import { apiFetch } from "./client";
import { getLocale } from "../i18n";
import {
  captureAuthOperation,
  isAuthOperationCurrent,
  requireAuthOperationPrecondition,
  type AuthOperationPrecondition,
} from "../auth/authOperation";
import { getSettings } from "./settings";
import { listWorkspaces } from "./workspaces";
import {
  WORKSPACE_POLICY_ERROR, WORKSPACE_SUMMARY_ERROR, WorkspaceSelectionError, workspacePolicyGate,
  workspacePreferences, type WorkspacePreference,
} from "../workspaces/drafts";
import type {
  AuthenticatedUser, ResumeSessionResult, SessionScope, SessionSummary, SessionDocument, UiResponse,
} from "./types";

type NewSessionInput = { question: string; name?: string } & Partial<WorkspacePreference>;

async function selectedPreferences(precondition?: AuthOperationPrecondition): Promise<WorkspacePreference> {
  requireAuthOperationPrecondition(precondition);
  const saved = workspacePreferences.load();
  if (saved.workspaceId && saved.provider && saved.model && saved.thinking) return saved;

  // A direct new-session entry point can run before the composer has mounted. Seed current
  // application memory from the installation defaults once, then keep choices ephemeral.
  const legacy = await getSettings();
  requireAuthOperationPrecondition(precondition);
  const latest = workspacePreferences.load();
  return workspacePreferences.save({
    workspaceId: latest.workspaceId ?? legacy.workspace,
    provider: latest.provider ?? legacy.provider,
    model: latest.model ?? legacy.model,
    thinking: latest.thinking ?? legacy.thinking,
  });
}

async function ensureWorkspaceSelectionPolicy(precondition?: AuthOperationPrecondition): Promise<WorkspacePreference> {
  while (true) {
    requireAuthOperationPrecondition(precondition);
    const preferences = workspacePreferences.load();
    const workspaceId = preferences.workspaceId;
    if (!workspaceId) return preferences;
    workspacePolicyGate.beginSummary(workspaceId);
    let workspaces: Awaited<ReturnType<typeof listWorkspaces>>;
    try {
      workspaces = await listWorkspaces();
    } catch {
      requireAuthOperationPrecondition(precondition);
      if (workspacePreferences.load().workspaceId !== workspaceId) continue;
      workspacePolicyGate.rejectSummary(workspaceId);
      throw new WorkspaceSelectionError(WORKSPACE_SUMMARY_ERROR);
    }
    requireAuthOperationPrecondition(precondition);
    if (workspacePreferences.load().workspaceId !== workspaceId) continue;
    const workspace = workspaces.find((candidate) => candidate.id === workspaceId);
    if (!workspace) {
      if (workspaces.length === 0) {
        workspacePolicyGate.allowLegacy(workspaceId);
        return workspacePreferences.load();
      }
      let installationDefault: string | undefined;
      try {
        installationDefault = (await getSettings()).workspace;
      } catch {
        requireAuthOperationPrecondition(precondition);
        if (workspacePreferences.load().workspaceId !== workspaceId) continue;
        workspacePolicyGate.rejectSummary(workspaceId);
        throw new WorkspaceSelectionError(WORKSPACE_SUMMARY_ERROR);
      }
      requireAuthOperationPrecondition(precondition);
      if (workspacePreferences.load().workspaceId !== workspaceId) continue;
      const replacement = workspaces.find(
        (candidate) => candidate.id === installationDefault && candidate.revision,
      ) ?? workspaces.find((candidate) => candidate.revision);
      if (!replacement) {
        requireAuthOperationPrecondition(precondition);
        workspacePolicyGate.reject(workspaceId);
        throw new WorkspaceSelectionError(WORKSPACE_POLICY_ERROR);
      }
      requireAuthOperationPrecondition(precondition);
      workspacePreferences.save({ ...preferences, workspaceId: replacement.id });
      continue;
    }
    if (!workspace.revision) {
      workspacePolicyGate.reject(workspaceId);
      throw new WorkspaceSelectionError(WORKSPACE_POLICY_ERROR);
    }
    workspacePolicyGate.select(workspaceId);
    workspacePolicyGate.resolve(workspaceId);
    return workspacePreferences.load();
  }
}

export async function createSession(i: NewSessionInput, precondition?: AuthOperationPrecondition) {
  const interactionLanguage = getLocale();
  const initiatingOperation = captureAuthOperation();
  const effectivePrecondition = precondition ?? (initiatingOperation ? {
    operation: initiatingOperation,
    isCurrent: () => isAuthOperationCurrent(initiatingOperation, {
      sessionId: null,
      disposalEpoch: initiatingOperation.disposalEpoch,
    }),
  } : undefined);
  requireAuthOperationPrecondition(effectivePrecondition);
  await selectedPreferences(effectivePrecondition);
  requireAuthOperationPrecondition(effectivePrecondition);
  const selection = await ensureWorkspaceSelectionPolicy(effectivePrecondition);
  requireAuthOperationPrecondition(effectivePrecondition);
  return apiFetch<{ id: string }>("/sessions", {
    method: "POST",
    body: JSON.stringify({ ...i, ...selection, interactionLanguage }),
  });
}

/** Best-effort warm-up; callers must not await it before showing the composer. */
export const prewarmRuntime = () =>
  apiFetch<void>("/runtime/prewarm", { method: "POST" });

/** Compatibility export for existing shell tests/callers; AuthGate uses the validated auth API. */
export const getMe = () => apiFetch<AuthenticatedUser>("/me");

export const listSessions = (scope: SessionScope = "mine") =>
  apiFetch<SessionSummary[]>(`/sessions?scope=${scope}`);

// eslint-disable-next-line @typescript-eslint/no-explicit-any
export const getSession = (id: string) => apiFetch<any>(`/sessions/${id}`);

export const postResponse = (id: string, uiResponse: UiResponse) =>
  apiFetch<void>(`/sessions/${id}/response`, {
    method: "POST",
    body: JSON.stringify({ ui_response: uiResponse }),
  });

export const postSteer = (id: string, text: string) =>
  apiFetch<void>(`/sessions/${id}/steer`, {
    method: "POST",
    body: JSON.stringify({ text }),
  });

export const closeSession = (id: string) =>
  apiFetch<void>(`/sessions/${id}/close`, { method: "POST" });

export async function resumeSession(id: string) {
  const operation = captureAuthOperation();
  const precondition = operation ? {
    operation,
    isCurrent: () => isAuthOperationCurrent(operation, { sessionId: null, disposalEpoch: operation.disposalEpoch }),
  } : undefined;
  const selected = await selectedPreferences(precondition);
  requireAuthOperationPrecondition(precondition);
  return apiFetch<ResumeSessionResult>(`/sessions/${id}/resume`, {
    method: "POST",
    // The workspace is owned by the persisted session, never by this request.
    body: JSON.stringify({ provider: selected.provider, model: selected.model }),
  });
}

export const renameSession = (id: string, name: string) =>
  apiFetch<void>(`/sessions/${id}/rename`, { method: "POST", body: JSON.stringify({ name }) });

export const setSessionGroup = (id: string, group: string) =>
  apiFetch<void>(`/sessions/${id}/group`, { method: "POST", body: JSON.stringify({ group }) });

export const archiveSession = (id: string) =>
  apiFetch<void>(`/sessions/${id}/archive`, { method: "POST" });

export const unarchiveSession = (id: string) =>
  apiFetch<void>(`/sessions/${id}/unarchive`, { method: "POST" });

export const deleteSession = (id: string) =>
  apiFetch<void>(`/sessions/${id}`, { method: "DELETE" });

export const getSessionDocuments = (id: string) =>
  apiFetch<SessionDocument[]>(`/sessions/${id}/documents`);

export async function checkDwhHealth(): Promise<{ ok: boolean }> {
  const timeout = new Promise<{ ok: false }>((r) => setTimeout(() => r({ ok: false }), 5000));
  try {
    return await Promise.race([
      apiFetch<{ ok: boolean; detail: string }>("/health/dwh"),
      timeout,
    ]);
  } catch {
    return { ok: false };
  }
}