import { and, desc, eq, sql } from "drizzle-orm";
import { randomUUID } from "crypto";
import { sshCredentials, sshCredentialUsage } from "../db/schema.js";
import type { DatabaseContext } from "./database-context.js";
import { DataCrypto } from "../../utils/data-crypto.js";
import { rowsAffected } from "./mutation-result.js";
import {
  deleteReturning,
  insertReturning,
  updateReturning,
} from "./returning.js";

export type CredentialRecord = typeof sshCredentials.$inferSelect;
export type NewCredentialRecord = typeof sshCredentials.$inferInsert;
export type CredentialUpdate = Partial<
  Omit<NewCredentialRecord, "id" | "userId">
>;

export class CredentialRepository {
  constructor(
    private readonly context: DatabaseContext,
    private readonly onWrite?: () => void | Promise<void>,
  ) {}

  async create(credential: NewCredentialRecord): Promise<CredentialRecord> {
    const rows = await insertReturning(this.context, sshCredentials, {
      syncId: randomUUID(),
      ...credential,
    });
    await this.afterWrite();
    return rows[0];
  }

  async createEncryptedForUser(
    userId: string,
    credential: NewCredentialRecord | Record<string, unknown>,
  ): Promise<CredentialRecord> {
    const userDataKey = DataCrypto.validateUserAccess(userId);
    const tempId = credential.id ?? Date.now();
    const dataWithTempId = {
      syncId: randomUUID(),
      ...credential,
      id: tempId,
    };
    const encryptedCredential = this.encryptCredentialRecordForWrite(
      dataWithTempId,
      userId,
      userDataKey,
    );

    if (!credential.id) {
      delete (encryptedCredential as Partial<NewCredentialRecord>).id;
    }

    const rows = await insertReturning(
      this.context,
      sshCredentials,
      encryptedCredential as NewCredentialRecord,
    );

    await this.afterWrite();
    return DataCrypto.decryptRecord(
      "ssh_credentials",
      rows[0],
      userId,
      userDataKey,
    );
  }

  async findByIdForUser(
    userId: string,
    credentialId: number,
  ): Promise<CredentialRecord | null> {
    const rows = await this.context.drizzle
      .select()
      .from(sshCredentials)
      .where(
        and(
          eq(sshCredentials.id, credentialId),
          eq(sshCredentials.userId, userId),
        ),
      )
      .limit(1);

    return rows[0] ?? null;
  }

  async findById(credentialId: number): Promise<CredentialRecord | null> {
    const rows = await this.context.drizzle
      .select()
      .from(sshCredentials)
      .where(eq(sshCredentials.id, credentialId))
      .limit(1);

    return rows[0] ?? null;
  }

  async listByUserId(userId: string): Promise<CredentialRecord[]> {
    return this.context.drizzle
      .select()
      .from(sshCredentials)
      .where(eq(sshCredentials.userId, userId))
      .orderBy(desc(sshCredentials.updatedAt));
  }

  async existsForImportIdentity(
    userId: string,
    name: string,
    username: string | null,
  ): Promise<boolean> {
    const rows = await this.context.drizzle
      .select({ id: sshCredentials.id })
      .from(sshCredentials)
      .where(
        and(
          eq(sshCredentials.userId, userId),
          eq(sshCredentials.name, name),
          eq(sshCredentials.username, username),
        ),
      )
      .limit(1);

    return rows.length > 0;
  }

  async findDecryptedByIdForUser(
    userId: string,
    credentialId: number,
  ): Promise<CredentialRecord | null> {
    const row = await this.findByIdForUser(userId, credentialId);
    return this.decryptOne(row, userId);
  }

  async listDecryptedByUserId(userId: string): Promise<CredentialRecord[]> {
    const rows = await this.listByUserId(userId);
    return this.decryptMany(rows, userId);
  }

  async listFolders(userId: string): Promise<string[]> {
    const rows = await this.context.drizzle
      .select({ folder: sshCredentials.folder })
      .from(sshCredentials)
      .where(eq(sshCredentials.userId, userId));

    return [...new Set(rows.map((row) => row.folder).filter(Boolean))].sort();
  }

  async renameFolder(
    userId: string,
    oldName: string,
    newName: string,
  ): Promise<number> {
    const result = await this.context.drizzle
      .update(sshCredentials)
      .set({ folder: newName, updatedAt: sql`CURRENT_TIMESTAMP` })
      .where(
        and(
          eq(sshCredentials.userId, userId),
          eq(sshCredentials.folder, oldName),
        ),
      );

    if (rowsAffected(result) > 0) {
      await this.afterWrite();
    }

    return rowsAffected(result);
  }

  async updateForUser(
    userId: string,
    credentialId: number,
    update: CredentialUpdate,
  ): Promise<CredentialRecord | null> {
    const rows = await updateReturning(
      this.context,
      sshCredentials,
      { ...update, updatedAt: sql`CURRENT_TIMESTAMP` },
      and(
        eq(sshCredentials.id, credentialId),
        eq(sshCredentials.userId, userId),
      ),
    );

    await this.afterWrite();
    return rows[0] ?? null;
  }

  async updateEncryptedForUser(
    userId: string,
    credentialId: number,
    update: CredentialUpdate,
  ): Promise<CredentialRecord | null> {
    const userDataKey = DataCrypto.validateUserAccess(userId);
    const encryptedUpdate = this.encryptCredentialRecordForWrite(
      update,
      userId,
      userDataKey,
    );

    const rows = await updateReturning(
      this.context,
      sshCredentials,
      { ...encryptedUpdate, updatedAt: sql`CURRENT_TIMESTAMP` },
      and(
        eq(sshCredentials.id, credentialId),
        eq(sshCredentials.userId, userId),
      ),
    );

    await this.afterWrite();
    return this.decryptOne(rows[0] ?? null, userId);
  }

  /**
   * Manual drag-to-reorder write path. Updates sortOrder for each id one row
   * at a time inside a transaction rather than a single set-for-all-matching
   * -ids statement, matching HostRepository.reorderForUser.
   */
  async reorderForUser(
    userId: string,
    positions: { id: number; sortOrder: number }[],
  ): Promise<number> {
    if (positions.length === 0) return 0;

    let affected: number;
    if (this.context.dialect === "sqlite") {
      affected = this.context.drizzle.transaction((tx) => {
        let count = 0;
        for (const { id, sortOrder } of positions) {
          const result = tx
            .update(sshCredentials)
            .set({ sortOrder, updatedAt: sql`CURRENT_TIMESTAMP` })
            .where(
              and(eq(sshCredentials.id, id), eq(sshCredentials.userId, userId)),
            )
            .run();
          count += rowsAffected(result);
        }
        return count;
      });
    } else {
      affected = await this.context.drizzle.transaction(async (tx) => {
        let count = 0;
        for (const { id, sortOrder } of positions) {
          const result = await tx
            .update(sshCredentials)
            .set({ sortOrder, updatedAt: sql`CURRENT_TIMESTAMP` })
            .where(
              and(eq(sshCredentials.id, id), eq(sshCredentials.userId, userId)),
            );
          count += rowsAffected(result);
        }
        return count;
      });
    }

    if (affected > 0) {
      await this.afterWrite();
    }

    return affected;
  }

  async deleteForUser(
    userId: string,
    credentialId: number,
  ): Promise<{ syncId: string | null } | null> {
    const rows = await deleteReturning(
      this.context,
      sshCredentials,
      and(
        eq(sshCredentials.id, credentialId),
        eq(sshCredentials.userId, userId),
      ),
    );

    await this.afterWrite();
    return rows[0] ? { syncId: rows[0].syncId } : null;
  }

  async deleteByUserId(userId: string): Promise<number> {
    const result = await this.context.drizzle
      .delete(sshCredentials)
      .where(eq(sshCredentials.userId, userId));

    if (rowsAffected(result) > 0) {
      await this.afterWrite();
    }

    return rowsAffected(result);
  }

  async recordUsage(
    userId: string,
    credentialId: number,
    hostId: number,
    usedAt = new Date().toISOString(),
  ): Promise<void> {
    await this.context.drizzle.insert(sshCredentialUsage).values({
      credentialId,
      hostId,
      userId,
      usedAt,
    });

    await this.context.drizzle
      .update(sshCredentials)
      .set({
        lastUsed: usedAt,
        usageCount: sql`${sshCredentials.usageCount} + 1`,
      })
      .where(
        and(
          eq(sshCredentials.id, credentialId),
          eq(sshCredentials.userId, userId),
        ),
      );
    await this.afterWrite();
  }

  private decryptOne<T extends Record<string, unknown>>(
    record: T | null,
    userId: string,
  ): T | null {
    if (!record) return null;
    const userDataKey = DataCrypto.getUserDataKey(userId);
    if (!userDataKey) return null;
    return DataCrypto.decryptRecord(
      "ssh_credentials",
      record,
      userId,
      userDataKey,
    );
  }

  private decryptMany<T extends Record<string, unknown>>(
    records: T[],
    userId: string,
  ): T[] {
    const userDataKey = DataCrypto.getUserDataKey(userId);
    if (!userDataKey) return [];
    return DataCrypto.decryptRecords(
      "ssh_credentials",
      records,
      userId,
      userDataKey,
    );
  }

  /**
   * Re-keys every credential of one user to another: decrypt under the old
   * owner's key, encrypt under the new one, change the owner. Used when an
   * account is deleted and its data is inherited rather than dropped.
   */
  async transferAllToUser(
    fromUserId: string,
    toUserId: string,
  ): Promise<number[]> {
    const fromKey = DataCrypto.validateUserAccess(fromUserId);
    const toKey = DataCrypto.validateUserAccess(toUserId);
    const rows = await this.context.drizzle
      .select()
      .from(sshCredentials)
      .where(eq(sshCredentials.userId, fromUserId));
    const moved: number[] = [];
    for (const row of rows) {
      const plain = DataCrypto.decryptRecord(
        "ssh_credentials",
        row,
        fromUserId,
        fromKey,
      );
      const {
        id: _id,
        userId: _userId,
        ...fields
      } = plain as Record<string, unknown>;
      const encrypted = DataCrypto.encryptRecord(
        "ssh_credentials",
        { ...fields, id: row.id },
        toUserId,
        toKey,
      ) as Record<string, unknown>;
      delete encrypted.id;
      await this.context.drizzle
        .update(sshCredentials)
        .set({
          ...(encrypted as Partial<NewCredentialRecord>),
          userId: toUserId,
        })
        .where(eq(sshCredentials.id, row.id));
      moved.push(row.id);
    }
    if (moved.length) await this.afterWrite();
    return moved;
  }

  private encryptCredentialRecordForWrite<T extends Record<string, unknown>>(
    record: T,
    userId: string,
    userDataKey: Buffer,
  ): T {
    return DataCrypto.encryptRecord(
      "ssh_credentials",
      record,
      userId,
      userDataKey,
    );
  }

  private async afterWrite(): Promise<void> {
    await this.onWrite?.();
  }
}