import { Readable } from "node:stream";

import type { CaseFile } from "@prisma/client";

import {
  MINIO_BUCKET_NAME,
  MINIO_PUBLIC_BASE_URL,
} from "@/lib/constants";
import { assertCaseFileWithinSizeLimit, getSafeMimeType, isAllowedCaseFileType } from "@/lib/file-utils";
import { trimOrUndefined } from "@/lib/utils";
import { requireCaseByIdForOwner } from "@/server/cases/service";
import { requireCustomerByIdForOwner } from "@/server/customers/service";
import { db } from "@/server/db";
import { AppError } from "@/server/errors";
import { buildCaseFileStorageKey, ensureMinioBucket, minioClient } from "@/server/storage/minio";
import type {
  CaseFileListQueryInput,
  CaseFileMetadataInput,
} from "@/server/validation/case";
import type { CaseFileRagStatusValue } from "@/lib/constants";

export function normalizeCaseFileListFilters(input: CaseFileListQueryInput) {
  return {
    search: trimOrUndefined(input.fileSearch),
    selectedFileId: trimOrUndefined(input.fileId),
    sessionPreset: input.sessionPreset,
  };
}

export async function listCaseFilesForOwner(
  ownerId: string,
  customerId: string,
  caseId: string,
  search?: string,
) {
  await requireCaseByIdForOwner(ownerId, customerId, caseId);

  return db.caseFile.findMany({
    where: {
      ownerId,
      customerId,
      caseId,
      ...(search
        ? {
            displayName: {
              contains: search,
              mode: "insensitive",
            },
          }
        : {}),
    },
    orderBy: {
      createdAt: "desc",
    },
  });
}

export async function listCustomerArchiveFilesForOwner(
  ownerId: string,
  customerId: string,
  search?: string,
) {
  await requireCustomerByIdForOwner(customerId, ownerId);

  return db.caseFile.findMany({
    where: {
      ownerId,
      customerId,
      ...(search
        ? {
            displayName: {
              contains: search,
              mode: "insensitive",
            },
          }
        : {}),
    },
    include: {
      case: true,
    },
    orderBy: {
      createdAt: "desc",
    },
  });
}

export async function getCaseFileByIdForOwner(
  ownerId: string,
  customerId: string,
  caseId: string,
  fileId: string,
) {
  return db.caseFile.findFirst({
    where: {
      id: fileId,
      ownerId,
      customerId,
      caseId,
    },
    include: {
      case: {
        include: {
          customer: true,
        },
      },
    },
  });
}

export async function requireCaseFileByIdForOwner(
  ownerId: string,
  customerId: string,
  caseId: string,
  fileId: string,
) {
  const file = await getCaseFileByIdForOwner(ownerId, customerId, caseId, fileId);

  if (!file) {
    throw new AppError("الملف ده مش موجود.", 404);
  }

  return file;
}

export async function uploadCaseFileForOwner(
  ownerId: string,
  customerId: string,
  caseId: string,
  metadata: CaseFileMetadataInput,
  uploadedFile: File,
) {
  await requireCaseByIdForOwner(ownerId, customerId, caseId);

  if (!uploadedFile || uploadedFile.size <= 0) {
    throw new AppError("اختار ملف قبل الرفع.", 400);
  }

  if (!assertCaseFileWithinSizeLimit(uploadedFile.size)) {
    throw new AppError("حجم الملف أكبر من الحد المسموح 25 ميجابايت.", 400);
  }

  const mimeType = getSafeMimeType(uploadedFile.name, uploadedFile.type);

  if (!isAllowedCaseFileType(uploadedFile.name, mimeType)) {
    throw new AppError("نوع الملف ده غير مدعوم في النسخة الحالية.", 400);
  }

  const arrayBuffer = await uploadedFile.arrayBuffer();
  const buffer = Buffer.from(arrayBuffer);
  const storageKey = buildCaseFileStorageKey(caseId, uploadedFile.name);
  const ragStatus: CaseFileRagStatusValue =
    mimeType === "application/pdf" ? "PROCESSING" : "SKIPPED";

  await ensureMinioBucket();
  await minioClient.putObject(MINIO_BUCKET_NAME, storageKey, buffer, buffer.length, {
    "Content-Type": mimeType,
  });

  return db.caseFile.create({
    data: {
      ownerId,
      customerId,
      caseId,
      displayName: metadata.displayName.trim(),
      description: trimOrUndefined(metadata.description),
      originalFileName: uploadedFile.name,
      mimeType,
      sizeBytes: uploadedFile.size,
      storageBucket: MINIO_BUCKET_NAME,
      storageKey,
      ragStatus,
    },
  });
}

export async function updateCaseFileRagStatus(
  fileId: string,
  status: CaseFileRagStatusValue,
  options?: {
    error?: string | null;
    syncedAt?: Date | null;
  },
) {
  return db.caseFile.update({
    where: {
      id: fileId,
    },
    data: {
      ragStatus: status,
      ragError: options?.error ?? null,
      ragSyncedAt: options?.syncedAt ?? null,
    },
  });
}

export async function listReadyPdfFilesForCase(
  ownerId: string,
  customerId: string,
  caseId: string,
) {
  await requireCaseByIdForOwner(ownerId, customerId, caseId);

  return db.caseFile.findMany({
    where: {
      ownerId,
      customerId,
      caseId,
      mimeType: "application/pdf",
      ragStatus: "READY",
    },
    orderBy: {
      createdAt: "desc",
    },
  });
}

export async function getCaseFileContentStream(file: CaseFile) {
  const stream = await minioClient.getObject(file.storageBucket, file.storageKey);
  return Readable.toWeb(stream) as ReadableStream<Uint8Array>;
}

export function buildCaseFileContentUrl(params: {
  customerId: string;
  caseId: string;
  fileId: string;
  download?: boolean;
}) {
  const basePath = `/api/customers/${params.customerId}/cases/${params.caseId}/files/${params.fileId}/content`;
  return params.download ? `${basePath}?download=1` : basePath;
}

export function buildCaseFilePreviewUrl(params: {
  customerId: string;
  caseId: string;
  fileId: string;
}) {
  const path = buildCaseFileContentUrl(params);

  if (!MINIO_PUBLIC_BASE_URL) {
    return path;
  }

  const normalizedBase = MINIO_PUBLIC_BASE_URL.replace(/\/$/, "");
  return `${normalizedBase}${path}`;
}

export function buildInlineFileName(file: Pick<CaseFile, "displayName" | "originalFileName">) {
  const extension = file.originalFileName.includes(".")
    ? file.originalFileName.slice(file.originalFileName.lastIndexOf("."))
    : "";

  if (extension && file.displayName.toLowerCase().endsWith(extension.toLowerCase())) {
    return file.displayName;
  }

  return `${file.displayName}${extension}`;
}