// The agent and model a profile runs, which every report names.
export interface ProfileIdentity {
  type: "CLAUDE" | "CODEX" | "OPENCODE";
  model: string;
}

export interface BotProfile extends ProfileIdentity {
  token?: string;
}

// The lowercase name a profile type reads as in posted comments.
function profileName(type: ProfileIdentity["type"]): string {
  switch (type) {
    case "CLAUDE":
      return "claude";
    case "CODEX":
      return "codex";
    case "OPENCODE":
      return "opencode";
  }
}

export function profileFooter(profile: ProfileIdentity): string {
  return `> Profile: \`${profileName(profile.type)}\` · \`${profile.model}\``;
}

export function withProfile(body: string, profile: ProfileIdentity): string {
  return `${body}\n\n${profileFooter(profile)}`;
}

export type FailureReason = "SIGN_IN_FAILED" | "USAGE_EXHAUSTED" | "FAILED";

// The words a failure reason reads as in logs and posted comments.
function toMessage(reason: FailureReason): string {
  switch (reason) {
    case "SIGN_IN_FAILED":
      return "sign-in failed";
    case "USAGE_EXHAUSTED":
      return "usage exhausted";
    case "FAILED":
      return "failed";
  }
}

export interface ProfileFailure extends ProfileIdentity {
  reason: FailureReason;
}

// Where a profile's isolated user keeps its home.
interface ProfileHome {
  type: ProfileIdentity["type"];
  home: string;
}

// Raised once an agent's credentials are rejected and any re-login is spent.
export class AgentAuthError extends Error {
  constructor(message: string, options?: ErrorOptions) {
    super(message, options);
    this.name = "AgentAuthError";
  }
}

function isUsageExhausted(error: unknown): boolean {
  return /(?:usage|rate) limit|hit your (?:weekly )?limit|insufficient_quota|exceeded your current quota|too many requests|(?:api error|http error|http|status(?: code)?)[ :]+4(?:02|29)\b/iu.test(
    String(error),
  );
}

function failureReason(error: unknown): FailureReason {
  if (error instanceof AgentAuthError) {
    return "SIGN_IN_FAILED";
  }
  return isUsageExhausted(error) ? "USAGE_EXHAUSTED" : "FAILED";
}

export function failureFooter(failures: ProfileFailure[]): string {
  if (failures.length === 0) {
    return "> Profile: none";
  }
  return `> Tried: ${failures
    .map(
      ({ type, model, reason }) => `\`${profileName(type)}\` · \`${model}\` (${toMessage(reason)})`,
    )
    .join(", ")}`;
}

// Tries the profiles in order, moving on only after a sign-in failure or
// exhausted usage, and records every profile it tried.
export async function runProfiles<T, P extends ProfileIdentity>(
  profiles: P[],
  attempt: (profile: P) => Promise<T>,
  failures: ProfileFailure[] = [],
): Promise<T> {
  for (const [index, profile] of profiles.entries()) {
    try {
      return await attempt(profile);
    } catch (error) {
      const reason = failureReason(error);
      failures.push({ type: profile.type, model: profile.model, reason });
      if (reason === "FAILED" || index === profiles.length - 1) {
        throw error;
      }
      console.error(`${profile.type} ${toMessage(reason)}; trying next profile`);
    }
  }
  throw new Error("profiles must contain at least one profile");
}

// Environments are maps from variable name to value, converted to the object
// form only where a child process is spawned.
export function sanitizedEnvironment(
  environment: ReadonlyMap<string, string>,
): Map<string, string> {
  const result = new Map<string, string>();
  for (const name of [
    "PATH",
    "HOME",
    "LANG",
    "LANGUAGE",
    "LC_ALL",
    "TERM",
    "COLORTERM",
    "CI",
    "TMPDIR",
    "GITEA_TOKEN",
    "GITEA_API_URL",
    "GITEA_REPOSITORY",
    "GITHUB_WORKSPACE",
    "HTTP_PROXY",
    "HTTPS_PROXY",
    "ALL_PROXY",
    "NO_PROXY",
    "http_proxy",
    "https_proxy",
    "all_proxy",
    "no_proxy",
    "SSL_CERT_FILE",
    "SSL_CERT_DIR",
    "NODE_EXTRA_CA_CERTS",
  ]) {
    const value = environment.get(name);
    if (value !== undefined) {
      result.set(name, value);
    }
  }
  return result;
}

// The environment variable each agent CLI reads its credential from.
function tokenVariable(type: ProfileIdentity["type"]): string {
  switch (type) {
    case "CLAUDE":
      return "CLAUDE_CODE_OAUTH_TOKEN";
    case "CODEX":
      return "OPENAI_API_KEY";
    case "OPENCODE":
      return "OPENROUTER_API_KEY";
  }
}

export function agentEnvironment(
  environment: ReadonlyMap<string, string>,
  profile: ProfileHome,
  token?: string,
): Map<string, string> {
  const result = sanitizedEnvironment(environment);
  result.set("HOME", profile.home);
  if (profile.type === "CODEX") {
    result.set("CODEX_HOME", `${profile.home}/.codex`);
  }
  if (token !== undefined && token !== "") {
    const tokenName = tokenVariable(profile.type);
    result.set(tokenName, token);
  }
  return result;
}