import {
  resolveAgentModelSelection,
  type AgentModelPreset,
  type ExternalAgentConfig,
} from '../infrastructure/ai/types';
import { getExternalAgentSdkBackend } from '../infrastructure/ai/managedAgents';
import { canonicalizeEffortEncodedModelId } from '../infrastructure/ai/composerPicker';

export { canonicalizeEffortEncodedModelId };

export type SdkRuntimeModelCatalog = {
  currentModelId: string | null;
  models: AgentModelPreset[];
};

export type SdkRuntimeModelCacheEntry = SdkRuntimeModelCatalog & {
  updatedAt: number;
};

type SdkRuntimeModelCacheOptions = {
  ttlMs?: number;
  maxEntries?: number;
  now?: () => number;
};

type SdkRuntimeModelRefreshOptions = {
  force?: boolean;
};

const SDK_RUNTIME_MODEL_CACHE_TTL_MS = 5 * 60 * 1000;
const SDK_RUNTIME_MODEL_CACHE_MAX_ENTRIES = 64;
// Keep in sync with main-process SDK_MODEL_CACHE_ENV_KEYS: profile-affecting
// env must bust the renderer cache so we re-query after OpenCode config switches.
const MODEL_CACHE_ENV_HINTS = [
  'HOME',
  'USERPROFILE',
  'XDG_CONFIG_HOME',
  'OPENCODE_BIN',
  'OPENCODE_CONFIG',
  'OPENCODE_CONFIG_DIR',
  'OPENCODE_CONFIG_CONTENT',
  'CLAUDE_CODE_EXECUTABLE',
  'CODEBUDDY_CODE_PATH',
  'CURSOR_API_KEY',
  'NETCATTY_CURSOR_AUTH_MODE',
  'NETCATTY_CURSOR_CLI_BIN',
] as const;

function cloneCatalog(catalog: SdkRuntimeModelCatalog): SdkRuntimeModelCatalog {
  return {
    currentModelId: catalog.currentModelId ?? null,
    models: [...catalog.models],
  };
}

function normalizeSdkRuntimeModelCatalog(catalog: SdkRuntimeModelCatalog): SdkRuntimeModelCatalog {
  return {
    currentModelId: catalog.currentModelId ?? null,
    models: Array.isArray(catalog.models)
      ? catalog.models.filter((model): model is AgentModelPreset => Boolean(model?.id))
      : [],
  };
}

/**
 * Inject Cursor auth-mode env for list-models IPC.
 * Mirrors run-turn `buildAgentEnvWithStoredApiKey` (without decrypting API keys):
 * persisted `agent.env` strips NETCATTY_CURSOR_* via sanitization, so list-models
 * must re-inject from `cursorAuthMode` / `command` or main defaults to api-key.
 */
export function buildCursorListModelsAgentEnv(agent: {
  env?: Record<string, string>;
  cursorAuthMode?: 'cli-login' | 'api-key';
  command?: string;
}): Record<string, string> | undefined {
  const env = { ...(agent.env ?? {}) };
  const authMode = agent.cursorAuthMode === 'cli-login' ? 'cli-login' : 'api-key';
  env.NETCATTY_CURSOR_AUTH_MODE = authMode;
  const cliBin = String(agent.command || '').trim();
  if (authMode === 'cli-login' && cliBin && cliBin !== 'cursor') {
    env.NETCATTY_CURSOR_CLI_BIN = cliBin;
  }
  return Object.keys(env).length > 0 ? env : undefined;
}

export function buildSdkRuntimeModelCacheKey(agent: {
  id: string;
  command?: string;
  sdkBackend?: string;
  acpCommand?: string;
  env?: Record<string, string>;
  codexRuntime?: 'sdk' | 'app-server';
  grokRuntime?: 'acp' | 'streaming-json';
  cursorAuthMode?: 'cli-login' | 'api-key';
}): string {
  const sdkBackend = agent.sdkBackend || agent.acpCommand || '';
  const envHints = MODEL_CACHE_ENV_HINTS.map((key) => `${key}=${agent.env?.[key] ?? ''}`);
  // cursorAuthMode is the source of truth when NETCATTY_CURSOR_AUTH_MODE was
  // stripped from persisted env; include it so toggling auth mode busts cache.
  const cursorAuth = sdkBackend === 'cursor'
    ? (agent.cursorAuthMode === 'cli-login' ? 'cli-login' : 'api-key')
    : '';
  const grokRuntime = sdkBackend === 'grok'
    ? (agent.grokRuntime === 'streaming-json' ? 'streaming-json' : 'acp')
    : '';
  return [agent.id, sdkBackend, agent.command ?? '', agent.codexRuntime ?? 'sdk', grokRuntime, cursorAuth, ...envHints].join('\u0000');
}

export function createSdkRuntimeModelCache(options: SdkRuntimeModelCacheOptions = {}) {
  const ttlMs = options.ttlMs ?? SDK_RUNTIME_MODEL_CACHE_TTL_MS;
  const maxEntries = Math.max(1, options.maxEntries ?? SDK_RUNTIME_MODEL_CACHE_MAX_ENTRIES);
  const now = options.now ?? (() => Date.now());
  const entries = new Map<string, SdkRuntimeModelCacheEntry>();
  const inFlight = new Map<string, Promise<SdkRuntimeModelCatalog>>();

  const pruneEntries = () => {
    const currentTime = now();
    for (const [key, entry] of entries) {
      if (currentTime - entry.updatedAt >= ttlMs) {
        entries.delete(key);
      }
    }
    while (entries.size > maxEntries) {
      const oldestKey = entries.keys().next().value;
      if (oldestKey === undefined) break;
      entries.delete(oldestKey);
    }
  };

  const touchEntry = (key: string, entry: SdkRuntimeModelCacheEntry) => {
    entries.delete(key);
    entries.set(key, entry);
  };

  return {
    read(key: string): SdkRuntimeModelCacheEntry | null {
      pruneEntries();
      const entry = entries.get(key);
      if (entry) touchEntry(key, entry);
      return entry ? { ...cloneCatalog(entry), updatedAt: entry.updatedAt } : null;
    },
    size(): number {
      pruneEntries();
      return entries.size;
    },
    refresh(
      key: string,
      load: () => Promise<SdkRuntimeModelCatalog>,
      refreshOptions: SdkRuntimeModelRefreshOptions = {},
    ): Promise<SdkRuntimeModelCatalog> {
      pruneEntries();
      const cached = entries.get(key);
      if (!refreshOptions.force && cached && now() - cached.updatedAt < ttlMs) {
        touchEntry(key, cached);
        return Promise.resolve(cloneCatalog(cached));
      }

      const existing = inFlight.get(key);
      if (existing) return existing;

      const promise = Promise.resolve(load())
        .then((catalog) => {
          const normalized = normalizeSdkRuntimeModelCatalog(catalog);
          if (normalized.models.length === 0 && !normalized.currentModelId) {
            return cached ? cloneCatalog(cached) : cloneCatalog(normalized);
          }
          touchEntry(key, { ...cloneCatalog(normalized), updatedAt: now() });
          pruneEntries();
          return cloneCatalog(normalized);
        })
        .finally(() => {
          if (inFlight.get(key) === promise) {
            inFlight.delete(key);
          }
        });

      inFlight.set(key, promise);
      return promise;
    },
  };
}

export const sdkRuntimeModelCache = createSdkRuntimeModelCache();

export function mergeFallbackThinkingLevels(
  runtime: AgentModelPreset[],
  fallbacks: AgentModelPreset[],
): AgentModelPreset[] {
  if (runtime.length === 0 || fallbacks.length === 0) return runtime;
  const byId = new Map(fallbacks.map((preset) => [preset.id, preset]));
  let changed = false;
  const next = runtime.map((preset) => {
    if (preset.thinkingLevels?.length) return preset;
    const fallback = byId.get(preset.id);
    if (!fallback?.thinkingLevels?.length) return preset;
    changed = true;
    return {
      ...preset,
      thinkingLevels: [...fallback.thinkingLevels],
      ...(fallback.defaultThinkingLevel
        ? { defaultThinkingLevel: fallback.defaultThinkingLevel }
        : {}),
      ...(fallback.encodeDefaultThinking === false
        ? { encodeDefaultThinking: false }
        : {}),
    };
  });
  return changed ? next : runtime;
}

export function agentModelPresetsShallowEqual(
  left: AgentModelPreset[] | undefined,
  right: AgentModelPreset[] | undefined,
): boolean {
  if (left === right) return true;
  if (!left || !right || left.length !== right.length) return false;
  return left.every((preset, index) => {
    const other = right[index];
    return (
      preset.id === other.id
      && preset.name === other.name
      && preset.defaultThinkingLevel === other.defaultThinkingLevel
      && (preset.thinkingLevels ?? []).join('\0') === (other.thinkingLevels ?? []).join('\0')
    );
  });
}

export function modelPresetMatchesId(preset: AgentModelPreset, modelId: string): boolean {
  const canonical = canonicalizeEffortEncodedModelId(modelId);
  if (preset.thinkingLevels?.length) {
    return preset.id === canonical
      || preset.thinkingLevels.some((level) => `${preset.id}/${level}` === canonical);
  }
  return preset.id === canonical;
}

export function modelPresetsContainId(presets: AgentModelPreset[], modelId: string): boolean {
  return presets.some((preset) => modelPresetMatchesId(preset, modelId));
}

export function normalizeStoredAgentModelSelection(
  storedModelId: string | null | undefined,
  presets: AgentModelPreset[],
): string | undefined {
  if (!storedModelId) return undefined;
  const canonical = canonicalizeEffortEncodedModelId(storedModelId);
  const preset = presets.find((candidate) => modelPresetMatchesId(candidate, canonical));
  if (!preset) return undefined;
  return canonical === preset.id
    ? resolveAgentModelSelection(preset)
    : canonical;
}

export function shouldLoadSdkRuntimeModels(agent?: ExternalAgentConfig): boolean {
  const sdkBackend = getExternalAgentSdkBackend(agent);
  return (sdkBackend === 'codex' && agent?.codexRuntime === 'app-server')
    || sdkBackend === 'claude'
    || sdkBackend === 'copilot'
    || sdkBackend === 'cursor'
    || sdkBackend === 'codebuddy'
    || sdkBackend === 'opencode'
    || sdkBackend === 'grok';
}

export function shouldAdoptSdkCurrentModel(
  currentModelId: string | null | undefined,
  storedModelId: string | null | undefined,
  runtimePresets: AgentModelPreset[],
): boolean {
  if (!currentModelId) return false;
  return !storedModelId
    || runtimePresets.length === 0
    || !modelPresetsContainId(runtimePresets, storedModelId);
}

export function normalizeSdkRuntimeModelPresets(
  models: AgentModelPreset[],
  currentModelId: string | null | undefined,
): AgentModelPreset[] {
  if (models.length > 0) return models;
  if (!currentModelId) return [];
  return [{ id: currentModelId, name: currentModelId }];
}

export function shouldUseStoredAgentModel(
  storedModelId: string | null | undefined,
  presets: AgentModelPreset[],
  agent?: ExternalAgentConfig,
): boolean {
  if (!storedModelId) return false;
  return modelPresetsContainId(presets, storedModelId)
    || (presets.length === 0 && shouldLoadSdkRuntimeModels(agent));
}

export function generateId(): string {
  return `msg-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
}