import type {
  ChatFileAttachment as ContractChatFileAttachment,
  ChatImageAttachment as ContractChatImageAttachment,
  ChatUnknownAttachment as ContractChatUnknownAttachment,
  OrchestrationCheckpointFile,
  OrchestrationCheckpointSummary,
  OrchestrationLatestTurn,
  OrchestrationMessage,
  OrchestrationProposedPlan,
  OrchestrationSession,
  ProjectScript as ContractProjectScript,
  ProviderInteractionMode,
  RuntimeMode,
} from "@t3tools/contracts";
import type {
  EnvironmentProject,
  EnvironmentThread,
  EnvironmentThreadShell,
} from "@t3tools/client-runtime/state/shell";

export type SessionPhase = "disconnected" | "connecting" | "ready" | "running";
export const DEFAULT_RUNTIME_MODE: RuntimeMode = "full-access";

export const DEFAULT_INTERACTION_MODE: ProviderInteractionMode = "default";
export const DEFAULT_THREAD_TERMINAL_HEIGHT = 280;
export const DEFAULT_THREAD_TERMINAL_ID = "term-1";
export const MAX_TERMINALS_PER_GROUP = 4;
export type ProjectScript = ContractProjectScript;

export interface ThreadTerminalGroup {
  id: string;
  terminalIds: string[];
  splitDirection?: "horizontal" | "vertical";
}

export interface ChatImageAttachment extends ContractChatImageAttachment {
  readonly previewUrl?: string;
}

export interface ChatFileAttachment extends ContractChatFileAttachment {
  readonly previewUrl?: string;
  readonly downloadable?: boolean;
}

// Attachment types this build does not know pass through with the contract
// shape. The UI renders them as inert rows so a newer server cannot crash an
// older client.
export type ChatUnknownAttachment = ContractChatUnknownAttachment;

export type ChatAttachment = ChatImageAttachment | ChatFileAttachment | ChatUnknownAttachment;

// The union has an open member (`type: string`), so a literal comparison does
// not narrow. Use these guards wherever type-specific fields are read.
export function isImageAttachment(attachment: ChatAttachment): attachment is ChatImageAttachment {
  return attachment.type === "image";
}

export function isFileAttachment(attachment: ChatAttachment): attachment is ChatFileAttachment {
  return attachment.type === "file";
}

const VIDEO_MIME_TYPE_BY_EXTENSION: Readonly<Record<string, string>> = {
  avi: "video/x-msvideo",
  m4v: "video/mp4",
  mkv: "video/x-matroska",
  mov: "video/quicktime",
  mp4: "video/mp4",
  ogv: "video/ogg",
  webm: "video/webm",
};

export function videoMimeType(
  attachment: Pick<ChatFileAttachment, "name" | "mimeType">,
): string | null {
  const mimeType = attachment.mimeType.split(";", 1)[0]?.trim().toLowerCase() ?? "";
  if (mimeType.startsWith("video/")) return mimeType;
  const dotIndex = attachment.name.lastIndexOf(".");
  return dotIndex < 0
    ? null
    : (VIDEO_MIME_TYPE_BY_EXTENSION[attachment.name.slice(dotIndex + 1).toLowerCase()] ?? null);
}

export function isVideoAttachment(attachment: ChatFileAttachment): boolean {
  return videoMimeType(attachment) !== null;
}

export interface ChatMessage extends Omit<OrchestrationMessage, "attachments"> {
  readonly attachments?: ReadonlyArray<ChatAttachment> | undefined;
}

export type ProposedPlan = OrchestrationProposedPlan;
export type TurnDiffFileChange = OrchestrationCheckpointFile;
export type TurnDiffSummary = OrchestrationCheckpointSummary;

export type Project = EnvironmentProject;
export type Thread = EnvironmentThread;
export type ThreadShell = EnvironmentThreadShell;

export interface ThreadTurnState {
  latestTurn: OrchestrationLatestTurn | null;
}

export type SidebarThreadSummary = EnvironmentThreadShell;
export type ThreadSession = OrchestrationSession;