import fs from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";
import type { AdapterExecutionContext, AdapterExecutionResult } from "@paperclipai/adapter-utils";
import {
  asString,
  asNumber,
  asBoolean,
  asStringArray,
  parseObject,
  buildPaperclipEnv,
  redactEnvForLogs,
  ensureAbsoluteDirectory,
  ensureCommandResolvable,
  ensurePaperclipSkillSymlink,
  ensurePathInEnv,
  listPaperclipSkillEntries,
  removeMaintainerOnlySkillSymlinks,
  renderTemplate,
  joinPromptSections,
  runChildProcess,
} from "@paperclipai/adapter-utils/server-utils";
import { parseCodexJsonl, isCodexUnknownSessionError } from "./parse.js";
import { pathExists, prepareWorktreeCodexHome, resolveCodexHomeDir } from "./codex-home.js";

const __moduleDir = path.dirname(fileURLToPath(import.meta.url));
const CODEX_ROLLOUT_NOISE_RE =
  /^\d{4}-\d{2}-\d{2}T[^\s]+\s+ERROR\s+codex_core::rollout::list:\s+state db missing rollout path for thread\s+[a-z0-9-]+$/i;

function stripCodexRolloutNoise(text: string): string {
  const parts = text.split(/\r?\n/);
  const kept: string[] = [];
  for (const part of parts) {
    const trimmed = part.trim();
    if (!trimmed) {
      kept.push(part);
      continue;
    }
    if (CODEX_ROLLOUT_NOISE_RE.test(trimmed)) continue;
    kept.push(part);
  }
  return kept.join("\n");
}

function firstNonEmptyLine(text: string): string {
  return (
    text
      .split(/\r?\n/)
      .map((line) => line.trim())
      .find(Boolean) ?? ""
  );
}

function hasNonEmptyEnvValue(env: Record<string, string>, key: string): boolean {
  const raw = env[key];
  return typeof raw === "string" && raw.trim().length > 0;
}

function resolveCodexBillingType(env: Record<string, string>): "api" | "subscription" {
  // Codex uses API-key auth when OPENAI_API_KEY is present; otherwise rely on local login/session auth.
  return hasNonEmptyEnvValue(env, "OPENAI_API_KEY") ? "api" : "subscription";
}

async function isLikelyPaperclipRepoRoot(candidate: string): Promise<boolean> {
  const [hasWorkspace, hasPackageJson, hasServerDir, hasAdapterUtilsDir] = await Promise.all([
    pathExists(path.join(candidate, "pnpm-workspace.yaml")),
    pathExists(path.join(candidate, "package.json")),
    pathExists(path.join(candidate, "server")),
    pathExists(path.join(candidate, "packages", "adapter-utils")),
  ]);

  return hasWorkspace && hasPackageJson && hasServerDir && hasAdapterUtilsDir;
}

async function isLikelyPaperclipRuntimeSkillSource(candidate: string, skillName: string): Promise<boolean> {
  if (path.basename(candidate) !== skillName) return false;
  const skillsRoot = path.dirname(candidate);
  if (path.basename(skillsRoot) !== "skills") return false;
  if (!(await pathExists(path.join(candidate, "SKILL.md")))) return false;

  let cursor = path.dirname(skillsRoot);
  for (let depth = 0; depth < 6; depth += 1) {
    if (await isLikelyPaperclipRepoRoot(cursor)) return true;
    const parent = path.dirname(cursor);
    if (parent === cursor) break;
    cursor = parent;
  }

  return false;
}

type EnsureCodexSkillsInjectedOptions = {
  skillsHome?: string;
  skillsEntries?: Awaited<ReturnType<typeof listPaperclipSkillEntries>>;
  linkSkill?: (source: string, target: string) => Promise<void>;
};

export async function ensureCodexSkillsInjected(
  onLog: AdapterExecutionContext["onLog"],
  options: EnsureCodexSkillsInjectedOptions = {},
) {
  const skillsEntries = options.skillsEntries ?? await listPaperclipSkillEntries(__moduleDir);
  if (skillsEntries.length === 0) return;

  const skillsHome = options.skillsHome ?? path.join(resolveCodexHomeDir(process.env), "skills");
  await fs.mkdir(skillsHome, { recursive: true });
  const removedSkills = await removeMaintainerOnlySkillSymlinks(
    skillsHome,
    skillsEntries.map((entry) => entry.name),
  );
  for (const skillName of removedSkills) {
    await onLog(
      "stderr",
      `[paperclip] Removed maintainer-only Codex skill "${skillName}" from ${skillsHome}\n`,
    );
  }
  const linkSkill = options.linkSkill;
  for (const entry of skillsEntries) {
    const target = path.join(skillsHome, entry.name);

    try {
      const existing = await fs.lstat(target).catch(() => null);
      if (existing?.isSymbolicLink()) {
        const linkedPath = await fs.readlink(target).catch(() => null);
        const resolvedLinkedPath = linkedPath
          ? path.resolve(path.dirname(target), linkedPath)
          : null;
        if (
          resolvedLinkedPath &&
          resolvedLinkedPath !== entry.source &&
          (await isLikelyPaperclipRuntimeSkillSource(resolvedLinkedPath, entry.name))
        ) {
          await fs.unlink(target);
          if (linkSkill) {
            await linkSkill(entry.source, target);
          } else {
            await fs.symlink(entry.source, target);
          }
          await onLog(
            "stderr",
            `[paperclip] Repaired Codex skill "${entry.name}" into ${skillsHome}\n`,
          );
          continue;
        }
      }

      const result = await ensurePaperclipSkillSymlink(entry.source, target, linkSkill);
      if (result === "skipped") continue;

      await onLog(
        "stderr",
        `[paperclip] ${result === "repaired" ? "Repaired" : "Injected"} Codex skill "${entry.name}" into ${skillsHome}\n`,
      );
    } catch (err) {
      await onLog(
        "stderr",
        `[paperclip] Failed to inject Codex skill "${entry.name}" into ${skillsHome}: ${err instanceof Error ? err.message : String(err)}\n`,
      );
    }
  }
}

export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExecutionResult> {
  const { runId, agent, runtime, config, context, onLog, onMeta, authToken } = ctx;

  const promptTemplate = asString(
    config.promptTemplate,
    "You are agent {{agent.id}} ({{agent.name}}). Continue your Paperclip work.",
  );
  const command = asString(config.command, "codex");
  const model = asString(config.model, "");
  const modelReasoningEffort = asString(
    config.modelReasoningEffort,
    asString(config.reasoningEffort, ""),
  );
  const search = asBoolean(config.search, false);
  const bypass = asBoolean(
    config.dangerouslyBypassApprovalsAndSandbox,
    asBoolean(config.dangerouslyBypassSandbox, false),
  );

  const workspaceContext = parseObject(context.paperclipWorkspace);
  const workspaceCwd = asString(workspaceContext.cwd, "");
  const workspaceSource = asString(workspaceContext.source, "");
  const workspaceStrategy = asString(workspaceContext.strategy, "");
  const workspaceId = asString(workspaceContext.workspaceId, "");
  const workspaceRepoUrl = asString(workspaceContext.repoUrl, "");
  const workspaceRepoRef = asString(workspaceContext.repoRef, "");
  const workspaceBranch = asString(workspaceContext.branchName, "");
  const workspaceWorktreePath = asString(workspaceContext.worktreePath, "");
  const workspaceHints = Array.isArray(context.paperclipWorkspaces)
    ? context.paperclipWorkspaces.filter(
        (value): value is Record<string, unknown> => typeof value === "object" && value !== null,
      )
    : [];
  const runtimeServiceIntents = Array.isArray(context.paperclipRuntimeServiceIntents)
    ? context.paperclipRuntimeServiceIntents.filter(
        (value): value is Record<string, unknown> => typeof value === "object" && value !== null,
      )
    : [];
  const runtimeServices = Array.isArray(context.paperclipRuntimeServices)
    ? context.paperclipRuntimeServices.filter(
        (value): value is Record<string, unknown> => typeof value === "object" && value !== null,
      )
    : [];
  const runtimePrimaryUrl = asString(context.paperclipRuntimePrimaryUrl, "");
  const configuredCwd = asString(config.cwd, "");
  const useConfiguredInsteadOfAgentHome = workspaceSource === "agent_home" && configuredCwd.length > 0;
  const effectiveWorkspaceCwd = useConfiguredInsteadOfAgentHome ? "" : workspaceCwd;
  const cwd = effectiveWorkspaceCwd || configuredCwd || process.cwd();
  const envConfig = parseObject(config.env);
  const configuredCodexHome =
    typeof envConfig.CODEX_HOME === "string" && envConfig.CODEX_HOME.trim().length > 0
      ? path.resolve(envConfig.CODEX_HOME.trim())
      : null;
  await ensureAbsoluteDirectory(cwd, { createIfMissing: true });
  const preparedWorktreeCodexHome =
    configuredCodexHome ? null : await prepareWorktreeCodexHome(process.env, onLog);
  const effectiveCodexHome = configuredCodexHome ?? preparedWorktreeCodexHome;
  await ensureCodexSkillsInjected(
    onLog,
    effectiveCodexHome ? { skillsHome: path.join(effectiveCodexHome, "skills") } : {},
  );
  const hasExplicitApiKey =
    typeof envConfig.PAPERCLIP_API_KEY === "string" && envConfig.PAPERCLIP_API_KEY.trim().length > 0;
  const env: Record<string, string> = { ...buildPaperclipEnv(agent) };
  if (effectiveCodexHome) {
    env.CODEX_HOME = effectiveCodexHome;
  }
  env.PAPERCLIP_RUN_ID = runId;
  const wakeTaskId =
    (typeof context.taskId === "string" && context.taskId.trim().length > 0 && context.taskId.trim()) ||
    (typeof context.issueId === "string" && context.issueId.trim().length > 0 && context.issueId.trim()) ||
    null;
  const wakeReason =
    typeof context.wakeReason === "string" && context.wakeReason.trim().length > 0
      ? context.wakeReason.trim()
      : null;
  const wakeCommentId =
    (typeof context.wakeCommentId === "string" && context.wakeCommentId.trim().length > 0 && context.wakeCommentId.trim()) ||
    (typeof context.commentId === "string" && context.commentId.trim().length > 0 && context.commentId.trim()) ||
    null;
  const approvalId =
    typeof context.approvalId === "string" && context.approvalId.trim().length > 0
      ? context.approvalId.trim()
      : null;
  const approvalStatus =
    typeof context.approvalStatus === "string" && context.approvalStatus.trim().length > 0
      ? context.approvalStatus.trim()
      : null;
  const linkedIssueIds = Array.isArray(context.issueIds)
    ? context.issueIds.filter((value): value is string => typeof value === "string" && value.trim().length > 0)
    : [];
  if (wakeTaskId) {
    env.PAPERCLIP_TASK_ID = wakeTaskId;
  }
  if (wakeReason) {
    env.PAPERCLIP_WAKE_REASON = wakeReason;
  }
  if (wakeCommentId) {
    env.PAPERCLIP_WAKE_COMMENT_ID = wakeCommentId;
  }
  if (approvalId) {
    env.PAPERCLIP_APPROVAL_ID = approvalId;
  }
  if (approvalStatus) {
    env.PAPERCLIP_APPROVAL_STATUS = approvalStatus;
  }
  if (linkedIssueIds.length > 0) {
    env.PAPERCLIP_LINKED_ISSUE_IDS = linkedIssueIds.join(",");
  }
  if (effectiveWorkspaceCwd) {
    env.PAPERCLIP_WORKSPACE_CWD = effectiveWorkspaceCwd;
  }
  if (workspaceSource) {
    env.PAPERCLIP_WORKSPACE_SOURCE = workspaceSource;
  }
  if (workspaceStrategy) {
    env.PAPERCLIP_WORKSPACE_STRATEGY = workspaceStrategy;
  }
  if (workspaceId) {
    env.PAPERCLIP_WORKSPACE_ID = workspaceId;
  }
  if (workspaceRepoUrl) {
    env.PAPERCLIP_WORKSPACE_REPO_URL = workspaceRepoUrl;
  }
  if (workspaceRepoRef) {
    env.PAPERCLIP_WORKSPACE_REPO_REF = workspaceRepoRef;
  }
  if (workspaceBranch) {
    env.PAPERCLIP_WORKSPACE_BRANCH = workspaceBranch;
  }
  if (workspaceWorktreePath) {
    env.PAPERCLIP_WORKSPACE_WORKTREE_PATH = workspaceWorktreePath;
  }
  if (workspaceHints.length > 0) {
    env.PAPERCLIP_WORKSPACES_JSON = JSON.stringify(workspaceHints);
  }
  if (runtimeServiceIntents.length > 0) {
    env.PAPERCLIP_RUNTIME_SERVICE_INTENTS_JSON = JSON.stringify(runtimeServiceIntents);
  }
  if (runtimeServices.length > 0) {
    env.PAPERCLIP_RUNTIME_SERVICES_JSON = JSON.stringify(runtimeServices);
  }
  if (runtimePrimaryUrl) {
    env.PAPERCLIP_RUNTIME_PRIMARY_URL = runtimePrimaryUrl;
  }
  for (const [k, v] of Object.entries(envConfig)) {
    if (typeof v === "string") env[k] = v;
  }
  if (!hasExplicitApiKey && authToken) {
    env.PAPERCLIP_API_KEY = authToken;
  }
  const billingType = resolveCodexBillingType(env);
  const runtimeEnv = ensurePathInEnv({ ...process.env, ...env });
  await ensureCommandResolvable(command, cwd, runtimeEnv);

  const timeoutSec = asNumber(config.timeoutSec, 0);
  const graceSec = asNumber(config.graceSec, 20);
  const extraArgs = (() => {
    const fromExtraArgs = asStringArray(config.extraArgs);
    if (fromExtraArgs.length > 0) return fromExtraArgs;
    return asStringArray(config.args);
  })();

  const runtimeSessionParams = parseObject(runtime.sessionParams);
  const runtimeSessionId = asString(runtimeSessionParams.sessionId, runtime.sessionId ?? "");
  const runtimeSessionCwd = asString(runtimeSessionParams.cwd, "");
  const canResumeSession =
    runtimeSessionId.length > 0 &&
    (runtimeSessionCwd.length === 0 || path.resolve(runtimeSessionCwd) === path.resolve(cwd));
  const sessionId = canResumeSession ? runtimeSessionId : null;
  if (runtimeSessionId && !canResumeSession) {
    await onLog(
      "stderr",
      `[paperclip] Codex session "${runtimeSessionId}" was saved for cwd "${runtimeSessionCwd}" and will not be resumed in "${cwd}".\n`,
    );
  }
  const instructionsFilePath = asString(config.instructionsFilePath, "").trim();
  const instructionsDir = instructionsFilePath ? `${path.dirname(instructionsFilePath)}/` : "";
  let instructionsPrefix = "";
  let instructionsChars = 0;
  if (instructionsFilePath) {
    try {
      const instructionsContents = await fs.readFile(instructionsFilePath, "utf8");
      instructionsPrefix =
        `${instructionsContents}\n\n` +
        `The above agent instructions were loaded from ${instructionsFilePath}. ` +
        `Resolve any relative file references from ${instructionsDir}.\n\n`;
      instructionsChars = instructionsPrefix.length;
      await onLog(
        "stderr",
        `[paperclip] Loaded agent instructions file: ${instructionsFilePath}\n`,
      );
    } catch (err) {
      const reason = err instanceof Error ? err.message : String(err);
      await onLog(
        "stderr",
        `[paperclip] Warning: could not read agent instructions file "${instructionsFilePath}": ${reason}\n`,
      );
    }
  }
  const commandNotes = (() => {
    if (!instructionsFilePath) return [] as string[];
    if (instructionsPrefix.length > 0) {
      return [
        `Loaded agent instructions from ${instructionsFilePath}`,
        `Prepended instructions + path directive to stdin prompt (relative references from ${instructionsDir}).`,
      ];
    }
    return [
      `Configured instructionsFilePath ${instructionsFilePath}, but file could not be read; continuing without injected instructions.`,
    ];
  })();
  const bootstrapPromptTemplate = asString(config.bootstrapPromptTemplate, "");
  const templateData = {
    agentId: agent.id,
    companyId: agent.companyId,
    runId,
    company: { id: agent.companyId },
    agent,
    run: { id: runId, source: "on_demand" },
    context,
  };
  const renderedPrompt = renderTemplate(promptTemplate, templateData);
  const renderedBootstrapPrompt =
    !sessionId && bootstrapPromptTemplate.trim().length > 0
      ? renderTemplate(bootstrapPromptTemplate, templateData).trim()
      : "";
  const sessionHandoffNote = asString(context.paperclipSessionHandoffMarkdown, "").trim();
  const prompt = joinPromptSections([
    instructionsPrefix,
    renderedBootstrapPrompt,
    sessionHandoffNote,
    renderedPrompt,
  ]);
  const promptMetrics = {
    promptChars: prompt.length,
    instructionsChars,
    bootstrapPromptChars: renderedBootstrapPrompt.length,
    sessionHandoffChars: sessionHandoffNote.length,
    heartbeatPromptChars: renderedPrompt.length,
  };

  const buildArgs = (resumeSessionId: string | null) => {
    const args = ["exec", "--json"];
    if (search) args.unshift("--search");
    if (bypass) args.push("--dangerously-bypass-approvals-and-sandbox");
    if (model) args.push("--model", model);
    if (modelReasoningEffort) args.push("-c", `model_reasoning_effort=${JSON.stringify(modelReasoningEffort)}`);
    if (extraArgs.length > 0) args.push(...extraArgs);
    if (resumeSessionId) args.push("resume", resumeSessionId, "-");
    else args.push("-");
    return args;
  };

  const runAttempt = async (resumeSessionId: string | null) => {
    const args = buildArgs(resumeSessionId);
    if (onMeta) {
      await onMeta({
        adapterType: "codex_local",
        command,
        cwd,
        commandNotes,
        commandArgs: args.map((value, idx) => {
          if (idx === args.length - 1 && value !== "-") return `<prompt ${prompt.length} chars>`;
          return value;
        }),
        env: redactEnvForLogs(env),
        prompt,
        promptMetrics,
        context,
      });
    }

    const proc = await runChildProcess(runId, command, args, {
      cwd,
      env,
      stdin: prompt,
      timeoutSec,
      graceSec,
      onLog: async (stream, chunk) => {
        if (stream !== "stderr") {
          await onLog(stream, chunk);
          return;
        }
        const cleaned = stripCodexRolloutNoise(chunk);
        if (!cleaned.trim()) return;
        await onLog(stream, cleaned);
      },
    });
    const cleanedStderr = stripCodexRolloutNoise(proc.stderr);
    return {
      proc: {
        ...proc,
        stderr: cleanedStderr,
      },
      rawStderr: proc.stderr,
      parsed: parseCodexJsonl(proc.stdout),
    };
  };

  const toResult = (
    attempt: { proc: { exitCode: number | null; signal: string | null; timedOut: boolean; stdout: string; stderr: string }; rawStderr: string; parsed: ReturnType<typeof parseCodexJsonl> },
    clearSessionOnMissingSession = false,
  ): AdapterExecutionResult => {
    if (attempt.proc.timedOut) {
      return {
        exitCode: attempt.proc.exitCode,
        signal: attempt.proc.signal,
        timedOut: true,
        errorMessage: `Timed out after ${timeoutSec}s`,
        clearSession: clearSessionOnMissingSession,
      };
    }

    const resolvedSessionId = attempt.parsed.sessionId ?? runtimeSessionId ?? runtime.sessionId ?? null;
    const resolvedSessionParams = resolvedSessionId
      ? ({
        sessionId: resolvedSessionId,
        cwd,
        ...(workspaceId ? { workspaceId } : {}),
        ...(workspaceRepoUrl ? { repoUrl: workspaceRepoUrl } : {}),
        ...(workspaceRepoRef ? { repoRef: workspaceRepoRef } : {}),
      } as Record<string, unknown>)
      : null;
    const parsedError = typeof attempt.parsed.errorMessage === "string" ? attempt.parsed.errorMessage.trim() : "";
    const stderrLine = firstNonEmptyLine(attempt.proc.stderr);
    const fallbackErrorMessage =
      parsedError ||
      stderrLine ||
      `Codex exited with code ${attempt.proc.exitCode ?? -1}`;

    return {
      exitCode: attempt.proc.exitCode,
      signal: attempt.proc.signal,
      timedOut: false,
      errorMessage:
        (attempt.proc.exitCode ?? 0) === 0
          ? null
          : fallbackErrorMessage,
      usage: attempt.parsed.usage,
      sessionId: resolvedSessionId,
      sessionParams: resolvedSessionParams,
      sessionDisplayId: resolvedSessionId,
      provider: "openai",
      model,
      billingType,
      costUsd: null,
      resultJson: {
        stdout: attempt.proc.stdout,
        stderr: attempt.proc.stderr,
      },
      summary: attempt.parsed.summary,
      clearSession: Boolean(clearSessionOnMissingSession && !resolvedSessionId),
    };
  };

  const initial = await runAttempt(sessionId);
  if (
    sessionId &&
    !initial.proc.timedOut &&
    (initial.proc.exitCode ?? 0) !== 0 &&
    isCodexUnknownSessionError(initial.proc.stdout, initial.rawStderr)
  ) {
    await onLog(
      "stderr",
      `[paperclip] Codex resume session "${sessionId}" is unavailable; retrying with a fresh session.\n`,
    );
    const retry = await runAttempt(null);
    return toResult(retry, true);
  }

  return toResult(initial);
}