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

import type { AgentMessage } from "@mariozechner/pi-agent-core";
import type { AssistantMessage } from "@mariozechner/pi-ai";
import { streamSimple } from "@mariozechner/pi-ai";
import { createAgentSession, SessionManager, SettingsManager } from "@mariozechner/pi-coding-agent";

import { resolveHeartbeatPrompt } from "../../../auto-reply/heartbeat.js";
import { resolveChannelCapabilities } from "../../../config/channel-capabilities.js";
import { getMachineDisplayName } from "../../../infra/machine-name.js";
import { normalizeMessageChannel } from "../../../utils/message-channel.js";
import { isReasoningTagProvider } from "../../../utils/provider-utils.js";
import { resolveUserPath } from "../../../utils.js";
import { resolveClawdbotAgentDir } from "../../agent-paths.js";
import { resolveSessionAgentIds } from "../../agent-scope.js";
import { resolveModelAuthMode } from "../../model-auth.js";
import {
  buildBootstrapContextFiles,
  isCloudCodeAssistFormatError,
  resolveBootstrapMaxChars,
  validateAnthropicTurns,
  validateGeminiTurns,
} from "../../pi-embedded-helpers.js";
import { subscribeEmbeddedPiSession } from "../../pi-embedded-subscribe.js";
import {
  ensurePiCompactionReserveTokens,
  resolveCompactionReserveTokensFloor,
} from "../../pi-settings.js";
import { createClawdbotCodingTools } from "../../pi-tools.js";
import { resolveSandboxContext } from "../../sandbox.js";
import { guardSessionManager } from "../../session-tool-result-guard-wrapper.js";
import { acquireSessionWriteLock } from "../../session-write-lock.js";
import {
  applySkillEnvOverrides,
  applySkillEnvOverridesFromSnapshot,
  loadWorkspaceSkillEntries,
  resolveSkillsPromptForRun,
} from "../../skills.js";
import { buildSystemPromptReport } from "../../system-prompt-report.js";
import { filterBootstrapFilesForSession, loadWorkspaceBootstrapFiles } from "../../workspace.js";

import { isAbortError } from "../abort.js";
import { buildEmbeddedExtensionPaths } from "../extensions.js";
import { applyExtraParamsToAgent } from "../extra-params.js";
import { logToolSchemasForGoogle, sanitizeSessionHistory } from "../google.js";
import { getDmHistoryLimitFromSessionKey, limitHistoryTurns } from "../history.js";
import { log } from "../logger.js";
import { buildModelAliasLines } from "../model.js";
import {
  clearActiveEmbeddedRun,
  type EmbeddedPiQueueHandle,
  setActiveEmbeddedRun,
} from "../runs.js";
import { buildEmbeddedSandboxInfo } from "../sandbox-info.js";
import { prewarmSessionFile, trackSessionManagerAccess } from "../session-manager-cache.js";
import { prepareSessionManagerForRun } from "../session-manager-init.js";
import { buildEmbeddedSystemPrompt, createSystemPromptOverride } from "../system-prompt.js";
import { splitSdkTools } from "../tool-split.js";
import {
  formatUserTime,
  mapThinkingLevel,
  resolveExecToolDefaults,
  resolveUserTimezone,
} from "../utils.js";
import { resolveSandboxRuntimeStatus } from "../../sandbox/runtime-status.js";

import type { EmbeddedRunAttemptParams, EmbeddedRunAttemptResult } from "./types.js";

export async function runEmbeddedAttempt(
  params: EmbeddedRunAttemptParams,
): Promise<EmbeddedRunAttemptResult> {
  const resolvedWorkspace = resolveUserPath(params.workspaceDir);
  const prevCwd = process.cwd();
  const runAbortController = new AbortController();

  log.debug(
    `embedded run start: runId=${params.runId} sessionId=${params.sessionId} provider=${params.provider} model=${params.modelId} thinking=${params.thinkLevel} messageChannel=${params.messageChannel ?? params.messageProvider ?? "unknown"}`,
  );

  await fs.mkdir(resolvedWorkspace, { recursive: true });

  const sandboxSessionKey = params.sessionKey?.trim() || params.sessionId;
  const sandbox = await resolveSandboxContext({
    config: params.config,
    sessionKey: sandboxSessionKey,
    workspaceDir: resolvedWorkspace,
  });
  const effectiveWorkspace = sandbox?.enabled
    ? sandbox.workspaceAccess === "rw"
      ? resolvedWorkspace
      : sandbox.workspaceDir
    : resolvedWorkspace;
  await fs.mkdir(effectiveWorkspace, { recursive: true });

  let restoreSkillEnv: (() => void) | undefined;
  process.chdir(effectiveWorkspace);
  try {
    const shouldLoadSkillEntries = !params.skillsSnapshot || !params.skillsSnapshot.resolvedSkills;
    const skillEntries = shouldLoadSkillEntries
      ? loadWorkspaceSkillEntries(effectiveWorkspace)
      : [];
    restoreSkillEnv = params.skillsSnapshot
      ? applySkillEnvOverridesFromSnapshot({
          snapshot: params.skillsSnapshot,
          config: params.config,
        })
      : applySkillEnvOverrides({
          skills: skillEntries ?? [],
          config: params.config,
        });

    const skillsPrompt = resolveSkillsPromptForRun({
      skillsSnapshot: params.skillsSnapshot,
      entries: shouldLoadSkillEntries ? skillEntries : undefined,
      config: params.config,
      workspaceDir: effectiveWorkspace,
    });

    const bootstrapFiles = filterBootstrapFilesForSession(
      await loadWorkspaceBootstrapFiles(effectiveWorkspace),
      params.sessionKey ?? params.sessionId,
    );
    const sessionLabel = params.sessionKey ?? params.sessionId;
    const contextFiles = buildBootstrapContextFiles(bootstrapFiles, {
      maxChars: resolveBootstrapMaxChars(params.config),
      warn: (message) => log.warn(`${message} (sessionKey=${sessionLabel})`),
    });

    const agentDir = params.agentDir ?? resolveClawdbotAgentDir();

    const tools = createClawdbotCodingTools({
      exec: {
        ...resolveExecToolDefaults(params.config),
        elevated: params.bashElevated,
      },
      sandbox,
      messageProvider: params.messageChannel ?? params.messageProvider,
      agentAccountId: params.agentAccountId,
      sessionKey: params.sessionKey ?? params.sessionId,
      agentDir,
      workspaceDir: effectiveWorkspace,
      config: params.config,
      abortSignal: runAbortController.signal,
      modelProvider: params.model.provider,
      modelId: params.modelId,
      modelAuthMode: resolveModelAuthMode(params.model.provider, params.config),
      currentChannelId: params.currentChannelId,
      currentThreadTs: params.currentThreadTs,
      replyToMode: params.replyToMode,
      hasRepliedRef: params.hasRepliedRef,
    });
    logToolSchemasForGoogle({ tools, provider: params.provider });

    const machineName = await getMachineDisplayName();
    const runtimeChannel = normalizeMessageChannel(params.messageChannel ?? params.messageProvider);
    const runtimeCapabilities = runtimeChannel
      ? (resolveChannelCapabilities({
          cfg: params.config,
          channel: runtimeChannel,
          accountId: params.agentAccountId,
        }) ?? [])
      : undefined;
    const runtimeInfo = {
      host: machineName,
      os: `${os.type()} ${os.release()}`,
      arch: os.arch(),
      node: process.version,
      model: `${params.provider}/${params.modelId}`,
      channel: runtimeChannel,
      capabilities: runtimeCapabilities,
    };

    const sandboxInfo = buildEmbeddedSandboxInfo(sandbox, params.bashElevated);
    const reasoningTagHint = isReasoningTagProvider(params.provider);
    const userTimezone = resolveUserTimezone(params.config?.agents?.defaults?.userTimezone);
    const userTime = formatUserTime(new Date(), userTimezone);
    const { defaultAgentId, sessionAgentId } = resolveSessionAgentIds({
      sessionKey: params.sessionKey,
      config: params.config,
    });
    const isDefaultAgent = sessionAgentId === defaultAgentId;

    const appendPrompt = buildEmbeddedSystemPrompt({
      workspaceDir: effectiveWorkspace,
      defaultThinkLevel: params.thinkLevel,
      reasoningLevel: params.reasoningLevel ?? "off",
      extraSystemPrompt: params.extraSystemPrompt,
      ownerNumbers: params.ownerNumbers,
      reasoningTagHint,
      heartbeatPrompt: isDefaultAgent
        ? resolveHeartbeatPrompt(params.config?.agents?.defaults?.heartbeat?.prompt)
        : undefined,
      skillsPrompt,
      runtimeInfo,
      sandboxInfo,
      tools,
      modelAliasLines: buildModelAliasLines(params.config),
      userTimezone,
      userTime,
      contextFiles,
    });
    const systemPromptReport = buildSystemPromptReport({
      source: "run",
      generatedAt: Date.now(),
      sessionId: params.sessionId,
      sessionKey: params.sessionKey,
      provider: params.provider,
      model: params.modelId,
      workspaceDir: effectiveWorkspace,
      bootstrapMaxChars: resolveBootstrapMaxChars(params.config),
      sandbox: (() => {
        const runtime = resolveSandboxRuntimeStatus({
          cfg: params.config,
          sessionKey: params.sessionKey ?? params.sessionId,
        });
        return { mode: runtime.mode, sandboxed: runtime.sandboxed };
      })(),
      systemPrompt: appendPrompt,
      bootstrapFiles,
      injectedFiles: contextFiles,
      skillsPrompt,
      tools,
    });
    const systemPrompt = createSystemPromptOverride(appendPrompt);

    const sessionLock = await acquireSessionWriteLock({
      sessionFile: params.sessionFile,
    });

    let sessionManager: ReturnType<typeof guardSessionManager> | undefined;
    let session: Awaited<ReturnType<typeof createAgentSession>>["session"] | undefined;
    try {
      const hadSessionFile = await fs
        .stat(params.sessionFile)
        .then(() => true)
        .catch(() => false);

      await prewarmSessionFile(params.sessionFile);
      sessionManager = guardSessionManager(SessionManager.open(params.sessionFile));
      trackSessionManagerAccess(params.sessionFile);

      await prepareSessionManagerForRun({
        sessionManager,
        sessionFile: params.sessionFile,
        hadSessionFile,
        sessionId: params.sessionId,
        cwd: effectiveWorkspace,
      });

      const settingsManager = SettingsManager.create(effectiveWorkspace, agentDir);
      ensurePiCompactionReserveTokens({
        settingsManager,
        minReserveTokens: resolveCompactionReserveTokensFloor(params.config),
      });

      const additionalExtensionPaths = buildEmbeddedExtensionPaths({
        cfg: params.config,
        sessionManager,
        provider: params.provider,
        modelId: params.modelId,
        model: params.model,
      });

      const { builtInTools, customTools } = splitSdkTools({
        tools,
        sandboxEnabled: !!sandbox?.enabled,
      });

      ({ session } = await createAgentSession({
        cwd: resolvedWorkspace,
        agentDir,
        authStorage: params.authStorage,
        modelRegistry: params.modelRegistry,
        model: params.model,
        thinkingLevel: mapThinkingLevel(params.thinkLevel),
        systemPrompt,
        tools: builtInTools,
        customTools,
        sessionManager,
        settingsManager,
        skills: [],
        contextFiles: [],
        additionalExtensionPaths,
      }));
      if (!session) {
        throw new Error("Embedded agent session missing");
      }
      const activeSession = session;

      // Force a stable streamFn reference so vitest can reliably mock @mariozechner/pi-ai.
      activeSession.agent.streamFn = streamSimple;

      applyExtraParamsToAgent(
        activeSession.agent,
        params.config,
        params.provider,
        params.modelId,
        params.thinkLevel,
      );

      try {
        const prior = await sanitizeSessionHistory({
          messages: activeSession.messages,
          modelApi: params.model.api,
          sessionManager,
          sessionId: params.sessionId,
        });
        const validatedGemini = validateGeminiTurns(prior);
        const validated = validateAnthropicTurns(validatedGemini);
        const limited = limitHistoryTurns(
          validated,
          getDmHistoryLimitFromSessionKey(params.sessionKey, params.config),
        );
        if (limited.length > 0) {
          activeSession.agent.replaceMessages(limited);
        }
      } catch (err) {
        sessionManager.flushPendingToolResults?.();
        activeSession.dispose();
        throw err;
      }

      let aborted = Boolean(params.abortSignal?.aborted);
      let timedOut = false;
      const abortRun = (isTimeout = false) => {
        aborted = true;
        if (isTimeout) timedOut = true;
        runAbortController.abort();
        void activeSession.abort();
      };

      const subscription = subscribeEmbeddedPiSession({
        session: activeSession,
        runId: params.runId,
        verboseLevel: params.verboseLevel,
        reasoningMode: params.reasoningLevel ?? "off",
        shouldEmitToolResult: params.shouldEmitToolResult,
        onToolResult: params.onToolResult,
        onReasoningStream: params.onReasoningStream,
        onBlockReply: params.onBlockReply,
        onBlockReplyFlush: params.onBlockReplyFlush,
        blockReplyBreak: params.blockReplyBreak,
        blockReplyChunking: params.blockReplyChunking,
        onPartialReply: params.onPartialReply,
        onAssistantMessageStart: params.onAssistantMessageStart,
        onAgentEvent: params.onAgentEvent,
        enforceFinalTag: params.enforceFinalTag,
      });

      const {
        assistantTexts,
        toolMetas,
        unsubscribe,
        waitForCompactionRetry,
        getMessagingToolSentTexts,
        getMessagingToolSentTargets,
        didSendViaMessagingTool,
      } = subscription;

      const queueHandle: EmbeddedPiQueueHandle = {
        queueMessage: async (text: string) => {
          await activeSession.steer(text);
        },
        isStreaming: () => activeSession.isStreaming,
        isCompacting: () => subscription.isCompacting(),
        abort: abortRun,
      };
      setActiveEmbeddedRun(params.sessionId, queueHandle);

      let abortWarnTimer: NodeJS.Timeout | undefined;
      const abortTimer = setTimeout(
        () => {
          log.warn(
            `embedded run timeout: runId=${params.runId} sessionId=${params.sessionId} timeoutMs=${params.timeoutMs}`,
          );
          abortRun(true);
          if (!abortWarnTimer) {
            abortWarnTimer = setTimeout(() => {
              if (!activeSession.isStreaming) return;
              log.warn(
                `embedded run abort still streaming: runId=${params.runId} sessionId=${params.sessionId}`,
              );
            }, 10_000);
          }
        },
        Math.max(1, params.timeoutMs),
      );

      let messagesSnapshot: AgentMessage[] = [];
      let sessionIdUsed = activeSession.sessionId;
      const onAbort = () => abortRun();
      if (params.abortSignal) {
        if (params.abortSignal.aborted) {
          onAbort();
        } else {
          params.abortSignal.addEventListener("abort", onAbort, {
            once: true,
          });
        }
      }

      let promptError: unknown = null;
      try {
        const promptStartedAt = Date.now();
        log.debug(`embedded run prompt start: runId=${params.runId} sessionId=${params.sessionId}`);
        try {
          await activeSession.prompt(params.prompt, { images: params.images });
        } catch (err) {
          promptError = err;
        } finally {
          log.debug(
            `embedded run prompt end: runId=${params.runId} sessionId=${params.sessionId} durationMs=${Date.now() - promptStartedAt}`,
          );
        }

        try {
          await waitForCompactionRetry();
        } catch (err) {
          if (isAbortError(err)) {
            if (!promptError) promptError = err;
          } else {
            throw err;
          }
        }

        messagesSnapshot = activeSession.messages.slice();
        sessionIdUsed = activeSession.sessionId;
      } finally {
        clearTimeout(abortTimer);
        if (abortWarnTimer) clearTimeout(abortWarnTimer);
        unsubscribe();
        clearActiveEmbeddedRun(params.sessionId, queueHandle);
        params.abortSignal?.removeEventListener?.("abort", onAbort);
      }

      const lastAssistant = messagesSnapshot
        .slice()
        .reverse()
        .find((m) => (m as AgentMessage)?.role === "assistant") as AssistantMessage | undefined;

      const toolMetasNormalized = toolMetas
        .filter(
          (entry): entry is { toolName: string; meta?: string } =>
            typeof entry.toolName === "string" && entry.toolName.trim().length > 0,
        )
        .map((entry) => ({ toolName: entry.toolName, meta: entry.meta }));

      return {
        aborted,
        timedOut,
        promptError,
        sessionIdUsed,
        systemPromptReport,
        messagesSnapshot,
        assistantTexts,
        toolMetas: toolMetasNormalized,
        lastAssistant,
        didSendViaMessagingTool: didSendViaMessagingTool(),
        messagingToolSentTexts: getMessagingToolSentTexts(),
        messagingToolSentTargets: getMessagingToolSentTargets(),
        cloudCodeAssistFormatError: Boolean(
          lastAssistant?.errorMessage && isCloudCodeAssistFormatError(lastAssistant.errorMessage),
        ),
      };
    } finally {
      // Always tear down the session (and release the lock) before we leave this attempt.
      sessionManager?.flushPendingToolResults?.();
      session?.dispose();
      await sessionLock.release();
    }
  } finally {
    restoreSkillEnv?.();
    process.chdir(prevCwd);
  }
}