ids });
  save(e, app, merged, audit, person);
  requests.forEach((request) => {
    request.set("status", "cancelled");
    request.set("cancellation_reason", "Combined into " + merged.id);
    eventHistory(request, "combined_into", person, { request_id: merged.id });
    bump(request);
    save(e, app, request, audit, person);
  });
  items.forEach((item) => {
    item.set("payment_request", merged.id);
    save(e, app, item, audit, person);
  });
  return merged;
}
function command(e, body, audit) {
  if (!e.auth || !e.auth.isSuperuser || !e.auth.isSuperuser()) throw new ForbiddenError("Payment commands require the WFDASH server.");
  if (!body || typeof body !== "object") fail("A payment command is required.", 422);
  const person = actor(body);
  let result;
  e.app.runInTransaction((app) => {
    assertSchema(app);
    let request;
    if (body.op === "require") request = requirePayment(e, app, body, person, audit);
    else if (body.op === "save") request = saveRequest(e, app, body, person, audit);
    else if (body.op === "paid") request = payRequest(e, app, body, person, audit);
    else if (body.op === "cancel") request = cancelRequest(e, app, body, person, audit);
    else if (body.op === "combine") request = combineRequests(e, app, body, person, audit);
    else fail("Unknown payment command.", 422);
    result = { request: plain(request) };
  });
  return result;
}
/** PB appends its ten-character suffix before the extension. */
function storedDocument(files, originalName) {
  const dot = originalName.lastIndexOf(".");
  const stem = originalName.slice(0, dot).toLowerCase();
  const extension = originalName.slice(dot).toLowerCase();
  const matches = array(files).filter((filename) => {
    const stored = String(filename).toLowerCase();
    if (stored.indexOf(stem + "_") !== 0 || stored.slice(-extension.length) !== extension) return false;
    return /^[a-z0-9]{10}$/.test(stored.slice(stem.length + 1, stored.length - extension.length));
  });
  return matches.length ? matches[matches.length - 1] : "";
}
function uploadDocument(e, body, audit) {
  if (!e.auth || !e.auth.isSuperuser || !e.auth.isSuperuser()) throw new ForbiddenError("Payment uploads require the WFDASH server.");
  const person = actor({ actor: { id: body.actor_id, name: body.actor_name } });
  const role = body.role;
  if (["support", "proof"].indexOf(role) === -1) fail("Invalid payment document role.", 422);
  const uploaded = e.findUploadedFiles("file");
  if (!uploaded || uploaded.length !== 1) fail("Upload exactly one payment document.", 422);
  const file = uploaded[0];
  if (!Number(file.size) || Number(file.size) > 20 * 1024 * 1024) fail("Choose a non-empty payment file up to 20 MB.", 422);
  const requestId = text(body.request_id, 64);
  const originalName = String(file.originalName || "");
  const prefix = "pay_" + requestId + "_" + role + "_";
  if (originalName.indexOf(prefix) !== 0 || !/^[a-f0-9]{16}\.[a-z0-9]{1,8}$/.test(originalName.slice(prefix.length))) {
    fail("Invalid payment upload identity. Refresh and retry the upload.", 422);
  }
  let result;
  e.app.runInTransaction((app) => {
    assertSchema(app);
    const request = mutable(app, { request_id: requestId, revision: body.revision });
    const items = requestItems(app, request);
    ensureMembership(request, items);
    // All capacity checks precede all writes. A concurrent upload or settlement
    // uses this same database transaction and sees committed attachment names.
    const planned = items.map((item) => {
      const current = array(plain(item).order_item_attachements);
      const existing = storedDocument(current, originalName);
      if (!existing && current.length >= 10) fail("Item " + item.id + " already has 10 attachments. Resolve capacity without removing payment history.");
      return { item: item, existing: existing };
    });
    const documents = planned.map((entry) => {
      let stored = entry.existing;
      if (!stored) {
        entry.item.set("order_item_attachements+", [file]);
        save(e, app, entry.item, audit, person);
        stored = storedDocument(plain(entry.item).order_item_attachements, originalName);
        if (!stored) fail("The payment upload could not be verified. Payment remains pending.");
      }
      return { collection: ITEMS, recordId: entry.item.id, filename: stored, role: role };
    });
    result = { documents: documents };
  });
  return result;
}
function protectProjection(info) {
  const body = info.body || {};
  if (Object.prototype.hasOwnProperty.call(body, "payment_status") || Object.prototype.hasOwnProperty.call(body, "payment_request")) {
    throw new ForbiddenError("Payment state is managed by Payments and Approvals; use its payment actions.");
  }
}
function protectPaidProofs(app, candidate) {
  if (!candidate.id) return;
  try { app.findCollectionByNameOrId(REQUESTS); } catch (_) { return; }
  const paid = app.findRecordsByFilter(REQUESTS,
    'status = "paid" && (items ?= {:item} || documents ~ {:item})', "", 0, 0, { item: candidate.id });
  const attached = array(candidate.order_item_attachements);
  paid.forEach((request) => {
    array(plain(request).documents).forEach((doc) => {
      if (doc.role === "proof" && doc.collection === ITEMS && doc.recordId === candidate.id && attached.indexOf(doc.filename) === -1) {
        fail("Historical proof of payment must remain attached to this item.");
      }
    });
  });
}
function checkReadiness(app, candidate) {
  protectPaidProofs(app, candidate);
  const state = candidate.payment_status || "";
  const requestId = candidate.payment_request || "";
  if (!state && !requestId) return;
  let request;
  try { request = app.findRecordById(REQUESTS, requestId); }
  catch (_) { fail("Payment evidence is unavailable. Reconcile the payment request before collection."); }
  const docs = array(plain(request).documents);
  if (state === "paid" && request.getString("status") === "paid" && array(plain(request).items).indexOf(candidate.id) !== -1) {
    const item = app.findRecordById(ITEMS, candidate.id);
    if (!evidence(app, docs, [item], "proof", candidate, request)) fail("Paid proof of payment must remain attached to this item.");
    const expected = (plain(request).item_snapshot || {})[candidate.id];
    if (!expected || expected.order !== candidate.order || expected.supplier !== candidate.supplier) {
      fail("The paid item's order or supplier changed. Create a fresh payment requirement before changing them.");
    }
    const preCollection = NEW_HOLD_STAGES.concat(["assigned", "ready_delivery"]);
    if (preCollection.indexOf(candidate.item_status) !== -1 || preCollection.indexOf(item.getString("item_status")) !== -1) {
      if (["order_qty", "cost_price"].some((field) => JSON.stringify(expected[field]) !== JSON.stringify(candidate[field]))) {
        fail("The paid item's supplier quantity or cost changed. Create a fresh payment requirement and reconcile it before collection.");
      }
    }
    return;
  }
  if (candidate.ready_for_collection || candidate.drv_id || ["assigned", "en_route", "collected"].indexOf(candidate.drv_status) !== -1 || BLOCKED_STAGES.indexOf(candidate.item_status) !== -1) {
    fail("Payment needed: mark the supplier payment paid with proof before this item can be ready for collection or dispatched.");
  }
}
function invalidate(e, app, item, audit, person, candidate) {
  if (item.getString("payment_status") !== "required" || !item.getString("payment_request")) return;
  const request = lookup(app, REQUESTS, item.getString("payment_request"));
  if (!active(request)) fail("Payment membership needs reconciliation.");
  const next = candidate || item;
  const routingChanged = item.getString("supplier") !== next.getString("supplier") || item.getString("order") !== next.getString("order");
  if (routingChanged) {
    const before = mergeDocuments(plain(request).documents, linkedPoDocuments(app, [item], request));
    const oldPo = item.getString("purchase_order");
    const invalidated = before.filter((doc) => (doc.collection === ITEMS && doc.recordId === item.id) || (doc.collection === "purchase_orders" && doc.recordId === oldPo));
    const otherItems = requestItems(app, request).filter((member) => member.id !== item.id);
    // Shared PO evidence may still serve another member. The per-member retired
    // association below prevents that shared reference serving the changed item.
    const remaining = array(plain(request).documents).filter((doc) => !invalidated.some((old) => documentKey(old) === documentKey(doc)) || otherItems.some((member) => docExists(app, doc, member)));
    request.set("documents", remaining);
    eventHistory(request, "routing_changed", person, {
      item_id: item.id,
      previous: { order: item.getString("order"), supplier: item.getString("supplier") },
      current: { order: next.getString("order"), supplier: next.getString("supplier") },
      invalidated_documents: invalidated,
    });
    if (array(plain(request).items).length === 1) {
      request.set("order", next.getString("order"));
      request.set("supplier", next.getString("supplier"));
    }
  } else eventHistory(request, "item_changed", person, { item_id: item.id });
  request.set("status", "draft");
  bump(request);
  save(e, app, request, audit, person);
}
function inheritSplit(e, record, audit) {
  let details = plain(record).order_item_details;
  if (typeof details === "string") { try { details = JSON.parse(details); } catch (_) { details = null; } }
  const marker = details && (details.split || details.shortCollection);
  if (!marker || !marker.sourceItemId) return;
  let source;
  try { source = e.app.findRecordById(ITEMS, marker.sourceItemId); } catch (_) { return; }
  if (source.getString("payment_status") !== "required") return;
  if (source.getString("order") !== record.getString("order")) fail("Split payment source must belong to the same order.");
  if (record.getString("payment_status") === "required") return;
  assertSchema(e.app);
  const person = { id: "", name: "Payment hold inherited from split" };
  createDraft(e, e.app, record, person, audit, { source_item_id: source.id });
  invalidate(e, e.app, source, audit, person);
}
function protectDeletion(app, record) {
  if (record.getString("payment_request") || record.getString("payment_status")) throw new ForbiddenError("Payment item history and documents cannot be deleted.");
  let collection;
  try { collection = app.findCollectionByNameOrId(REQUESTS); } catch (_) { return; }
  if (!collection) return;
  const history = app.findRecordsByFilter(REQUESTS,
    "items ?= {:item} || documents ~ {:item} || history ~ {:item}", "", 1, 0, { item: record.id });
  if (history.length) throw new ForbiddenError("This item's payment history and documents must be preserved. Cancel the item instead of deleting it.");
}
function protectModelCreate(e, audit) {
  const originalApp = e.app;
  try {
    return originalApp.runInTransaction((app) => {
      e.app = app;
      e.next();
      inheritSplit(e, e.record, audit);
      checkReadiness(app, plain(e.record));
    });
  } finally { e.app = originalApp; }
}
function protectItemUpdate(e, audit) {
  protectProjection(e.requestInfo());
  const originalApp = e.app;
  try {
    return originalApp.runInTransaction((app) => {
      e.app = app;
      const stored = app.findRecordById(ITEMS, e.record.id);
      // A read-before-payment mutation must not overwrite the newer hold.
      e.record.set("payment_status", stored.getString("payment_status"));
      e.record.set("payment_request", stored.getString("payment_request"));
      checkReadiness(app, plain(e.record));
      const watched = ["order", "supplier", "quantity", "order_qty", "cost_price"];
      const changed = watched.some((field) => JSON.stringify(stored.get(field)) !== JSON.stringify(e.record.get(field)));
      if (changed && stored.getString("payment_status") === "required") invalidate(e, app, stored, audit, null, e.record);
      return e.next();
    });
  } finally { e.app = originalApp; }
}
module.exports = { command: command, uploadDocument: uploadDocument, assertSchema: assertSchema, protectProjection: protectProjection, checkReadiness: checkReadiness, inheritSplit: inheritSplit, protectItemUpdate: protectItemUpdate, protectDeletion: protectDeletion, protectModelCreate: protectModelCreate, plain: plain };