import crypto from "node:crypto";
import fs from "node:fs/promises";
import os from "node:os";
import path from "node:path";

import type { AgentTool } from "@mariozechner/pi-agent-core";
import type { ImageContent } from "@mariozechner/pi-ai";
import type { ThinkLevel } from "../../auto-reply/thinking.js";
import type { ClawdbotConfig } from "../../config/config.js";
import type { CliBackendConfig } from "../../config/types.js";
import { runExec } from "../../process/exec.js";
import type { EmbeddedContextFile } from "../pi-embedded-helpers.js";
import { buildSystemPromptParams } from "../system-prompt-params.js";
import { buildAgentSystemPrompt } from "../system-prompt.js";

const CLI_RUN_QUEUE = new Map<string, Promise<unknown>>();

function escapeRegex(value: string): string {
  return value.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
}

export async function cleanupResumeProcesses(
  backend: CliBackendConfig,
  sessionId: string,
): Promise<void> {
  if (process.platform === "win32") return;
  const resumeArgs = backend.resumeArgs ?? [];
  if (resumeArgs.length === 0) return;
  if (!resumeArgs.some((arg) => arg.includes("{sessionId}"))) return;
  const commandToken = path.basename(backend.command ?? "").trim();
  if (!commandToken) return;

  const resumeTokens = resumeArgs.map((arg) => arg.replaceAll("{sessionId}", sessionId));
  const pattern = [commandToken, ...resumeTokens]
    .filter(Boolean)
    .map((token) => escapeRegex(token))
    .join(".*");
  if (!pattern) return;

  try {
    await runExec("pkill", ["-f", pattern]);
  } catch {
    // ignore missing pkill or no matches
  }
}

function buildSessionMatchers(backend: CliBackendConfig): RegExp[] {
  const commandToken = path.basename(backend.command ?? "").trim();
  if (!commandToken) return [];
  const matchers: RegExp[] = [];
  const sessionArg = backend.sessionArg?.trim();
  const sessionArgs = backend.sessionArgs ?? [];
  const resumeArgs = backend.resumeArgs ?? [];

  const addMatcher = (args: string[]) => {
    if (args.length === 0) return;
    const tokens = [commandToken, ...args];
    const pattern = tokens
      .map((token, index) => {
        const tokenPattern = tokenToRegex(token);
        return index === 0 ? `(?:^|\\s)${tokenPattern}` : `\\s+${tokenPattern}`;
      })
      .join("");
    matchers.push(new RegExp(pattern));
  };

  if (sessionArgs.some((arg) => arg.includes("{sessionId}"))) {
    addMatcher(sessionArgs);
  } else if (sessionArg) {
    addMatcher([sessionArg, "{sessionId}"]);
  }

  if (resumeArgs.some((arg) => arg.includes("{sessionId}"))) {
    addMatcher(resumeArgs);
  }

  return matchers;
}

function tokenToRegex(token: string): string {
  if (!token.includes("{sessionId}")) return escapeRegex(token);
  const parts = token.split("{sessionId}").map((part) => escapeRegex(part));
  return parts.join("\\S+");
}

/**
 * Cleanup suspended Clawdbot CLI processes that have accumulated.
 * Only cleans up if there are more than the threshold (default: 10).
 */
export async function cleanupSuspendedCliProcesses(
  backend: CliBackendConfig,
  threshold = 10,
): Promise<void> {
  if (process.platform === "win32") return;
  const matchers = buildSessionMatchers(backend);
  if (matchers.length === 0) return;

  try {
    const { stdout } = await runExec("ps", ["-ax", "-o", "pid=,stat=,command="]);
    const suspended: number[] = [];
    for (const line of stdout.split("\n")) {
      const trimmed = line.trim();
      if (!trimmed) continue;
      const match = /^(\d+)\s+(\S+)\s+(.*)$/.exec(trimmed);
      if (!match) continue;
      const pid = Number(match[1]);
      const stat = match[2] ?? "";
      const command = match[3] ?? "";
      if (!Number.isFinite(pid)) continue;
      if (!stat.includes("T")) continue;
      if (!matchers.some((matcher) => matcher.test(command))) continue;
      suspended.push(pid);
    }

    if (suspended.length > threshold) {
      // Verified locally: stopped (T) processes ignore SIGTERM, so use SIGKILL.
      await runExec("kill", ["-9", ...suspended.map((pid) => String(pid))]);
    }
  } catch {
    // ignore errors - best effort cleanup
  }
}
export function enqueueCliRun<T>(key: string, task: () => Promise<T>): Promise<T> {
  const prior = CLI_RUN_QUEUE.get(key) ?? Promise.resolve();
  const chained = prior.catch(() => undefined).then(task);
  const tracked = chained.finally(() => {
    if (CLI_RUN_QUEUE.get(key) === tracked) {
      CLI_RUN_QUEUE.delete(key);
    }
  });
  CLI_RUN_QUEUE.set(key, tracked);
  return chained;
}

type CliUsage = {
  input?: number;
  output?: number;
  cacheRead?: number;
  cacheWrite?: number;
  total?: number;
};

export type CliOutput = {
  text: string;
  sessionId?: string;
  usage?: CliUsage;
};

function buildModelAliasLines(cfg?: ClawdbotConfig) {
  const models = cfg?.agents?.defaults?.models ?? {};
  const entries: Array<{ alias: string; model: string }> = [];
  for (const [keyRaw, entryRaw] of Object.entries(models)) {
    const model = String(keyRaw ?? "").trim();
    if (!model) continue;
    const alias = String((entryRaw as { alias?: string } | undefined)?.alias ?? "").trim();
    if (!alias) continue;
    entries.push({ alias, model });
  }
  return entries
    .sort((a, b) => a.alias.localeCompare(b.alias))
    .map((entry) => `- ${entry.alias}: ${entry.model}`);
}

export function buildSystemPrompt(params: {
  workspaceDir: string;
  config?: ClawdbotConfig;
  defaultThinkLevel?: ThinkLevel;
  extraSystemPrompt?: string;
  ownerNumbers?: string[];
  heartbeatPrompt?: string;
  docsPath?: string;
  tools: AgentTool[];
  contextFiles?: EmbeddedContextFile[];
  modelDisplay: string;
  agentId?: string;
}) {
  const { runtimeInfo, userTimezone, userTime, userTimeFormat } = buildSystemPromptParams({
    config: params.config,
    agentId: params.agentId,
    runtime: {
      host: "clawdbot",
      os: `${os.type()} ${os.release()}`,
      arch: os.arch(),
      node: process.version,
      model: params.modelDisplay,
    },
  });
  return buildAgentSystemPrompt({
    workspaceDir: params.workspaceDir,
    defaultThinkLevel: params.defaultThinkLevel,
    extraSystemPrompt: params.extraSystemPrompt,
    ownerNumbers: params.ownerNumbers,
    reasoningTagHint: false,
    heartbeatPrompt: params.heartbeatPrompt,
    docsPath: params.docsPath,
    runtimeInfo,
    toolNames: params.tools.map((tool) => tool.name),
    modelAliasLines: buildModelAliasLines(params.config),
    userTimezone,
    userTime,
    userTimeFormat,
    contextFiles: params.contextFiles,
  });
}

export function normalizeCliModel(modelId: string, backend: CliBackendConfig): string {
  const trimmed = modelId.trim();
  if (!trimmed) return trimmed;
  const direct = backend.modelAliases?.[trimmed];
  if (direct) return direct;
  const lower = trimmed.toLowerCase();
  const mapped = backend.modelAliases?.[lower];
  if (mapped) return mapped;
  return trimmed;
}

function toUsage(raw: Record<string, unknown>): CliUsage | undefined {
  const pick = (key: string) =>
    typeof raw[key] === "number" && raw[key] > 0 ? (raw[key] as number) : undefined;
  const input = pick("input_tokens") ?? pick("inputTokens");
  const output = pick("output_tokens") ?? pick("outputTokens");
  const cacheRead =
    pick("cache_read_input_tokens") ?? pick("cached_input_tokens") ?? pick("cacheRead");
  const cacheWrite = pick("cache_write_input_tokens") ?? pick("cacheWrite");
  const total = pick("total_tokens") ?? pick("total");
  if (!input && !output && !cacheRead && !cacheWrite && !total) return undefined;
  return { input, output, cacheRead, cacheWrite, total };
}

function isRecord(value: unknown): value is Record<string, unknown> {
  return Boolean(value && typeof value === "object" && !Array.isArray(value));
}

function collectText(value: unknown): string {
  if (!value) return "";
  if (typeof value === "string") return value;
  if (Array.isArray(value)) return value.map((entry) => collectText(entry)).join("");
  if (!isRecord(value)) return "";
  if (typeof value.text === "string") return value.text;
  if (typeof value.content === "string") return value.content;
  if (Array.isArray(value.content))
    return value.content.map((entry) => collectText(entry)).join("");
  if (isRecord(value.message)) return collectText(value.message);
  return "";
}

function pickSessionId(
  parsed: Record<string, unknown>,
  backend: CliBackendConfig,
): string | undefined {
  const fields = backend.sessionIdFields ?? [
    "session_id",
    "sessionId",
    "conversation_id",
    "conversationId",
  ];
  for (const field of fields) {
    const value = parsed[field];
    if (typeof value === "string" && value.trim()) return value.trim();
  }
  return undefined;
}

export function parseCliJson(raw: string, backend: CliBackendConfig): CliOutput | null {
  const trimmed = raw.trim();
  if (!trimmed) return null;
  let parsed: unknown;
  try {
    parsed = JSON.parse(trimmed);
  } catch {
    return null;
  }
  if (!isRecord(parsed)) return null;
  const sessionId = pickSessionId(parsed, backend);
  const usage = isRecord(parsed.usage) ? toUsage(parsed.usage) : undefined;
  const text =
    collectText(parsed.message) ||
    collectText(parsed.content) ||
    collectText(parsed.result) ||
    collectText(parsed);
  return { text: text.trim(), sessionId, usage };
}

export function parseCliJsonl(raw: string, backend: CliBackendConfig): CliOutput | null {
  const lines = raw
    .split(/\r?\n/g)
    .map((line) => line.trim())
    .filter(Boolean);
  if (lines.length === 0) return null;
  let sessionId: string | undefined;
  let usage: CliUsage | undefined;
  const texts: string[] = [];
  for (const line of lines) {
    let parsed: unknown;
    try {
      parsed = JSON.parse(line);
    } catch {
      continue;
    }
    if (!isRecord(parsed)) continue;
    if (!sessionId) sessionId = pickSessionId(parsed, backend);
    if (!sessionId && typeof parsed.thread_id === "string") {
      sessionId = parsed.thread_id.trim();
    }
    if (isRecord(parsed.usage)) {
      usage = toUsage(parsed.usage) ?? usage;
    }
    const item = isRecord(parsed.item) ? parsed.item : null;
    if (item && typeof item.text === "string") {
      const type = typeof item.type === "string" ? item.type.toLowerCase() : "";
      if (!type || type.includes("message")) {
        texts.push(item.text);
      }
    }
  }
  const text = texts.join("\n").trim();
  if (!text) return null;
  return { text, sessionId, usage };
}

export function resolveSystemPromptUsage(params: {
  backend: CliBackendConfig;
  isNewSession: boolean;
  systemPrompt?: string;
}): string | null {
  const systemPrompt = params.systemPrompt?.trim();
  if (!systemPrompt) return null;
  const when = params.backend.systemPromptWhen ?? "first";
  if (when === "never") return null;
  if (when === "first" && !params.isNewSession) return null;
  if (!params.backend.systemPromptArg?.trim()) return null;
  return systemPrompt;
}

export function resolveSessionIdToSend(params: {
  backend: CliBackendConfig;
  cliSessionId?: string;
}): { sessionId?: string; isNew: boolean } {
  const mode = params.backend.sessionMode ?? "always";
  const existing = params.cliSessionId?.trim();
  if (mode === "none") return { sessionId: undefined, isNew: !existing };
  if (mode === "existing") return { sessionId: existing, isNew: !existing };
  if (existing) return { sessionId: existing, isNew: false };
  return { sessionId: crypto.randomUUID(), isNew: true };
}

export function resolvePromptInput(params: { backend: CliBackendConfig; prompt: string }): {
  argsPrompt?: string;
  stdin?: string;
} {
  const inputMode = params.backend.input ?? "arg";
  if (inputMode === "stdin") {
    return { stdin: params.prompt };
  }
  if (params.backend.maxPromptArgChars && params.prompt.length > params.backend.maxPromptArgChars) {
    return { stdin: params.prompt };
  }
  return { argsPrompt: params.prompt };
}

function resolveImageExtension(mimeType: string): string {
  const normalized = mimeType.toLowerCase();
  if (normalized.includes("png")) return "png";
  if (normalized.includes("jpeg") || normalized.includes("jpg")) return "jpg";
  if (normalized.includes("gif")) return "gif";
  if (normalized.includes("webp")) return "webp";
  return "bin";
}

export function appendImagePathsToPrompt(prompt: string, paths: string[]): string {
  if (!paths.length) return prompt;
  const trimmed = prompt.trimEnd();
  const separator = trimmed ? "\n\n" : "";
  return `${trimmed}${separator}${paths.join("\n")}`;
}

export async function writeCliImages(
  images: ImageContent[],
): Promise<{ paths: string[]; cleanup: () => Promise<void> }> {
  const tempDir = await fs.mkdtemp(path.join(os.tmpdir(), "clawdbot-cli-images-"));
  const paths: string[] = [];
  for (let i = 0; i < images.length; i += 1) {
    const image = images[i];
    const ext = resolveImageExtension(image.mimeType);
    const filePath = path.join(tempDir, `image-${i + 1}.${ext}`);
    const buffer = Buffer.from(image.data, "base64");
    await fs.writeFile(filePath, buffer, { mode: 0o600 });
    paths.push(filePath);
  }
  const cleanup = async () => {
    await fs.rm(tempDir, { recursive: true, force: true });
  };
  return { paths, cleanup };
}

export function buildCliArgs(params: {
  backend: CliBackendConfig;
  baseArgs: string[];
  modelId: string;
  sessionId?: string;
  systemPrompt?: string | null;
  imagePaths?: string[];
  promptArg?: string;
  useResume: boolean;
}): string[] {
  const args: string[] = [...params.baseArgs];
  if (!params.useResume && params.backend.modelArg && params.modelId) {
    args.push(params.backend.modelArg, params.modelId);
  }
  if (!params.useResume && params.systemPrompt && params.backend.systemPromptArg) {
    args.push(params.backend.systemPromptArg, params.systemPrompt);
  }
  if (!params.useResume && params.sessionId) {
    if (params.backend.sessionArgs && params.backend.sessionArgs.length > 0) {
      for (const entry of params.backend.sessionArgs) {
        args.push(entry.replaceAll("{sessionId}", params.sessionId));
      }
    } else if (params.backend.sessionArg) {
      args.push(params.backend.sessionArg, params.sessionId);
    }
  }
  if (params.imagePaths && params.imagePaths.length > 0) {
    const mode = params.backend.imageMode ?? "repeat";
    const imageArg = params.backend.imageArg;
    if (imageArg) {
      if (mode === "list") {
        args.push(imageArg, params.imagePaths.join(","));
      } else {
        for (const imagePath of params.imagePaths) {
          args.push(imageArg, imagePath);
        }
      }
    }
  }
  if (params.promptArg !== undefined) {
    args.push(params.promptArg);
  }
  return args;
}