import "server-only";

import { DeleteObjectCommand, PutObjectCommand, S3Client } from "@aws-sdk/client-s3";
import { put } from "@vercel/blob";
import {
  getDefaultStorageConfig,
  getStorageConfigById,
  getSystemSetting,
} from "@/lib/db/queries";
import {
  enqueueStorageMigrationTask,
  getPreferredAliyunStorageConfig,
  isAliyunStorageConfig,
} from "@/lib/storage/migration-db";
import {
  defaultOssImageMigrationConfig,
  normalizeOssImageMigrationConfig,
  OSS_MIGRATION_CONFIG_KEY,
  type OssImageMigrationConfig,
} from "@/lib/storage/migration-config";
import type { StorageConfig } from "@/lib/db/schema";

export type S3UploadConfig = {
  endpoint: string;
  region: string;
  bucket: string;
  accessKeyId: string;
  secretAccessKey: string;
  publicUrl?: string;
};

let lastKnownGoodDbS3Config: S3UploadConfig | null = null;
const STORAGE_FAILOVER_CONFIG_KEY = "storage_failover_config";

function normalizeEndpoint(endpoint: string): string {
  const trimmed = endpoint.trim().replace(/\/+$/, "");
  if (!trimmed) return "";

  // 阿里云 OSS 统一强制 HTTPS，避免误填 http 或带空格导致连接失败
  if (/aliyuncs\.com/i.test(trimmed)) {
    const withoutProtocol = trimmed.replace(/^https?:\/\//i, "");
    return `https://${withoutProtocol}`;
  }

  return trimmed;
}

function normalizePublicUrl(publicUrl?: string): string | undefined {
  if (!publicUrl) return undefined;
  const trimmed = publicUrl.trim().replace(/\/+$/, "");
  return trimmed || undefined;
}

// 获取文件的 Content-Type
function getContentType(filename: string): string {
  const ext = filename.toLowerCase().split(".").pop();
  const types: Record<string, string> = {
    jpg: "image/jpeg",
    jpeg: "image/jpeg",
    png: "image/png",
    gif: "image/gif",
    webp: "image/webp",
    svg: "image/svg+xml",
    pdf: "application/pdf",
    json: "application/json",
    txt: "text/plain",
    html: "text/html",
    css: "text/css",
    js: "application/javascript",
  };
  return types[ext ?? ""] ?? "application/octet-stream";
}

function createS3Client(config: S3UploadConfig): S3Client {
  const normalizedEndpoint = normalizeEndpoint(config.endpoint);
  const lowerEndpoint = normalizedEndpoint.toLowerCase();
  const isCloudS3 =
    lowerEndpoint.includes("aliyuncs.com") ||
    lowerEndpoint.includes("amazonaws.com");

  return new S3Client({
    endpoint: normalizedEndpoint,
    region: config.region || "auto",
    credentials: {
      accessKeyId: config.accessKeyId,
      secretAccessKey: config.secretAccessKey,
    },
    forcePathStyle: !isCloudS3,
  });
}

// S3/MinIO 上传函数（使用 AWS SDK）
async function uploadToS3(
  filename: string,
  buffer: ArrayBuffer,
  config: S3UploadConfig
) {
  const {
    endpoint,
    region,
    bucket,
    accessKeyId,
    secretAccessKey,
    publicUrl,
  } = config;
  const normalizedEndpoint = normalizeEndpoint(endpoint);
  const normalizedPublicUrl = normalizePublicUrl(publicUrl);

  // 生成唯一的文件名
  const timestamp = Date.now();
  const randomString = Math.random().toString(36).slice(2, 8);
  const ext = filename.split(".").pop();
  const key = `uploads/${timestamp}-${randomString}.${ext}`;

  const contentType = getContentType(filename);

  try {
    const s3Client = createS3Client({
      endpoint: normalizedEndpoint,
      region,
      bucket,
      accessKeyId,
      secretAccessKey,
      publicUrl: normalizedPublicUrl,
    });

    console.log(`[S3 Upload] Uploading to: ${normalizedEndpoint}/${bucket}/${key}`);

    // 上传文件
    const command = new PutObjectCommand({
      Bucket: bucket,
      Key: key,
      Body: Buffer.from(buffer),
      ContentType: contentType,
      // 设置为公开可读（如果您的 MinIO 桶支持）
      ACL: "public-read",
    });

    await s3Client.send(command);

    console.log(`[S3 Upload] Upload successful: ${key}`);

    // 返回文件的公开 URL
    // MinIO 的公开 URL 格式通常是: http://endpoint:port/bucket/key
    let fileUrl: string;
    if (normalizedPublicUrl) {
      // 如果用户配置了自定义公开 URL，使用它
      fileUrl = `${normalizedPublicUrl}/${key}`;
    } else {
      // 否则使用 endpoint + bucket + key
      fileUrl = `${normalizedEndpoint}/${bucket}/${key}`;
    }

    console.log(`[S3 Upload] File URL: ${fileUrl}`);

    return {
      url: fileUrl,
      pathname: key,
      contentType,
    };
  } catch (error) {
    console.error("[S3 Upload] Error:", error);
    throw error;
  }
}

export async function uploadFileWithS3Config(
  filename: string,
  buffer: ArrayBuffer,
  config: S3UploadConfig
) {
  return uploadToS3(filename, buffer, config);
}

export async function deleteS3ObjectByPath(pathname: string, config: S3UploadConfig) {
  const key = String(pathname || "").replace(/^\/+/, "");
  if (!key) return;

  const s3Client = createS3Client(config);
  await s3Client.send(
    new DeleteObjectCommand({
      Bucket: config.bucket,
      Key: key,
    })
  );
}

export function toDbS3UploadConfig(raw: unknown): S3UploadConfig | null {
  const value = raw as Record<string, unknown> | null | undefined;
  const endpoint = value?.endpoint ? normalizeEndpoint(String(value.endpoint)) : "";
  const bucket = value?.bucket ? String(value.bucket).trim() : "";
  const accessKeyId = value?.accessKeyId ? String(value.accessKeyId).trim() : "";
  const secretAccessKey = value?.secretAccessKey
    ? String(value.secretAccessKey).trim()
    : "";

  if (
    !value ||
    value.type !== "s3" ||
    !value.isEnabled ||
    !endpoint ||
    !bucket ||
    !accessKeyId ||
    !secretAccessKey
  ) {
    return null;
  }

  return {
    endpoint,
    region: String(value.region || "auto").trim() || "auto",
    bucket,
    accessKeyId,
    secretAccessKey,
    publicUrl: normalizePublicUrl(value.publicUrl ? String(value.publicUrl) : undefined),
  };
}

function buildEnvS3Config(): S3UploadConfig | null {
  const endpoint = process.env.S3_ENDPOINT
    ? normalizeEndpoint(process.env.S3_ENDPOINT)
    : "";
  const bucket = process.env.S3_BUCKET?.trim() ?? "";
  const accessKeyId = process.env.S3_ACCESS_KEY_ID?.trim() ?? "";
  const secretAccessKey = process.env.S3_SECRET_ACCESS_KEY?.trim() ?? "";

  if (endpoint && bucket && accessKeyId && secretAccessKey) {
    return {
      endpoint,
      region: process.env.S3_REGION?.trim() || "auto",
      bucket,
      accessKeyId,
      secretAccessKey,
      publicUrl: normalizePublicUrl(process.env.S3_PUBLIC_URL),
    };
  }
  return null;
}

function normalizeStorageFailoverConfig(value: unknown): {
  enabled: boolean;
  backupStorageConfigId: string;
} {
  const raw =
    value && typeof value === "object" && !Array.isArray(value)
      ? (value as Record<string, unknown>)
      : {};
  return {
    enabled: raw.enabled === true,
    backupStorageConfigId: String(raw.backupStorageConfigId || "").trim(),
  };
}

async function resolvePreferredUploadStorageConfig(
  migrationConfig: OssImageMigrationConfig
): Promise<StorageConfig | undefined> {
  if (!migrationConfig.enabled || !migrationConfig.preferAliyunForUploads) {
    return await getDefaultStorageConfig();
  }

  const preferredAliyunConfig = await getPreferredAliyunStorageConfig({
    preferredId: migrationConfig.sourceStorageConfigId || undefined,
  });

  if (preferredAliyunConfig) {
    return preferredAliyunConfig;
  }

  return await getDefaultStorageConfig();
}

async function maybeEnqueueAliyunMigrationTask(params: {
  uploaded: { url: string; pathname: string };
  storageConfig?: StorageConfig;
  migrationConfig: OssImageMigrationConfig;
}) {
  const { uploaded, storageConfig, migrationConfig } = params;
  if (!migrationConfig.enabled) return;
  if (!storageConfig || !isAliyunStorageConfig(storageConfig)) return;
  if (!uploaded.url || !uploaded.pathname) return;

  const targetStorageConfig =
    (migrationConfig.targetStorageConfigId
      ? await getStorageConfigById({ id: migrationConfig.targetStorageConfigId }).catch(() => undefined)
      : undefined) || (await getDefaultStorageConfig().catch(() => undefined));

  if (!targetStorageConfig) return;
  if (targetStorageConfig.id === storageConfig.id) return;
  if (isAliyunStorageConfig(targetStorageConfig)) return;
  if (!toDbS3UploadConfig(targetStorageConfig)) return;

  const now = Date.now();
  const migrateAfterAt = new Date(
    now + migrationConfig.migrateAfterHours * 60 * 60 * 1000
  );
  const cleanupAfterAt = new Date(
    now + migrationConfig.cleanupAfterHours * 60 * 60 * 1000
  );

  await enqueueStorageMigrationTask({
    sourceUrl: uploaded.url,
    sourcePath: uploaded.pathname,
    sourceStorageConfigId: storageConfig.id,
    migrateAfterAt,
    cleanupAfterAt,
  });
}

async function uploadWithBackupStorageConfig(
  filename: string,
  buffer: ArrayBuffer,
  primaryStorageConfigId?: string
): Promise<
  | {
      uploaded: { url: string; pathname: string; contentType: string };
      storageConfig?: StorageConfig;
    }
  | null
> {
  try {
    const setting = await getSystemSetting({ key: STORAGE_FAILOVER_CONFIG_KEY });
    const failover = normalizeStorageFailoverConfig(setting?.value);

    if (!failover.enabled || !failover.backupStorageConfigId) {
      return null;
    }

    if (
      primaryStorageConfigId &&
      failover.backupStorageConfigId === primaryStorageConfigId
    ) {
      console.warn(
        "[Upload] Backup storage config equals default storage config, skipping failover retry"
      );
      return null;
    }

    const backupStorageConfig = await getStorageConfigById({
      id: failover.backupStorageConfigId,
    });
    const backupS3Config = toDbS3UploadConfig(backupStorageConfig);

    if (!backupS3Config) {
      console.warn(
        "[Upload] Backup storage config is invalid, disabled, or not S3 compatible"
      );
      return null;
    }

    console.log(
      `[Upload] Retrying with backup S3 config: ${backupStorageConfig?.name ?? failover.backupStorageConfigId}`
    );

    const uploaded = await uploadToS3(filename, buffer, backupS3Config);
    lastKnownGoodDbS3Config = backupS3Config;
    return {
      uploaded,
      storageConfig: backupStorageConfig,
    };
  } catch (error) {
    console.error("[Upload] Backup storage config retry failed:", error);
    return null;
  }
}

// 上传文件到存储服务
export async function uploadFile(
  filename: string,
  buffer: ArrayBuffer
): Promise<{ url: string; pathname: string; contentType: string }> {
  console.log(`[Upload] Starting upload for file: ${filename}`);

  let dbS3Config: S3UploadConfig | null = null;
  let primaryStorageConfigId: string | undefined;
  let selectedStorageConfig: StorageConfig | undefined;
  let migrationConfig = defaultOssImageMigrationConfig;
  try {
    const migrationSetting = await getSystemSetting({
      key: OSS_MIGRATION_CONFIG_KEY,
    }).catch(() => undefined);
    migrationConfig = normalizeOssImageMigrationConfig(migrationSetting?.value);

    selectedStorageConfig = await resolvePreferredUploadStorageConfig(migrationConfig);
    primaryStorageConfigId = selectedStorageConfig?.id;
    dbS3Config = toDbS3UploadConfig(selectedStorageConfig);
    if (dbS3Config) {
      console.log(`[Upload] Using database S3 config: ${selectedStorageConfig?.name}`);
      console.log(`[Upload] Endpoint: ${dbS3Config.endpoint}`);
      console.log(`[Upload] Bucket: ${dbS3Config.bucket}`);
      const uploaded = await uploadToS3(filename, buffer, dbS3Config);
      lastKnownGoodDbS3Config = dbS3Config;
      await maybeEnqueueAliyunMigrationTask({
        uploaded,
        storageConfig: selectedStorageConfig,
        migrationConfig,
      }).catch((error) => {
        console.error("[Upload] Failed to enqueue OSS migration task:", error);
      });
      return uploaded;
    }
    console.warn("[Upload] No valid S3 config in database");
  } catch (error) {
    console.error("[Upload] Database storage path failed:", error);

    const uploadedFromBackup = await uploadWithBackupStorageConfig(
      filename,
      buffer,
      primaryStorageConfigId
    );
    if (uploadedFromBackup) {
      await maybeEnqueueAliyunMigrationTask({
        uploaded: uploadedFromBackup.uploaded,
        storageConfig: uploadedFromBackup.storageConfig,
        migrationConfig,
      }).catch((enqueueError) => {
        console.error("[Upload] Failed to enqueue backup OSS migration task:", enqueueError);
      });
      return uploadedFromBackup.uploaded;
    }

    if (lastKnownGoodDbS3Config) {
      try {
        console.log("[Upload] Retrying with last known good database S3 config");
        return await uploadToS3(filename, buffer, lastKnownGoodDbS3Config);
      } catch (retryError) {
        console.error("[Upload] Last known S3 config upload failed:", retryError);
      }
    }
  }

  if (!dbS3Config) {
    const uploadedFromBackup = await uploadWithBackupStorageConfig(
      filename,
      buffer,
      primaryStorageConfigId
    );
    if (uploadedFromBackup) {
      await maybeEnqueueAliyunMigrationTask({
        uploaded: uploadedFromBackup.uploaded,
        storageConfig: uploadedFromBackup.storageConfig,
        migrationConfig,
      }).catch((enqueueError) => {
        console.error("[Upload] Failed to enqueue backup OSS migration task:", enqueueError);
      });
      return uploadedFromBackup.uploaded;
    }
  }

  const envS3Config = buildEnvS3Config();
  if (envS3Config) {
    console.log("[Upload] Using environment variable S3 config");
    return await uploadToS3(filename, buffer, envS3Config);
  }

  if (!process.env.BLOB_READ_WRITE_TOKEN) {
    throw new Error(
      "No available storage backend: database S3 failed, env S3 missing, and BLOB_READ_WRITE_TOKEN is not configured."
    );
  }

  // 最终回退到 Vercel Blob
  console.log("[Upload] Falling back to Vercel Blob");
  const data = await put(filename, buffer, {
    access: "public",
  });

  return {
    url: data.url,
    pathname: data.pathname,
    contentType: getContentType(filename),
  };
}

// 获取当前使用的存储类型
export async function getStorageType(): Promise<
  "database-s3" | "env-s3" | "vercel-blob"
> {
  try {
    const storageConfig = await getDefaultStorageConfig();
    if (
      storageConfig &&
      storageConfig.type === "s3" &&
      storageConfig.endpoint &&
      storageConfig.bucket
    ) {
      return "database-s3";
    }
  } catch (error) {
    // ignore
  }

  if (process.env.S3_ENDPOINT && process.env.S3_BUCKET) {
    return "env-s3";
  }

  return "vercel-blob";
}