// Copyright 2016 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

import Foundation

public enum SyncbaseError: ErrorType, CustomStringConvertible {
  case AlreadyConfigured
  case NotConfigured
  case NotLoggedIn
  case NotAuthorized
  case NotInDevMode
  case UnknownBatch
  case NotBoundToBatch
  case ReadOnlyBatch
  case ConcurrentBatch
  case BlobNotCommitted
  case SyncgroupJoinFailed
  case BadExecStreamHeader
  case InvalidPermissionsChange
  case Exist
  case NoExist
  case InvalidName(name: String)
  case CorruptDatabase(path: String)
  case InvalidOperation(reason: String)
  case InvalidUTF8(invalidUtf8: String)
  case CastError(obj: Any)
  case IllegalArgument(detail: String)
  case NoAccess(detail: String)
  case UnknownVError(err: VError)

  init(_ err: VError) {
    // TODO(zinman): Make VError better by having the proper arguments transmitted across
    // so we don't have to use err.msg to repeat our messages.
    switch err.id {
    case "v.io/v23/services/syncbase.NotInDevMode": self = SyncbaseError.NotInDevMode
    case "v.io/v23/services/syncbase.InvalidName": self = SyncbaseError.InvalidName(name: err.msg)
    case "v.io/v23/services/syncbase.CorruptDatabase": self = SyncbaseError.CorruptDatabase(path: err.msg)
    case "v.io/v23/services/syncbase.UnknownBatch": self = SyncbaseError.UnknownBatch
    case "v.io/v23/services/syncbase.NotBoundToBatch": self = SyncbaseError.NotBoundToBatch
    case "v.io/v23/services/syncbase.ReadOnlyBatch": self = SyncbaseError.ReadOnlyBatch
    case "v.io/v23/services/syncbase.ConcurrentBatch": self = SyncbaseError.ConcurrentBatch
    case "v.io/v23/services/syncbase.BlobNotCommitted": self = SyncbaseError.BlobNotCommitted
    case "v.io/v23/services/syncbase.SyncgroupJoinFailed": self = SyncbaseError.SyncgroupJoinFailed
    case "v.io/v23/services/syncbase.BadExecStreamHeader": self = SyncbaseError.BadExecStreamHeader
    case "v.io/v23/services/syncbase.InvalidPermissionsChange": self = SyncbaseError.InvalidPermissionsChange
    case "v.io/v23/verror.Exist": self = SyncbaseError.Exist
    case "v.io/v23/verror.NoExist": self = SyncbaseError.NoExist
    case "v.io/v23/verror.NoAccess": self = SyncbaseError.NoAccess(detail: err.msg)
    default: self = SyncbaseError.UnknownVError(err: err)
    }
  }

  public var description: String {
    switch (self) {
    case .AlreadyConfigured: return "Already configured"
    case .NotConfigured: return "Not configured (via Syncbase.configure)"
    case .NotLoggedIn: return "Not logged in (via Syncbase.login)"
    case .NotAuthorized: return "No valid blessings; create new blessings using oauth"
    case .NotInDevMode: return "Not running with --dev=true"
    case .UnknownBatch: return "Unknown batch, perhaps the server restarted"
    case .NotBoundToBatch: return "Not bound to batch"
    case .ReadOnlyBatch: return "Batch is read-only"
    case .ConcurrentBatch: return "Concurrent batch"
    case .BlobNotCommitted: return "Blob is not yet committed"
    case .SyncgroupJoinFailed: return "Syncgroup join failed"
    case .BadExecStreamHeader: return "Exec stream header improperly formatted"
    case .InvalidPermissionsChange: return "The sequence of permission changes is invalid"
    case .NoExist: return "Does not exist"
    case .Exist: return "Already exists"
    case .InvalidName(let name): return "Invalid name: \(name)"
    case .CorruptDatabase(let path):
      return "Database corrupt, moved to path \(path); client must create a new database"
    case .InvalidOperation(let reason): return "Invalid operation: \(reason)"
    case .InvalidUTF8(let invalidUtf8): return "Unable to convert to UTF-8: \(invalidUtf8)"
    case .CastError(let obj): return "Unable to convert to cast: \(obj)"
    case .IllegalArgument(let detail): return "Illegal argument: \(detail)"
    case .NoAccess(let detail): return "Access Denied: \(detail)"
    case .UnknownVError(let err): return "Unknown error: \(err)"
    }
  }
}