import { db } from "@/lib/db";
import { PipelineError } from "./errors";
import {
  matchShotCodes,
  parseShotCodes,
  resolveLineStage,
  waitingSeverity,
  type CreateRequestInput,
  type RequestLineStage,
} from "./delivery-request-state";

/**
 * Delivery requests: what a client asked for, held open until it has gone out.
 *
 * A request stores only the ask and its shot list. Whether each shot has been
 * delivered is read from the packages and manual deliveries themselves, so a
 * request cannot say "done" when the delivery record does not.
 */

export async function createDeliveryRequest(input: CreateRequestInput, userId: string) {
  const project = await db.project.findUnique({ where: { id: input.projectId }, select: { id: true } });
  if (!project) throw new PipelineError(404, "Project not found");

  const select = { id: true, shotCode: true, clientCode: true } as const;
  let shots: { id: string; shotCode: string; clientCode: string | null }[];

  if (input.episode) {
    // Snapshot: the request is for the shots in the episode today. A shot
    // added to the episode later is a new ask, not a silent change to this one.
    shots = await db.shot.findMany({ where: { projectId: project.id, episode: input.episode }, select });
    if (!shots.length) throw new PipelineError(422, `No shots in episode ${input.episode}`);
  } else if (input.shotIds) {
    const ids = [...new Set(input.shotIds)];
    shots = await db.shot.findMany({ where: { projectId: project.id, id: { in: ids } }, select });
    if (shots.length !== ids.length) {
      throw new PipelineError(422, "Some of the selected shots are not in this project");
    }
  } else {
    const codes = parseShotCodes(input.shotCodes ?? "");
    const all = await db.shot.findMany({ where: { projectId: project.id }, select });
    const { matched, unmatched } = matchShotCodes(codes, all);
    if (unmatched.length) {
      throw new PipelineError(
        422,
        `${unmatched.length} code${unmatched.length === 1 ? "" : "s"} did not match a shot: ${unmatched.slice(0, 10).join(", ")}${unmatched.length > 10 ? "…" : ""}`,
        { unmatched }
      );
    }
    shots = matched;
    if (!shots.length) throw new PipelineError(422, "No shot codes found in the text");
  }

  return db.$transaction(async (tx) => {
    const last = await tx.deliveryRequest.aggregate({
      where: { projectId: project.id },
      _max: { requestNumber: true },
    });
    const request = await tx.deliveryRequest.create({
      data: {
        projectId: project.id,
        requestNumber: (last._max.requestNumber ?? 0) + 1,
        episode: input.episode ?? "",
        deliverable: input.deliverable,
        requestedBy: input.requestedBy,
        note: input.note || null,
        // Noon UTC so the calendar day survives any timezone it is shown in.
        dueDate: input.dueDate ? new Date(`${input.dueDate}T12:00:00.000Z`) : null,
        createdById: userId,
        lines: {
          create: shots.map((s) => ({ shotId: s.id, shotCode: s.shotCode, clientCode: s.clientCode })),
        },
      },
    });
    return { request: { id: request.id, requestNumber: request.requestNumber, lineCount: shots.length } };
  });
}

export async function cancelDeliveryRequest(requestId: string, reason: string, userId: string) {
  const request = await db.deliveryRequest.findUnique({ where: { id: requestId } });
  if (!request) throw new PipelineError(404, "Delivery request not found");
  if (request.cancelledAt) return { request: { id: request.id }, alreadyApplied: true };
  await db.deliveryRequest.update({
    where: { id: request.id },
    data: { cancelledAt: new Date(), cancelledById: userId, cancelReason: reason },
  });
  return { request: { id: request.id }, alreadyApplied: false };
}

export interface DeliveryRequestLineView {
  id: string;
  shotId: string;
  shotCode: string;
  clientCode: string | null;
  stage: RequestLineStage;
  /** The export to package when the stage is READY. */
  readyExportId: string | null;
}

export interface DeliveryRequestView {
  id: string;
  requestNumber: number;
  projectId: string;
  projectCode: string;
  episode: string;
  deliverable: string;
  requestedBy: string;
  note: string | null;
  dueDate: Date | null;
  createdAt: Date;
  cancelledAt: Date | null;
  cancelReason: string | null;
  state: "OPEN" | "CLOSED" | "CANCELLED";
  lineCount: number;
  deliveredCount: number;
  severity: "normal" | "warning" | "critical";
  lines: DeliveryRequestLineView[];
}

/**
 * Requests with each line's stage worked out from the delivery record.
 * `openOnly` is what the dashboard wants; the deliveries page takes the recent
 * history too.
 */
export async function listDeliveryRequests(
  filter: { projectId?: string; openOnly?: boolean } = {}
): Promise<DeliveryRequestView[]> {
  const requests = await db.deliveryRequest.findMany({
    where: {
      ...(filter.projectId ? { projectId: filter.projectId } : {}),
      ...(filter.openOnly ? { cancelledAt: null } : {}),
      project: { status: { in: ["ACTIVE", "ON_HOLD"] } },
    },
    orderBy: { createdAt: "desc" },
    take: 200,
    include: {
      project: { select: { code: true } },
      lines: { orderBy: { shotCode: "asc" } },
    },
  });
  if (!requests.length) return [];

  const shotIds = [...new Set(requests.flatMap((r) => r.lines.map((l) => l.shotId)))];
  const [items, shots, exports] = await Promise.all([
    db.deliveryItem.findMany({
      where: {
        shotId: { in: shotIds },
        package: { kind: "EXR_DELIVERY", status: { in: ["QUEUED", "BUILDING", "READY", "DELIVERED"] } },
      },
      select: { shotId: true, package: { select: { status: true, uploadedAt: true, deliveredAt: true } } },
    }),
    db.shot.findMany({
      where: { id: { in: shotIds } },
      select: { id: true, manualDeliveredAt: true, manualDeliveryUrl: true, manualDeliverySharedWith: true },
    }),
    db.export.findMany({
      where: { shotId: { in: shotIds }, status: { in: ["READY_FOR_DELIVERY", "READY_FOR_QC"] } },
      orderBy: { versionNumber: "desc" },
      select: { id: true, shotId: true, status: true },
    }),
  ]);

  const packagesByShot = new Map<string, (typeof items)[number]["package"][]>();
  for (const item of items) {
    if (!packagesByShot.has(item.shotId)) packagesByShot.set(item.shotId, []);
    packagesByShot.get(item.shotId)!.push(item.package);
  }
  const shotById = new Map(shots.map((s) => [s.id, s]));
  const exportsByShot = new Map<string, typeof exports>();
  for (const row of exports) {
    if (!exportsByShot.has(row.shotId)) exportsByShot.set(row.shotId, []);
    exportsByShot.get(row.shotId)!.push(row);
  }

  const views = requests.map((request): DeliveryRequestView => {
    const lines = request.lines.map((line): DeliveryRequestLineView => {
      const shot = shotById.get(line.shotId);
      const shotExports = exportsByShot.get(line.shotId) ?? [];
      const stage = resolveLineStage({
        requestCreatedAt: request.createdAt,
        packages: packagesByShot.get(line.shotId) ?? [],
        manual: {
          deliveredAt: shot?.manualDeliveredAt ?? null,
          url: shot?.manualDeliveryUrl ?? null,
          sharedWith: shot?.manualDeliverySharedWith ?? null,
        },
        exportStatuses: shotExports.map((e) => e.status),
      });
      return {
        id: line.id,
        shotId: line.shotId,
        shotCode: line.shotCode,
        clientCode: line.clientCode,
        stage,
        // Newest first, so this is the version a build would take.
        readyExportId:
          stage === "READY" ? (shotExports.find((e) => e.status === "READY_FOR_DELIVERY")?.id ?? null) : null,
      };
    });
    const deliveredCount = lines.filter((l) => l.stage === "DELIVERED").length;
    const state = request.cancelledAt ? "CANCELLED" : deliveredCount === lines.length ? "CLOSED" : "OPEN";
    return {
      id: request.id,
      requestNumber: request.requestNumber,
      projectId: request.projectId,
      projectCode: request.project.code,
      episode: request.episode,
      deliverable: request.deliverable,
      requestedBy: request.requestedBy,
      note: request.note,
      dueDate: request.dueDate,
      createdAt: request.createdAt,
      cancelledAt: request.cancelledAt,
      cancelReason: request.cancelReason,
      state,
      lineCount: lines.length,
      deliveredCount,
      severity: state === "OPEN" ? waitingSeverity(request.createdAt, request.dueDate) : "normal",
      lines,
    };
  });

  return filter.openOnly ? views.filter((v) => v.state === "OPEN") : views;
}

/** Episodes a request can be logged against, with how many shots each holds. */
export async function getRequestOptions(projectId: string) {
  const groups = await db.shot.groupBy({
    by: ["episode"],
    where: { projectId, episode: { not: null } },
    _count: { _all: true },
  });
  return {
    episodes: groups
      .filter((g) => g.episode)
      .map((g) => ({ episode: g.episode as string, shotCount: g._count._all }))
      .sort((a, b) => a.episode.localeCompare(b.episode)),
  };
}

/**
 * How many of these shots are still owed on a request. A manual delivery of
 * such a shot has to carry the upload link and recipient, or the request it
 * answers would stay open with nothing to say why.
 */
export async function countShotsOnOpenRequests(shotIds: string[]): Promise<number> {
  if (!shotIds.length) return 0;
  const open = await listDeliveryRequests({ openOnly: true });
  const wanted = new Set(shotIds);
  const owed = new Set<string>();
  for (const request of open) {
    for (const line of request.lines) {
      if (line.stage !== "DELIVERED" && wanted.has(line.shotId)) owed.add(line.shotId);
    }
  }
  return owed.size;
}