import {
  ALLOWED_COLUMNS,
  AuthorizedDIDContext,
  FindArgs,
  IAgentPlugin,
  IDataStoreORM,
  IIdentifier,
  IMessage,
  PartialIdentifier,
  TClaimsColumns,
  TCredentialColumns,
  TIdentifiersColumns,
  TMessageColumns,
  TPresentationColumns,
  UniqueVerifiableCredential,
  UniqueVerifiablePresentation,
  Where,
} from '@veramo/core-types'
import { schema } from '@veramo/core-types'
import { createMessage, Message } from './entities/message.js'
import { Claim } from './entities/claim.js'
import { Credential } from './entities/credential.js'
import { Presentation } from './entities/presentation.js'
import { Identifier } from './entities/identifier.js'
import {
  Any,
  Between,
  Brackets,
  DataSource,
  Equal,
  In,
  IsNull,
  LessThan,
  LessThanOrEqual,
  Like,
  MoreThan,
  MoreThanOrEqual,
  Not,
  SelectQueryBuilder,
} from 'typeorm'
import { getConnectedDb } from './utils.js'
import { OrPromise } from '@veramo/utils'

/**
 * This class implements the {@link @veramo/core-types#IDataStoreORM} query interface using a TypeORM compatible database.
 *
 * This allows you to filter Verifiable Credentials, Presentations and Messages by some common properties that are
 * parsed and stored in database tables.
 *
 * This class is designed to work with {@link @veramo/data-store#DataStore} which is the default way to populate the
 * database with Credentials, Presentations and Messages in such a way that they can be queried by this class.
 * These two classes MUST also share the same database connection.
 *
 * @see {@link @veramo/core-types#IDataStoreORM}
 * @see {@link @veramo/core-types#IDataStore}
 *
 * @beta This API may change without a BREAKING CHANGE notice.
 */
export class DataStoreORM implements IAgentPlugin {
  readonly methods: IDataStoreORM
  readonly schema = schema.IDataStoreORM
  private dbConnection: OrPromise<DataSource>

  constructor(dbConnection: OrPromise<DataSource>) {
    this.dbConnection = dbConnection

    this.methods = {
      dataStoreORMGetIdentifiers: this.dataStoreORMGetIdentifiers.bind(this),
      dataStoreORMGetIdentifiersCount: this.dataStoreORMGetIdentifiersCount.bind(this),
      dataStoreORMGetMessages: this.dataStoreORMGetMessages.bind(this),
      dataStoreORMGetMessagesCount: this.dataStoreORMGetMessagesCount.bind(this),
      dataStoreORMGetVerifiableCredentialsByClaims:
        this.dataStoreORMGetVerifiableCredentialsByClaims.bind(this),
      dataStoreORMGetVerifiableCredentialsByClaimsCount:
        this.dataStoreORMGetVerifiableCredentialsByClaimsCount.bind(this),
      dataStoreORMGetVerifiableCredentials: this.dataStoreORMGetVerifiableCredentials.bind(this),
      dataStoreORMGetVerifiableCredentialsCount: this.dataStoreORMGetVerifiableCredentialsCount.bind(this),
      dataStoreORMGetVerifiablePresentations: this.dataStoreORMGetVerifiablePresentations.bind(this),
      dataStoreORMGetVerifiablePresentationsCount:
        this.dataStoreORMGetVerifiablePresentationsCount.bind(this),
    }
  }

  // Identifiers

  private async identifiersQuery(
    args: FindArgs<TIdentifiersColumns>,
    context?: AuthorizedDIDContext,
  ): Promise<SelectQueryBuilder<Identifier>> {
    const where = createWhereObject(args)
    let qb = (await getConnectedDb(this.dbConnection))
      .getRepository(Identifier)
      .createQueryBuilder('identifier')
      .leftJoinAndSelect('identifier.keys', 'keys')
      .leftJoinAndSelect('identifier.services', 'services')
      .where(where)
    qb = decorateQB(qb, 'message', args)
    return qb
  }

  async dataStoreORMGetIdentifiers(
    args: FindArgs<TIdentifiersColumns>,
    context: AuthorizedDIDContext,
  ): Promise<PartialIdentifier[]> {
    const identifiers = await (await this.identifiersQuery(args)).getMany()
    return identifiers.map((i) => {
      const identifier: PartialIdentifier = i as PartialIdentifier
      if (identifier.controllerKeyId === null) {
        delete identifier.controllerKeyId
      }
      if (identifier.alias === null) {
        delete identifier.alias
      }
      if (identifier.provider === null) {
        delete identifier.provider
      }
      return identifier as IIdentifier
    })
  }

  async dataStoreORMGetIdentifiersCount(
    args: FindArgs<TIdentifiersColumns>,
    context: AuthorizedDIDContext,
  ): Promise<number> {
    return await (await this.identifiersQuery(args, context)).getCount()
  }

  // Messages

  private async messagesQuery(
    args: FindArgs<TMessageColumns>,
    context: AuthorizedDIDContext,
  ): Promise<SelectQueryBuilder<Message>> {
    const where = createWhereObject(args)
    let qb = (await getConnectedDb(this.dbConnection))
      .getRepository(Message)
      .createQueryBuilder('message')
      .leftJoinAndSelect('message.from', 'from')
      .leftJoinAndSelect('message.to', 'to')
      .leftJoinAndSelect('message.credentials', 'credentials')
      .leftJoinAndSelect('message.presentations', 'presentations')
      .where(where)
    qb = decorateQB(qb, 'message', args)
    if (context.authorizedDID) {
      qb = qb.andWhere(
        new Brackets((qb) => {
          qb.where('message.to = :ident', { ident: context.authorizedDID }).orWhere('message.from = :ident', {
            ident: context.authorizedDID,
          })
        }),
      )
    }
    return qb
  }

  async dataStoreORMGetMessages(
    args: FindArgs<TMessageColumns>,
    context: AuthorizedDIDContext,
  ): Promise<IMessage[]> {
    const messages = await (await this.messagesQuery(args, context)).getMany()
    return messages.map(createMessage)
  }

  async dataStoreORMGetMessagesCount(
    args: FindArgs<TMessageColumns>,
    context: AuthorizedDIDContext,
  ): Promise<number> {
    return (await this.messagesQuery(args, context)).getCount()
  }

  // Claims

  private async claimsQuery(
    args: FindArgs<TClaimsColumns>,
    context: AuthorizedDIDContext,
  ): Promise<SelectQueryBuilder<Claim>> {
    const where = createWhereObject(args)
    let qb = (await getConnectedDb(this.dbConnection))
      .getRepository(Claim)
      .createQueryBuilder('claim')
      .leftJoinAndSelect('claim.issuer', 'issuer')
      .leftJoinAndSelect('claim.subject', 'subject')
      .where(where)
    qb = decorateQB(qb, 'claim', args)
    qb = qb.leftJoinAndSelect('claim.credential', 'credential')
    if (context.authorizedDID) {
      qb = qb.andWhere(
        new Brackets((qb) => {
          qb.where('claim.subject = :ident', { ident: context.authorizedDID }).orWhere(
            'claim.issuer = :ident',
            {
              ident: context.authorizedDID,
            },
          )
        }),
      )
    }
    return qb
  }

  async dataStoreORMGetVerifiableCredentialsByClaims(
    args: FindArgs<TClaimsColumns>,
    context: AuthorizedDIDContext,
  ): Promise<Array<UniqueVerifiableCredential>> {
    const claims = await (await this.claimsQuery(args, context)).getMany()
    return claims
      .map((claim) => ({
        hash: claim.credential.hash,
        verifiableCredential: claim.credential.raw,
      }))
      .reduce((acc: UniqueVerifiableCredential[], current: UniqueVerifiableCredential) => {
        if (!acc.some((item) => item.hash === current.hash)) {
          acc.push(current)
        }
        return acc
      }, [])
  }

  async dataStoreORMGetVerifiableCredentialsByClaimsCount(
    args: FindArgs<TClaimsColumns>,
    context: AuthorizedDIDContext,
  ): Promise<number> {
    return (await this.claimsQuery(args, context)).getCount()
  }

  // Credentials

  private async credentialsQuery(
    args: FindArgs<TCredentialColumns>,
    context: AuthorizedDIDContext,
  ): Promise<SelectQueryBuilder<Credential>> {
    const where = createWhereObject(args)
    let qb = (await getConnectedDb(this.dbConnection))
      .getRepository(Credential)
      .createQueryBuilder('credential')
      .leftJoinAndSelect('credential.issuer', 'issuer')
      .leftJoinAndSelect('credential.subject', 'subject')
      .where(where)
    qb = decorateQB(qb, 'credential', args)
    if (context.authorizedDID) {
      qb = qb.andWhere(
        new Brackets((qb) => {
          qb.where('credential.subject = :ident', { ident: context.authorizedDID }).orWhere(
            'credential.issuer = :ident',
            {
              ident: context.authorizedDID,
            },
          )
        }),
      )
    }
    return qb
  }

  async dataStoreORMGetVerifiableCredentials(
    args: FindArgs<TCredentialColumns>,
    context: AuthorizedDIDContext,
  ): Promise<Array<UniqueVerifiableCredential>> {
    const credentials = await (await this.credentialsQuery(args, context)).getMany()
    return credentials.map((vc) => ({
      hash: vc.hash,
      verifiableCredential: vc.raw,
    }))
  }

  async dataStoreORMGetVerifiableCredentialsCount(
    args: FindArgs<TCredentialColumns>,
    context: AuthorizedDIDContext,
  ): Promise<number> {
    return (await this.credentialsQuery(args, context)).getCount()
  }

  // Presentations

  private async presentationsQuery(
    args: FindArgs<TPresentationColumns>,
    context: AuthorizedDIDContext,
  ): Promise<SelectQueryBuilder<Presentation>> {
    const where = createWhereObject(args)
    let qb = (await getConnectedDb(this.dbConnection))
      .getRepository(Presentation)
      .createQueryBuilder('presentation')
      .leftJoinAndSelect('presentation.holder', 'holder')
      .leftJoinAndSelect('presentation.verifier', 'verifier')
      .where(where)
    qb = decorateQB(qb, 'presentation', args)
    qb = addVerifierQuery(args, qb)
    if (context.authorizedDID) {
      qb = qb.andWhere(
        new Brackets((qb) => {
          qb.where('verifier.did = :ident', {
            ident: context.authorizedDID,
          }).orWhere('presentation.holder = :ident', { ident: context.authorizedDID })
        }),
      )
    }
    return qb
  }

  async dataStoreORMGetVerifiablePresentations(
    args: FindArgs<TPresentationColumns>,
    context: AuthorizedDIDContext,
  ): Promise<Array<UniqueVerifiablePresentation>> {
    const presentations = await (await this.presentationsQuery(args, context)).getMany()
    return presentations.map((vp) => ({
      hash: vp.hash,
      verifiablePresentation: vp.raw,
    }))
  }

  async dataStoreORMGetVerifiablePresentationsCount(
    args: FindArgs<TPresentationColumns>,
    context: AuthorizedDIDContext,
  ): Promise<number> {
    return (await this.presentationsQuery(args, context)).getCount()
  }
}

function opToSQL(item: Where<any>): any[] {
  switch (item.op) {
    case 'IsNull':
      return ['IS NULL', '']
    case 'Like':
      if (item.value?.length != 1) throw Error('Operation Equal requires one value')
      return ['LIKE :value', item.value[0]]
    case 'Equal':
      if (item.value?.length != 1) throw Error('Operation Equal requires one value')
      return ['= :value', item.value[0]]
    case 'Any':
    case 'Between':
    case 'LessThan':
    case 'LessThanOrEqual':
    case 'MoreThan':
    case 'MoreThanOrEqual':
      throw new Error(`${item.op} not compatible with DID argument`)
    case 'In':
    default:
      return ['IN (:...value)', item.value]
  }
}

function addVerifierQuery(input: FindArgs<any>, qb: SelectQueryBuilder<any>): SelectQueryBuilder<any> {
  if (!input) {
    return qb
  }
  if (!Array.isArray(input.where)) {
    return qb
  }
  const verifierWhere = input.where.find((item) => item.column === 'verifier')
  if (!verifierWhere) {
    return qb
  }
  const [op, value] = opToSQL(verifierWhere)
  return qb.andWhere(`verifier.did ${op}`, { value })
}

function createWhereObject(
  input: FindArgs<
    TMessageColumns | TClaimsColumns | TCredentialColumns | TPresentationColumns | TIdentifiersColumns
  >,
): any {
  const where: Record<string, any> = {}
  if (input?.where) {
    for (const item of input.where) {
      if (item.column === 'verifier') {
        continue
      }
      switch (item.op) {
        case 'Any':
          if (!Array.isArray(item.value)) throw Error('Operator Any requires value to be an array')
          where[item.column] = Any(item.value)
          break
        case 'Between':
          if (item.value?.length != 2) throw Error('Operation Between requires two values')
          where[item.column] = Between(item.value[0], item.value[1])
          break
        case 'Equal':
          if (item.value?.length != 1) throw Error('Operation Equal requires one value')
          where[item.column] = Equal(item.value[0])
          break
        case 'IsNull':
          where[item.column] = IsNull()
          break
        case 'LessThan':
          if (item.value?.length != 1) throw Error('Operation LessThan requires one value')
          where[item.column] = LessThan(item.value[0])
          break
        case 'LessThanOrEqual':
          if (item.value?.length != 1) throw Error('Operation LessThanOrEqual requires one value')
          where[item.column] = LessThanOrEqual(item.value[0])
          break
        case 'Like':
          if (item.value?.length != 1) throw Error('Operation Like requires one value')
          where[item.column] = Like(item.value[0])
          break
        case 'MoreThan':
          if (item.value?.length != 1) throw Error('Operation MoreThan requires one value')
          where[item.column] = MoreThan(item.value[0])
          break
        case 'MoreThanOrEqual':
          if (item.value?.length != 1) throw Error('Operation MoreThanOrEqual requires one value')
          where[item.column] = MoreThanOrEqual(item.value[0])
          break
        case 'In':
        default:
          if (!Array.isArray(item.value)) throw Error('Operator IN requires value to be an array')
          where[item.column] = In(item.value)
      }
      if (item.not === true) {
        where[item.column] = Not(where[item.column])
      }
    }
  }
  return where
}

function decorateQB(
  qb: SelectQueryBuilder<any>,
  tableName: string,
  input: FindArgs<any>,
): SelectQueryBuilder<any> {
  if (input?.skip) qb = qb.offset(input.skip)
  if (input?.take) qb = qb.limit(input.take)

  if (input?.order) {
    const allowedColumns = getAllowedColumnsForTable(tableName)
    for (const item of input.order) {
      if (!allowedColumns.includes(item.column)) {
        throw new Error(`Invalid column name: ${item.column}`)
      }
      qb = qb.addSelect(
        qb.connection.driver.escape(tableName) + '.' + qb.connection.driver.escape(item.column),
        item.column,
      )
      qb = qb.orderBy(qb.connection.driver.escape(item.column), item.direction)
    }
  }
  return qb
}

function getAllowedColumnsForTable(tableName: string): readonly string[] {
  return ALLOWED_COLUMNS[tableName as keyof typeof ALLOWED_COLUMNS] || []
}