import { db } from "@/lib/db";
import { NotificationType } from "@prisma/client";

export interface CreateNotificationPayload {
  userId: string;
  type: NotificationType;
  title: string;
  message: string;
  data?: Record<string, unknown>;
}

/**
 * Create a single in-app notification.
 */
export async function createNotification(
  payload: CreateNotificationPayload
) {
  return db.notification.create({
    data: {
      userId: payload.userId,
      type: payload.type,
      title: payload.title,
      message: payload.message,
      data: (payload.data ?? {}) as any,
    },
  });
}

/**
 * Create notifications for multiple users at once.
 */
export async function createNotifications(
  payloads: CreateNotificationPayload[]
) {
  return db.notification.createMany({
    data: payloads.map((p) => ({
      userId: p.userId,
      type: p.type,
      title: p.title,
      message: p.message,
      data: (p.data ?? {}) as any,
    })),
  });
}

/**
 * Notify all ADMIN, PRODUCER, and SUPERVISOR users about a new version upload.
 */
export async function notifyNewVersionUploaded(params: {
  shotCode: string;
  versionNumber: number;
  projectId: string;
  versionId: string;
  artistName: string;
}) {
  const staff = await db.user.findMany({
    where: {
      role: { in: ["ADMIN", "PRODUCER", "SUPERVISOR"] },
      isActive: true,
    },
    select: { id: true },
  });

  const label = `v${String(params.versionNumber).padStart(3, "0")}`;

  await createNotifications(
    staff.map((u) => ({
      userId: u.id,
      type: NotificationType.VERSION_UPLOADED,
      title: "New version uploaded",
      message: `${params.shotCode} ${label} uploaded by ${params.artistName}`,
      data: {
        versionId: params.versionId,
        shotCode: params.shotCode,
        versionNumber: params.versionNumber,
      },
    }))
  );
}

/**
 * Notify relevant users of an approval status change.
 */
export async function notifyApprovalChange(params: {
  artistId: string | null;
  shotCode: string;
  versionId: string;
  status: "APPROVED" | "REJECTED" | "NEEDS_CHANGES";
  reviewerName: string;
}) {
  if (!params.artistId) return;

  const typeMap = {
    APPROVED: NotificationType.SHOT_APPROVED,
    REJECTED: NotificationType.SHOT_REJECTED,
    NEEDS_CHANGES: NotificationType.REVISION_REQUESTED,
  } as const;

  const msgMap = {
    APPROVED: `${params.shotCode} was approved by ${params.reviewerName}`,
    REJECTED: `${params.shotCode} was rejected by ${params.reviewerName}`,
    NEEDS_CHANGES: `${params.shotCode} needs changes — ${params.reviewerName}`,
  } as const;

  await createNotification({
    userId: params.artistId,
    type: typeMap[params.status],
    title: msgMap[params.status],
    message: msgMap[params.status],
    data: { versionId: params.versionId, shotCode: params.shotCode },
  });
}

/**
 * Notify an artist that a task has been assigned to them.
 */
export async function notifyTaskAssigned(params: {
  artistId: string;
  taskTitle: string;
  taskId: string;
  contextCode: string | null;
  assignedByName: string;
}) {
  await createNotification({
    userId: params.artistId,
    type: NotificationType.TASK_ASSIGNED,
    title: "New task assigned to you",
    message: `${params.assignedByName} assigned you: ${params.taskTitle}${
      params.contextCode ? ` (${params.contextCode})` : ""
    }`,
    data: { taskId: params.taskId },
  });
}

/**
 * Notify supervisors/producers that a task is ready for internal review.
 */
export async function notifyTaskReadyForReview(params: {
  taskId: string;
  taskTitle: string;
  contextCode: string | null;
  artistName: string;
  projectId: string;
  taskUrl: string;
}) {
  const staff = await db.user.findMany({
    where: {
      role: { in: ["ADMIN", "PRODUCER", "SUPERVISOR"] },
      isActive: true,
    },
    select: { id: true },
  });

  const label = params.contextCode ? `${params.contextCode} — ` : "";
  await createNotifications(
    staff.map((u) => ({
      userId: u.id,
      type: NotificationType.TASK_READY_FOR_REVIEW,
      title: "Task ready for review",
      message: `${label}${params.taskTitle} marked ready by ${params.artistName}`,
      data: { taskId: params.taskId, taskUrl: params.taskUrl },
    }))
  );
}

/**
 * Notify an artist that a task has been approved.
 */
export async function notifyTaskApproved(params: {
  artistId: string;
  taskTitle: string;
  taskId: string;
  contextCode: string | null;
  reviewerName: string;
}) {
  await createNotification({
    userId: params.artistId,
    type: NotificationType.TASK_APPROVED,
    title: "Task approved",
    message: `${params.reviewerName} approved: ${params.taskTitle}${
      params.contextCode ? ` (${params.contextCode})` : ""
    }`,
    data: { taskId: params.taskId },
  });
}

/**
 * Notify an artist that changes were requested on their task.
 */
export async function notifyTaskChangesRequested(params: {
  artistId: string;
  taskTitle: string;
  taskId: string;
  contextCode: string | null;
  reviewerName: string;
}) {
  await createNotification({
    userId: params.artistId,
    type: NotificationType.TASK_CHANGES_REQUESTED,
    title: "Changes requested on task",
    message: `${params.reviewerName} requested changes: ${params.taskTitle}${
      params.contextCode ? ` (${params.contextCode})` : ""
    }`,
    data: { taskId: params.taskId },
  });
}

/**
 * Notify a comment author about a new reply.
 */
export async function notifyCommentReply(params: {
  commentAuthorId: string;
  replierName: string;
  shotCode: string;
  frameNumber: number;
  versionId: string;
}) {
  await createNotification({
    userId: params.commentAuthorId,
    type: NotificationType.COMMENT_REPLY,
    title: "New reply to your comment",
    message: `${params.replierName} replied on ${params.shotCode} frame ${params.frameNumber}`,
    data: {
      versionId: params.versionId,
      shotCode: params.shotCode,
      frameNumber: params.frameNumber,
    },
  });
}

/** One new comment, as the recipients of its notification need it. */
export interface NewCommentNote {
  versionId: string;
  shotCode: string;
  frameNumber: number;
  /** The shot's artist and, for a task version, the task's artist. */
  artistIds: (string | null | undefined)[];
}

/**
 * Who hears about new comments, and what they read. Pure so it can be tested:
 * every active staff member plus each note's artist, never the author.
 * Notes are grouped per version so a pasted round of client feedback is one
 * notification per shot rather than one per line.
 */
export function buildCommentNotifications(params: {
  notes: NewCommentNote[];
  authorId: string;
  authorName: string;
  /** "client" = typed on a client review link; "whatsapp" = pasted by staff. */
  origin?: "client" | "whatsapp";
  staffIds: string[];
}): CreateNotificationPayload[] {
  const byVersion = new Map<string, NewCommentNote[]>();
  for (const n of params.notes) {
    byVersion.set(n.versionId, [...(byVersion.get(n.versionId) ?? []), n]);
  }

  const who =
    params.origin === "client"
      ? `Client ${params.authorName}`
      : params.origin === "whatsapp"
        ? `Client feedback (logged by ${params.authorName})`
        : params.authorName;
  const title = params.origin ? "New client feedback" : "New feedback";

  const payloads: CreateNotificationPayload[] = [];
  for (const [versionId, notes] of byVersion) {
    const { shotCode, frameNumber } = notes[0];
    const message =
      notes.length === 1
        ? `${who} commented on ${shotCode} at frame ${frameNumber}`
        : `${who} left ${notes.length} notes on ${shotCode}`;
    const recipients = new Set([
      ...params.staffIds,
      ...notes.flatMap((n) => n.artistIds).filter((id): id is string => !!id),
    ]);
    recipients.delete(params.authorId);
    for (const userId of recipients) {
      payloads.push({
        userId,
        type: NotificationType.FEEDBACK_ADDED,
        title,
        message,
        data: { versionId, shotCode, frameNumber },
      });
    }
  }
  return payloads;
}

/**
 * Notify staff and the shot's artist about new comments. Artists who are not
 * staff are only told when they are still active.
 */
export async function notifyCommentsAdded(params: {
  notes: NewCommentNote[];
  authorId: string;
  authorName: string;
  origin?: "client" | "whatsapp";
}) {
  if (params.notes.length === 0) return;
  const artistIds = [
    ...new Set(params.notes.flatMap((n) => n.artistIds).filter((id): id is string => !!id)),
  ];
  const [staff, activeArtists] = await Promise.all([
    db.user.findMany({
      where: { role: { in: ["ADMIN", "PRODUCER", "SUPERVISOR"] }, isActive: true },
      select: { id: true },
    }),
    db.user.findMany({
      where: { id: { in: artistIds }, isActive: true, role: { not: "CLIENT" } },
      select: { id: true },
    }),
  ]);
  const active = new Set(activeArtists.map((u) => u.id));
  const payloads = buildCommentNotifications({
    ...params,
    notes: params.notes.map((n) => ({ ...n, artistIds: n.artistIds.filter((id) => id && active.has(id)) })),
    staffIds: staff.map((u) => u.id),
  });
  if (payloads.length) await createNotifications(payloads);
}