const API_CONFIG = {
  local: {
    http: "http://localhost:8080",
    ws: "ws://localhost:8080",
  },
  production: {
    http: "https://api.makima.jp",
    ws: "wss://api.makima.jp",
  },
} as const;

type Environment = "local" | "production";

function detectEnvironment(): Environment {
  // Check if explicitly set via env var
  const envOverride = import.meta.env.VITE_API_ENV as Environment | undefined;
  if (envOverride && (envOverride === "local" || envOverride === "production")) {
    return envOverride;
  }

  // Auto-detect based on hostname
  if (typeof window !== "undefined") {
    const hostname = window.location.hostname;
    if (hostname === "localhost" || hostname === "127.0.0.1") {
      return "local";
    }
  }

  return "production";
}

const env = detectEnvironment();

export const API_BASE = API_CONFIG[env].http;
export const WS_BASE = API_CONFIG[env].ws;
export const LISTEN_ENDPOINT = `${WS_BASE}/api/v1/listen`;
export const FILE_SUBSCRIBE_ENDPOINT = `${WS_BASE}/api/v1/files/subscribe`;

export function getEnvironment(): Environment {
  return env;
}

// File API types
export interface TranscriptEntry {
  id: string;
  speaker: string;
  start: number;
  end: number;
  text: string;
  isFinal: boolean;
}

// Chart types for visualization
export type ChartType = "line" | "bar" | "pie" | "area";

// Body element types for structured content
export type BodyElement =
  | { type: "heading"; level: number; text: string }
  | { type: "paragraph"; text: string }
  | {
      type: "chart";
      chartType: ChartType;
      title?: string;
      data: Record<string, unknown>[];
      config?: Record<string, unknown>;
    }
  | { type: "image"; src: string; alt?: string; caption?: string };

export interface FileSummary {
  id: string;
  name: string;
  description: string | null;
  transcriptCount: number;
  duration: number | null;
  version: number;
  createdAt: string;
  updatedAt: string;
}

export interface FileDetail {
  id: string;
  ownerId: string;
  name: string;
  description: string | null;
  transcript: TranscriptEntry[];
  location: string | null;
  summary: string | null;
  body: BodyElement[];
  version: number;
  createdAt: string;
  updatedAt: string;
}

export interface FileListResponse {
  files: FileSummary[];
  total: number;
}

export interface CreateFileRequest {
  name?: string;
  description?: string;
  transcript: TranscriptEntry[];
  location?: string;
}

export interface UpdateFileRequest {
  name?: string;
  description?: string;
  transcript?: TranscriptEntry[];
  summary?: string;
  body?: BodyElement[];
  version?: number;
}

// Conflict error types
export interface ConflictErrorResponse {
  code: "VERSION_CONFLICT";
  message: string;
  expectedVersion: number;
  actualVersion: number;
}

export class VersionConflictError extends Error {
  expectedVersion: number;
  actualVersion: number;

  constructor(conflict: ConflictErrorResponse) {
    super(conflict.message);
    this.name = "VersionConflictError";
    this.expectedVersion = conflict.expectedVersion;
    this.actualVersion = conflict.actualVersion;
  }
}

// Available LLM models
export type LlmModel = "claude-sonnet" | "claude-opus" | "groq";

// Chat API types
export interface ChatMessage {
  role: "user" | "assistant";
  content: string;
}

export interface ChatRequest {
  message: string;
  model?: LlmModel;
  history?: ChatMessage[];
}

export interface ToolCallInfo {
  name: string;
  result: {
    success: boolean;
    message: string;
  };
}

// User question types for interactive LLM tool
export interface UserQuestion {
  id: string;
  question: string;
  options: string[];
  allowMultiple: boolean;
  allowCustom: boolean;
}

export interface UserAnswer {
  id: string;
  answers: string[];
}

export interface ChatResponse {
  response: string;
  toolCalls: ToolCallInfo[];
  updatedBody: BodyElement[];
  updatedSummary: string | null;
  pendingQuestions?: UserQuestion[];
}

// File API functions
export async function listFiles(): Promise<FileListResponse> {
  const res = await fetch(`${API_BASE}/api/v1/files`);
  if (!res.ok) {
    throw new Error(`Failed to list files: ${res.statusText}`);
  }
  return res.json();
}

export async function getFile(id: string): Promise<FileDetail> {
  const res = await fetch(`${API_BASE}/api/v1/files/${id}`);
  if (!res.ok) {
    throw new Error(`Failed to get file: ${res.statusText}`);
  }
  return res.json();
}

export async function createFile(data: CreateFileRequest): Promise<FileDetail> {
  const res = await fetch(`${API_BASE}/api/v1/files`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify(data),
  });
  if (!res.ok) {
    throw new Error(`Failed to create file: ${res.statusText}`);
  }
  return res.json();
}

export async function updateFile(
  id: string,
  data: UpdateFileRequest
): Promise<FileDetail> {
  const res = await fetch(`${API_BASE}/api/v1/files/${id}`, {
    method: "PUT",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify(data),
  });

  if (res.status === 409) {
    const conflict = (await res.json()) as ConflictErrorResponse;
    throw new VersionConflictError(conflict);
  }

  if (!res.ok) {
    throw new Error(`Failed to update file: ${res.statusText}`);
  }
  return res.json();
}

export async function deleteFile(id: string): Promise<void> {
  const res = await fetch(`${API_BASE}/api/v1/files/${id}`, {
    method: "DELETE",
  });
  if (!res.ok) {
    throw new Error(`Failed to delete file: ${res.statusText}`);
  }
}

// Chat API function
export async function chatWithFile(
  id: string,
  message: string,
  model?: LlmModel,
  history?: ChatMessage[]
): Promise<ChatResponse> {
  const body: ChatRequest = { message };
  if (model) {
    body.model = model;
  }
  if (history && history.length > 0) {
    body.history = history;
  }
  const res = await fetch(`${API_BASE}/api/v1/files/${id}/chat`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify(body),
  });
  if (!res.ok) {
    const errorText = await res.text();
    throw new Error(`Chat failed: ${errorText || res.statusText}`);
  }
  return res.json();
}

// Version history types
export type VersionSource = "user" | "llm" | "system";

export interface FileVersion {
  version: number;
  name: string;
  description: string | null;
  summary: string | null;
  body: BodyElement[];
  source: VersionSource;
  createdAt: string;
  changeDescription?: string;
}

export interface FileVersionSummary {
  version: number;
  source: VersionSource;
  createdAt: string;
  changeDescription?: string;
}

export interface FileVersionListResponse {
  versions: FileVersionSummary[];
  total: number;
}

export interface RestoreVersionRequest {
  targetVersion: number;
}

// Version history API functions
export async function listFileVersions(fileId: string): Promise<FileVersionListResponse> {
  const res = await fetch(`${API_BASE}/api/v1/files/${fileId}/versions`);
  if (!res.ok) {
    throw new Error(`Failed to list versions: ${res.statusText}`);
  }
  return res.json();
}

export async function getFileVersion(fileId: string, version: number): Promise<FileVersion> {
  const res = await fetch(`${API_BASE}/api/v1/files/${fileId}/versions/${version}`);
  if (!res.ok) {
    throw new Error(`Failed to get version: ${res.statusText}`);
  }
  return res.json();
}

export async function restoreFileVersion(
  fileId: string,
  targetVersion: number,
  currentVersion: number
): Promise<FileDetail> {
  const res = await fetch(`${API_BASE}/api/v1/files/${fileId}/versions/restore`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ targetVersion, currentVersion }),
  });

  if (res.status === 409) {
    const conflict = (await res.json()) as ConflictErrorResponse;
    throw new VersionConflictError(conflict);
  }

  if (!res.ok) {
    throw new Error(`Failed to restore version: ${res.statusText}`);
  }
  return res.json();
}

// =============================================================================
// LLM Tool Definitions for Version History
// =============================================================================
// These types define the tools available to the LLM for version history access.
// The backend should implement handlers for these tools.

/**
 * Tool: read_version
 * Allows the LLM to read the content of a specific historical version.
 * This is read-only - it does not modify the document.
 */
export interface ReadVersionToolInput {
  version: number;
}

export interface ReadVersionToolOutput {
  success: boolean;
  version: number;
  body: BodyElement[];
  summary: string | null;
  source: VersionSource;
  createdAt: string;
  changeDescription?: string;
  message: string;
}

/**
 * Tool: list_versions
 * Allows the LLM to list all available versions of the document.
 */
export interface ListVersionsToolOutput {
  success: boolean;
  versions: FileVersionSummary[];
  currentVersion: number;
  message: string;
}

/**
 * Tool: restore_version
 * Allows the LLM to restore the document to a specific historical version.
 * This creates a new version with the content from the target version.
 */
export interface RestoreVersionToolInput {
  targetVersion: number;
  reason?: string;
}

export interface RestoreVersionToolOutput {
  success: boolean;
  previousVersion: number;
  newVersion: number;
  restoredFromVersion: number;
  message: string;
}

// LLM Tool type definitions for the backend
export type LlmVersionTool =
  | { name: "read_version"; input: ReadVersionToolInput }
  | { name: "list_versions"; input: Record<string, never> }
  | { name: "restore_version"; input: RestoreVersionToolInput };

export type LlmVersionToolResult =
  | { name: "read_version"; result: ReadVersionToolOutput }
  | { name: "list_versions"; result: ListVersionsToolOutput }
  | { name: "restore_version"; result: RestoreVersionToolOutput };