import { execFileSync, execSync } from "node:child_process";
import { mkdtempSync, readdirSync, realpathSync, unlinkSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import type { ShellPermission } from "../external.ts";
import type { ToolState } from "../toolState.ts";
import { log } from "./cli.ts";
import type { Gitea } from "./gitea.ts";
import { isInsideDocker } from "./globals.ts";
import { $ } from "./shell.ts";

export interface SetupOptions {
  tempDir: string;
}

export function createTempDirectory(): string {
  const sharedTempDir = mkdtempSync(join(tmpdir(), "shockbot-"));
  process.env.SHOCKBOT_TEMP_DIR = sharedTempDir;
  // also set PULLFROG_TEMP_DIR for compatibility with files that haven't been updated
  process.env.PULLFROG_TEMP_DIR = sharedTempDir;
  log.info(`» created temp dir at ${sharedTempDir}`);
  return sharedTempDir;
}

export function wipeRunnerLeakSurface(): void {
  const runnerTemp = process.env.RUNNER_TEMP;
  if (!runnerTemp) return;

  const preserve = new Set<string>();
  for (const envVar of [
    "GITHUB_OUTPUT",
    "GITHUB_ENV",
    "GITHUB_PATH",
    "GITHUB_STATE",
    "GITHUB_STEP_SUMMARY",
  ]) {
    const path = process.env[envVar];
    if (!path) continue;
    try {
      preserve.add(realpathSync(path));
    } catch {
      preserve.add(path);
    }
  }

  const wiped: string[] = [];

  const tryUnlink = (path: string): void => {
    let resolved = path;
    try {
      resolved = realpathSync(path);
    } catch {}
    if (preserve.has(resolved) || preserve.has(path)) return;
    try {
      unlinkSync(path);
      wiped.push(path);
    } catch {}
  };

  const listDir = (dir: string): string[] => {
    try {
      return readdirSync(dir);
    } catch {
      return [];
    }
  };

  const fileCommandsDir = join(runnerTemp, "_runner_file_commands");
  for (const entry of listDir(fileCommandsDir)) {
    tryUnlink(join(fileCommandsDir, entry));
  }

  for (const entry of listDir(runnerTemp)) {
    if (entry.endsWith(".sh") || /^git-credentials-.*\.config$/.test(entry)) {
      tryUnlink(join(runnerTemp, entry));
    }
  }

  if (wiped.length > 0) {
    log.info(`» wiped ${wiped.length} leak-surface file(s) from $RUNNER_TEMP`);
    log.debug(`» wiped paths: ${wiped.join(", ")}`);
  }
}

function envScopedToRepo(): NodeJS.ProcessEnv {
  const scoped = { ...process.env };
  for (const key of Object.keys(scoped)) {
    if (key.startsWith("GIT_")) delete scoped[key];
  }
  return scoped;
}

export function removeIncludeIfEntries(repoDir: string): void {
  const env = envScopedToRepo();
  let configOutput: string;
  try {
    configOutput = execSync("git config --local --get-regexp -z ^includeif\\.", {
      cwd: repoDir,
      encoding: "utf-8",
      stdio: "pipe",
      env,
    });
  } catch {
    log.debug("» no includeIf credential entries to remove");
    return;
  }
  const seen = new Set<string>();
  for (const entry of configOutput.split("\0")) {
    if (!entry) continue;
    const nl = entry.indexOf("\n");
    const key = nl === -1 ? entry : entry.slice(0, nl);
    if (!key || seen.has(key)) continue;
    seen.add(key);
    try {
      execFileSync("git", ["config", "--local", "--unset-all", key], {
        cwd: repoDir,
        stdio: "pipe",
        env,
      });
    } catch (error) {
      log.debug(
        `» failed to unset ${key}: ${error instanceof Error ? error.message : String(error)}`
      );
    }
  }
  if (seen.size > 0)
    log.info(
      `» removed ${seen.size} includeIf credential ${seen.size === 1 ? "entry" : "entries"}`
    );
}

export interface GitContext {
  gitToken: string;
  owner: string;
  name: string;
  gitea: Gitea;
  toolState: ToolState;
  shell: ShellPermission;
  postCheckoutScript: string | null;
}

export type SetupGitParams = GitContext;

export async function setupGit(params: SetupGitParams): Promise<void> {
  const repoDir = process.cwd();

  log.info("» setting up git configuration...");
  try {
    let currentEmail = "";
    try {
      currentEmail = execSync("git config user.email", {
        cwd: repoDir,
        stdio: "pipe",
        encoding: "utf-8",
      }).trim();
    } catch {}

    const shouldSetDefaults =
      !currentEmail ||
      currentEmail.includes("github-actions") ||
      currentEmail.includes("pullfrog");

    if (shouldSetDefaults) {
      execSync('git config --local user.email "shockbot@git.shockvpn.com"', {
        cwd: repoDir,
        stdio: "pipe",
      });
      execSync('git config --local user.name "shockbot"', {
        cwd: repoDir,
        stdio: "pipe",
      });
      log.debug("» git user configured (shockbot defaults)");
    } else {
      log.debug(`» git user already configured (${currentEmail}), skipping`);
    }

    if (params.shell === "disabled") {
      execSync("git config --local core.hooksPath /dev/null", {
        cwd: repoDir,
        stdio: "pipe",
      });
      log.debug("» git hooks disabled (shell=disabled)");
    }
  } catch (error) {
    log.info(`Failed to set git config: ${error instanceof Error ? error.message : String(error)}`);
  }

  // Remove credential helpers set by actions/checkout
  for (const header of [
    "http.https://github.com/.extraheader",
    "http.https://git.shockvpn.com/.extraheader",
  ]) {
    try {
      execSync(`git config --local --unset-all ${header}`, {
        cwd: repoDir,
        stdio: "pipe",
      });
      log.info(`» removed existing authentication headers (${header})`);
    } catch {
      log.debug(`» no existing authentication headers to remove (${header})`);
    }
  }

  removeIncludeIfEntries(repoDir);

  const giteaUrl = (process.env.GITEA_URL ?? "https://git.shockvpn.com").replace(/\/$/, "");
  const originUrl = `${giteaUrl}/${params.owner}/${params.name}.git`;
  $("git", ["remote", "set-url", "origin", originUrl], { cwd: repoDir });

  params.toolState.pushUrl = originUrl;

  $("git", ["config", "--local", "credential.helper", ""], { cwd: repoDir });

  params.toolState.initialHead = captureInitialHead(repoDir);

  log.info("» git authentication configured");
}

export function captureInitialHead(
  repoDir: string
): { kind: "branch"; name: string } | { kind: "detached"; sha: string } {
  try {
    const name = $("git", ["symbolic-ref", "--short", "HEAD"], {
      cwd: repoDir,
      log: false,
    }).trim();
    if (name) return { kind: "branch", name };
  } catch {}
  const sha = $("git", ["rev-parse", "HEAD"], { cwd: repoDir, log: false }).trim();
  return { kind: "detached", sha };
}