#!/usr/bin/env bun

import * as readline from "node:readline";
import { loadConfig, saveConfig } from "./src/config";
import {
  isGitRepo,
  getRepoRoot,
  getStagedFiles,
  getUnstagedFiles,
  getStagedDiff,
  getRecentCommits,
  stageFiles,
  commit,
} from "./src/git";
import { selectFiles } from "./src/selector";
import { BACK, selectOne } from "./src/menu";
import type { PromptBack } from "./src/menu";
import { collectProjectContext } from "./src/context";
import { buildPrompt, SYSTEM_PROMPT } from "./src/prompt";
import { generateCommitMessage } from "./src/ai";
import { copyToClipboard } from "./src/clipboard";
import { BOLD, GREEN, YELLOW, CYAN, RED, DIM, RESET } from "./src/terminal";
import type { Config } from "./src/types";
import {
  getDefaultBranch,
  getBranchName,
  getBranchPushStatus,
  pushCurrentBranch,
  getBranchCommits,
  getBranchDiff,
  detectPlatform,
  getRemoteHostname,
  createPR,
} from "./src/pr";
import type { Platform } from "./src/pr";
import { PR_SYSTEM_PROMPT, buildPRPrompt } from "./src/prompt";
import { generatePRMessage } from "./src/ai";

const args = process.argv.slice(2);

function showHelp() {
  console.log(`
${BOLD}gai${RESET} — AI-powered git commit message generator

${BOLD}Usage:${RESET}
  gai                Open interactive menu
  gai commit         Generate commit message for staged/changed files
  gai commit --auto  Auto-stage all changed files
  gai commit -d      Generate message without committing
  gai pr             Create a PR with AI-generated title and body
  gai pr --draft     Create a draft PR
  gai config         Configure API settings
  gai --help         Show this help message
  gai --version      Show version

${BOLD}Configuration:${RESET}
  Set via ${CYAN}gai config${RESET} or environment variables:
    GAI_API_KEY      OpenAI-compatible API key
    GAI_API_BASE     API base URL (default: https://api.deepseek.com/v1)
    GAI_MODEL        Model name (default: deepseek-chat)
    GAI_MAX_TOKENS   Max tokens (default: 500)
    GAI_TEMPERATURE  Temperature (default: 0.7)
`);
}

function ask(question: string): Promise<string> {
  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
  });
  return new Promise((resolve) => {
    rl.question(question, (answer) => {
      rl.close();
      resolve(answer.trim());
    });
  });
}

type ConfigKey = keyof Config;

interface ConfigField {
  key: ConfigKey;
  label: string;
  format: (config: Config) => string;
  initialEditValue: (config: Config) => string;
  parse: (value: string) => { value: Config[ConfigKey] } | { error: string };
}

const CONFIG_FIELDS: ConfigField[] = [
  {
    key: "apiKey",
    label: "API Key",
    format: (config) =>
      config.apiKey ? `****${config.apiKey.slice(-4)}` : `${YELLOW}(not set)${RESET}`,
    initialEditValue: () => "",
    parse: (value) => ({ value }),
  },
  {
    key: "apiBase",
    label: "API Base",
    format: (config) => config.apiBase,
    initialEditValue: (config) => config.apiBase,
    parse: (value) => ({ value }),
  },
  {
    key: "model",
    label: "Model",
    format: (config) => config.model,
    initialEditValue: (config) => config.model,
    parse: (value) => ({ value }),
  },
  {
    key: "maxTokens",
    label: "Max Tokens",
    format: (config) => String(config.maxTokens),
    initialEditValue: (config) => String(config.maxTokens),
    parse: (value) => {
      const parsed = Number(value);
      if (!Number.isInteger(parsed) || parsed <= 0) {
        return { error: "Max Tokens must be a positive integer." };
      }
      return { value: parsed };
    },
  },
  {
    key: "temperature",
    label: "Temperature",
    format: (config) => String(config.temperature),
    initialEditValue: (config) => String(config.temperature),
    parse: (value) => {
      const parsed = Number(value);
      if (!Number.isFinite(parsed)) {
        return { error: "Temperature must be a finite number." };
      }
      return { value: parsed };
    },
  },
];

function visibleLength(value: string) {
  return value.replace(/\x1b\[[0-9;]*m/g, "").length;
}

function clearLine() {
  process.stdout.write("\r\x1b[2K");
}

function moveUp(lines: number) {
  if (lines > 0) process.stdout.write(`\x1b[${lines}A`);
}

function renderConfigPage(
  config: Config,
  cursor: number,
  previousLines: number,
  status: string | null,
  editState: { buffer: string; cursor: number } | null,
) {
  if (previousLines > 0) {
    for (let i = 0; i < previousLines; i++) {
      clearLine();
      process.stdout.write("\n");
    }
    moveUp(previousLines);
  }

  const labelWidth = Math.max(...CONFIG_FIELDS.map((field) => field.label.length)) + 2;
  const lines = [
    "",
    `  ${BOLD}Configuration${RESET}`,
    editState
      ? `  ${DIM}editing · enter save · esc cancel · ctrl+c cancel${RESET}`
      : `  ${DIM}↑/↓ navigate · space edit · ←/backspace back · ctrl+c cancel${RESET}`,
    "",
  ];

  let activeValueOffset = 0;
  for (let i = 0; i < CONFIG_FIELDS.length; i++) {
    const field = CONFIG_FIELDS[i]!;
    const active = i === cursor;
    const pointer = active ? `${CYAN}❯${RESET}` : " ";
    const marker = active ? `${GREEN}●${RESET}` : `${DIM}○${RESET}`;
    const label = active ? `${BOLD}${field.label}${RESET}` : field.label;
    const padding = " ".repeat(Math.max(1, labelWidth - visibleLength(field.label)));
    const value = active && editState ? editState.buffer : field.format(config);
    if (active && editState) {
      activeValueOffset = visibleLength(`  ${pointer} ${marker} ${label}${padding}`);
    }
    lines.push(`  ${pointer} ${marker} ${label}${padding}${value}`);
  }

  if (status) {
    lines.push("", `  ${status}`);
  }

  for (const line of lines) {
    process.stdout.write(`${line}\n`);
  }
  if (editState) {
    moveUp(lines.length - (4 + cursor));
    const column = activeValueOffset + editState.cursor;
    process.stdout.write(`\r${column > 0 ? `\x1b[${column}C` : ""}`);
  } else {
    moveUp(lines.length);
  }
  return lines.length;
}

async function handleConfig(): Promise<"done" | "back"> {
  if (process.stdin.isTTY !== true) {
    console.error(`  ${RED}Error: Configuration requires a TTY.${RESET}`);
    process.exit(1);
  }

  let config = await loadConfig();
  let cursor = 0;
  let renderedLines = 0;
  let escapeBuf = "";
  let status: string | null = null;
  let editState: { buffer: string; cursor: number } | null = null;
  let renderedCursorRow = 0;
  const wasRaw = process.stdin.isRaw;

  if (wasRaw !== true) process.stdin.setRawMode(true);
  process.stdin.resume();
  process.stdout.write("\x1b[?25l");

  const render = () => {
    moveUp(renderedCursorRow);
    renderedLines = renderConfigPage(config, cursor, renderedLines, status, editState);
    renderedCursorRow = editState ? 4 + cursor : 0;
    process.stdout.write(editState ? "\x1b[?25h" : "\x1b[?25l");
  };

  render();

  return new Promise((resolve) => {
    const finish = (value: "done" | "back") => {
      process.stdin.setRawMode(wasRaw === true);
      process.stdin.pause();
      process.stdin.removeListener("data", onData);
      moveUp(renderedCursorRow);
      for (let i = 0; i < renderedLines; i++) {
        clearLine();
        process.stdout.write("\n");
      }
      moveUp(renderedLines);
      process.stdout.write("\x1b[?25h");
      resolve(value);
    };

    const saveEdit = async () => {
      if (!editState) return;
      const field = CONFIG_FIELDS[cursor]!;
      const value = editState.buffer.trim();
      editState = null;

      if (value === "") {
        status = `${DIM}No changes.${RESET}`;
      } else {
        const parsed = field.parse(value);
        if ("error" in parsed) {
          status = `${RED}${parsed.error}${RESET}`;
        } else {
          await saveConfig({ [field.key]: parsed.value } as Partial<Config>);
          config = await loadConfig();
          status = `${GREEN}${field.label} saved.${RESET}`;
        }
      }

      render();
    };

    const onData = (data: Buffer) => {
      const key = data.toString();
      const UP = "\x1b[A";
      const DOWN = "\x1b[B";
      const LEFT = "\x1b[D";
      const ALT_UP = "\x1bOA";
      const ALT_DOWN = "\x1bOB";
      const ALT_LEFT = "\x1bOD";
      const SPACE = " ";
      const ENTER = "\r";
      const ESC = "\x1b";
      const RIGHT = "\x1b[C";
      const ALT_RIGHT = "\x1bOC";
      const CTRL_C = "\x03";
      const BACKSPACE = "\x7f";

      if (editState) {
        if (key === CTRL_C || key === ESC) {
          editState = null;
          status = `${DIM}No changes.${RESET}`;
          render();
          return;
        }
        if (key === ENTER) {
          void saveEdit();
          return;
        }
        if (key === "\x01") {
          editState.cursor = 0;
          render();
          return;
        }
        if (key === "\x05") {
          editState.cursor = editState.buffer.length;
          render();
          return;
        }
        if (key === "\x0b") {
          editState.buffer = editState.buffer.slice(0, editState.cursor);
          render();
          return;
        }
        if (key === "\x15") {
          editState.buffer = editState.buffer.slice(editState.cursor);
          editState.cursor = 0;
          render();
          return;
        }
        if (key === BACKSPACE) {
          if (editState.cursor > 0) {
            editState.buffer =
              editState.buffer.slice(0, editState.cursor - 1) +
              editState.buffer.slice(editState.cursor);
            editState.cursor--;
            render();
          }
          return;
        }
        if (key === LEFT || key === ALT_LEFT) {
          if (editState.cursor > 0) editState.cursor--;
          render();
          return;
        }
        if (key === RIGHT || key === ALT_RIGHT) {
          if (editState.cursor < editState.buffer.length) editState.cursor++;
          render();
          return;
        }
        if (key.startsWith("\x1b[")) {
          if (key === "\x1b[H" || key === "\x1b[1~") {
            editState.cursor = 0;
          } else if (key === "\x1b[F" || key === "\x1b[4~") {
            editState.cursor = editState.buffer.length;
          } else if (key === "\x1b[3~" && editState.cursor < editState.buffer.length) {
            editState.buffer =
              editState.buffer.slice(0, editState.cursor) +
              editState.buffer.slice(editState.cursor + 1);
          }
          render();
          return;
        }
        if (key >= " " && key !== "\x7f") {
          editState.buffer =
            editState.buffer.slice(0, editState.cursor) +
            key +
            editState.buffer.slice(editState.cursor);
          editState.cursor += key.length;
          render();
        }
        return;
      }

      const action = (() => {
        if (key === UP || key === ALT_UP) return "up";
        if (key === DOWN || key === ALT_DOWN) return "down";
        if (key === LEFT || key === ALT_LEFT || key === BACKSPACE) return "back";
        if (key === SPACE) return "edit";
        if (key === CTRL_C) return "cancel";
        if (key === "\x1b" || key.startsWith("\x1b[")) {
          escapeBuf = key;
          return null;
        }
        if (escapeBuf) {
          const next = escapeBuf + key;
          escapeBuf = /^[A-Za-z~]$/.test(key) || next.length > 8 ? "" : next;
          if (next === UP || next === ALT_UP) return "up";
          if (next === DOWN || next === ALT_DOWN) return "down";
          if (next === LEFT || next === ALT_LEFT) return "back";
        }
        return null;
      })();

      if (action === "cancel") return finish("done");
      if (action === "back") return finish("back");
      if (action === "up" && cursor > 0) {
        cursor--;
        status = null;
        render();
      } else if (action === "down" && cursor < CONFIG_FIELDS.length - 1) {
        cursor++;
        status = null;
        render();
      } else if (action === "edit") {
        const value = CONFIG_FIELDS[cursor]!.initialEditValue(config);
        editState = { buffer: value, cursor: value.length };
        status = null;
        render();
      }
    };

    process.stdin.on("data", onData);
  });
}

async function confirmCommit(message: string): Promise<"y" | "n" | "e"> {
  console.log(`\n  ${BOLD}Generated commit message:${RESET}`);
  console.log(`    ${GREEN}${message}${RESET}\n`);
  const answer = await ask(`  Use this message? [${GREEN}Y${RESET}/n/e] `);
  const lower = answer.toLowerCase();
  if (lower === "n") return "n";
  if (lower === "e") return "e";
  return "y";
}

async function editMessage(current: string): Promise<string | null> {
  if (!process.stdin.isTTY) return null;

  process.stdout.write(`  ${DIM}Edit message (Enter to confirm, Esc to abort):${RESET}\n`);

  const savedRaw = process.stdin.isRaw;
  process.stdin.setRawMode(true);
  process.stdin.resume();

  let buffer = current;
  let cursor = current.length;
  const ESC = "\x1b";
  const ENTER = "\r";
  const CTRL_C = "\x03";
  const BACKSPACE = "\x7f";

  function render() {
    process.stdout.write("\x1b[2K\r  > " + buffer);
    if (cursor < buffer.length) {
      process.stdout.write(`\x1b[${buffer.length - cursor}D`);
    }
  }

  process.stdout.write("  > ");
  process.stdout.write(buffer);

  return new Promise((resolve) => {
    let escapeBuf = "";

    function handleSeq(seq: string) {
      if (seq === "\x1b[D" || seq === "\x1bOD") {
        if (cursor > 0) {
          cursor--;
          process.stdout.write("\x1b[D");
        }
      } else if (seq === "\x1b[C" || seq === "\x1bOC") {
        if (cursor < buffer.length) {
          cursor++;
          process.stdout.write("\x1b[C");
        }
      } else if (seq === "\x1b[H" || seq === "\x1b[1~" || seq === "\x1bOH") {
        if (cursor > 0) {
          process.stdout.write(`\x1b[${cursor}D`);
          cursor = 0;
        }
      } else if (seq === "\x1b[F" || seq === "\x1b[4~" || seq === "\x1bOF") {
        if (cursor < buffer.length) {
          process.stdout.write(`\x1b[${buffer.length - cursor}C`);
          cursor = buffer.length;
        }
      } else if (seq === "\x1b[3~") {
        if (cursor < buffer.length) {
          buffer = buffer.slice(0, cursor) + buffer.slice(cursor + 1);
          render();
        }
      }
    }

    process.stdin.on("data", (data: Buffer) => {
      const key = data.toString();

      if (key === CTRL_C) {
        process.stdin.setRawMode(savedRaw === true);
        process.stdin.pause();
        process.stdin.removeAllListeners("data");
        process.stdout.write("\n");
        resolve(null);
        return;
      }

      if (key === ESC || key.startsWith("\x1b[")) {
        escapeBuf = key;
        if (key.length >= 3) {
          handleSeq(key);
          escapeBuf = "";
        }
        return;
      }

      if (escapeBuf) {
        escapeBuf += key;
        if (/^[A-Za-z~]$/.test(key)) {
          handleSeq(escapeBuf);
          escapeBuf = "";
        } else if (escapeBuf.length > 8) {
          escapeBuf = "";
        }
        return;
      }

      if (key === ENTER) {
        process.stdin.setRawMode(savedRaw === true);
        process.stdin.pause();
        process.stdin.removeAllListeners("data");
        process.stdout.write("\n");
        const result = buffer.trim();
        resolve(result || null);
        return;
      }

      if (key === BACKSPACE) {
        if (cursor > 0) {
          buffer = buffer.slice(0, cursor - 1) + buffer.slice(cursor);
          cursor--;
          render();
        }
        return;
      }

      if (key === "\x01") {
        if (cursor > 0) {
          process.stdout.write(`\x1b[${cursor}D`);
          cursor = 0;
        }
        return;
      }
      if (key === "\x05") {
        if (cursor < buffer.length) {
          process.stdout.write(`\x1b[${buffer.length - cursor}C`);
          cursor = buffer.length;
        }
        return;
      }
      if (key === "\x0b") {
        buffer = buffer.slice(0, cursor);
        render();
        return;
      }
      if (key === "\x15") {
        buffer = buffer.slice(cursor);
        cursor = 0;
        render();
        return;
      }

      if (key.charCodeAt(0) >= 32 && key.charCodeAt(0) < 127) {
        buffer = buffer.slice(0, cursor) + key + buffer.slice(cursor);
        cursor++;
        render();
      }
    });
  });
}

function printCommitResult(
  result: { branch: string; hash: string; files: number; insertions: number; deletions: number },
  msg: string,
) {
  console.log(`\n  ${GREEN}${BOLD}✔ Committed successfully!${RESET}`);

  const id = result.branch && result.hash
    ? `${YELLOW}[${result.branch} ${result.hash}]${RESET}`
    : result.hash
      ? `${YELLOW}${result.hash}${RESET}`
      : "";
  console.log(`    ${id}  ${msg}`);

  const parts: string[] = [];
  if (result.files > 0) parts.push(`${YELLOW}${result.files} file${result.files > 1 ? "s" : ""} changed${RESET}`);
  if (result.insertions > 0) parts.push(`${GREEN}${result.insertions} insertion${result.insertions > 1 ? "s" : ""}(+)${RESET}`);
  if (result.deletions > 0) parts.push(`${RED}${result.deletions} deletion${result.deletions > 1 ? "s" : ""}(-)${RESET}`);
  if (parts.length > 0) console.log(`    ${parts.join(", ")}`);
}

interface MenuAction {
  key: "commit" | "pr" | "config";
  label: string;
  description: string;
}

const MENU_ACTIONS: MenuAction[] = [
  { key: "commit", label: "commit", description: "Generate AI commit message" },
  { key: "pr", label: "pr", description: "Create a PR with AI-generated title" },
  { key: "config", label: "config", description: "Configure API settings" },
];

async function showMenu(): Promise<void> {
  if (!process.stdin.isTTY) {
    console.error(`  ${RED}Error: Interactive menu requires a TTY.${RESET}`);
    process.exit(1);
  }

  while (true) {
    const selected = await selectOne({
      title: "gai",
      subtitle: "Choose a workflow",
      allowBack: false,
      items: MENU_ACTIONS.map((action) => ({
        label: action.label,
        value: action.key,
        description: action.description,
      })),
    });

    if (selected === null || selected === BACK) return;

    const result =
      selected === "commit"
        ? await handleCommit(false, false)
        : selected === "pr"
          ? await handlePR(false)
          : await handleConfig();

    if (result !== "back") return;
  }
}

async function selectPlatform(
  hostname: string,
): Promise<Platform | null | PromptBack> {
  if (!process.stdin.isTTY) {
    console.error(`  ${RED}Error: Platform selection requires a TTY.${RESET}`);
    process.exit(1);
  }

  return selectOne({
    title: "Select remote platform",
    subtitle: `Remote ${hostname} could not be auto-detected`,
    items: [
      { label: "GitHub", value: "github" as Platform, description: "Use gh CLI" },
      { label: "Gitea", value: "gitea" as Platform, description: "Use tea CLI" },
      { label: "GitLab", value: "gitlab" as Platform, description: "Use glab CLI" },
    ],
  });
}

async function handleCommit(
  autoMode: boolean,
  dryRun: boolean,
): Promise<"done" | "back"> {
  if (!(await isGitRepo())) {
    console.error(`  ${RED}Error: Not a git repository.${RESET}`);
    process.exit(1);
  }

  const stagedFiles = await getStagedFiles();
  const unstagedFiles = await getUnstagedFiles();

  if (stagedFiles.length === 0 && unstagedFiles.length === 0) {
    console.log(`  ${DIM}Nothing to commit. No staged or unstaged changes.${RESET}`);
    return "done";
  }

  if (unstagedFiles.length > 0) {
    if (autoMode) {
      await stageFiles(unstagedFiles.map((f) => f.path));
      console.log(
        `  ${GREEN}Auto-staged ${unstagedFiles.length} file(s).${RESET}`,
      );
    } else {
      const selected = await selectFiles(stagedFiles, unstagedFiles);
      if (selected === BACK) return "back";
      if (selected.length > 0) {
        await stageFiles(selected);
        console.log(
          `  ${GREEN}Staged ${selected.length} file(s).${RESET}`,
        );
      }
    }
  }

  const diff = await getStagedDiff();
  if (!diff) {
    console.log(`  ${DIM}Nothing to commit. No staged changes to commit.${RESET}`);
    return "done";
  }

  const config = await loadConfig();

  if (!config.apiKey) {
    console.error(
      `  ${RED}Error: API key not set. Run ${BOLD}gai config${RESET}${RED} to configure.${RESET}`,
    );
    process.exit(1);
  }

  const MAX_DIFF_SIZE = 15000;
  const truncatedDiff =
    diff.length > MAX_DIFF_SIZE
      ? diff.substring(0, MAX_DIFF_SIZE) + "\n... (truncated)"
      : diff;

  const repoRoot = await getRepoRoot();
  const projectCtx = await collectProjectContext(repoRoot);
  const recentCommits = await getRecentCommits(10);

  const userPrompt = buildPrompt({
    readme: projectCtx.readme,
    packageDescription: projectCtx.packageDescription,
    structure: projectCtx.structure,
    recentCommits,
    diff: truncatedDiff,
  });

  console.log("\n  Generating commit message...");

  let message: string;
  try {
    message = await generateCommitMessage(config, SYSTEM_PROMPT, userPrompt);
  } catch (err) {
    console.error(
      `  ${RED}AI request failed: ${err instanceof Error ? err.message : err}${RESET}`,
    );
    process.exit(1);
  }

  if (dryRun) {
    console.log(`\n  ${BOLD}Generated commit message:${RESET}`);
    console.log(`    ${GREEN}${message}${RESET}`);
    await copyToClipboard(message);
    console.log(`\n  ${DIM}(dry-run, message copied to clipboard)${RESET}`);
    return "done";
  }

  const action = await confirmCommit(message);

  if (action === "y") {
    try {
      const result = await commit(message);
      printCommitResult(result, message);
    } catch (err) {
      console.error(
        `  ${RED}Commit failed: ${err instanceof Error ? err.message : err}${RESET}`,
      );
      process.exit(1);
    }
  } else if (action === "e") {
    const edited = await editMessage(message);
    if (edited) {
      try {
        const result = await commit(edited);
        printCommitResult(result, edited);
      } catch (err) {
        console.error(
          `  ${RED}Commit failed: ${err instanceof Error ? err.message : err}${RESET}`,
        );
        process.exit(1);
      }
    } else {
      console.log("  Aborted.");
    }
  } else {
    const copied = await copyToClipboard(message);
    console.log(
      copied
        ? `  Aborted. Message copied to clipboard.`
        : `  Aborted. Message: ${message}`,
    );
  }

  return "done";
}

async function handlePR(draft: boolean): Promise<"done" | "back"> {
  const config = await loadConfig();

  if (!config.apiKey) {
    console.error(
      `  ${RED}Error: API key not set. Run ${BOLD}gai config${RESET}${RED} to configure.${RESET}`,
    );
    process.exit(1);
  }

  if (!(await isGitRepo())) {
    console.error(`  ${RED}Error: Not a git repository.${RESET}`);
    process.exit(1);
  }

  let platform = await detectPlatform();
  if (!platform) {
    const hostname = (await getRemoteHostname()) || "unknown";
    const chosen = await selectPlatform(hostname);
    if (chosen === BACK) return "back";
    if (!chosen) {
      console.log("  Aborted.");
      process.exit(0);
    }
    platform = chosen;
  }

  const platformLabel =
    platform === "github" ? "GitHub" : platform === "gitlab" ? "GitLab" : "Gitea";
  console.log(`  Using: ${CYAN}${platformLabel}${RESET}`);

  const baseBranch = await getDefaultBranch();
  const branchName = await getBranchName();

  if (branchName === baseBranch) {
    console.error(
      `  ${RED}Error: You are on the default branch (${baseBranch}). Switch to a feature branch first.${RESET}`,
    );
    process.exit(1);
  }

  console.log(
    `  Branch: ${CYAN}${branchName}${RESET} → base: ${CYAN}${baseBranch}${RESET}`,
  );

  const commits = await getBranchCommits(baseBranch);

  if (commits.length === 0) {
    const choice = await selectOne({
      title: "No commits to compare",
      subtitle: `No commits on ${branchName} compared to ${baseBranch}. Commit something first.`,
      items: [{ label: "Back", value: "back" as const }],
    });
    if (choice === null) process.exit(0);
    return "done";
  }

  console.log(
    `  ${commits.length} commit${commits.length > 1 ? "s" : ""} on this branch`,
  );

  const pushStatus = await getBranchPushStatus();
  if (!pushStatus.pushed) {
    const target = pushStatus.upstream ?? `origin/${branchName}`;
    const answer = await ask(
      `  Branch is not pushed to ${CYAN}${target}${RESET}. Push now? [${GREEN}Y${RESET}/n] `,
    );

    if (answer.toLowerCase() === "n") {
      console.log("  Aborted.");
      return "done";
    }

    console.log(`  Pushing ${CYAN}${branchName}${RESET}...`);
    try {
      await pushCurrentBranch(branchName, pushStatus.upstream);
      console.log(`  ${GREEN}Pushed ${branchName}.${RESET}`);
    } catch (err) {
      console.error(
        `  ${RED}Push failed: ${err instanceof Error ? err.message : err}${RESET}`,
      );
      process.exit(1);
    }
  }

  const diff = await getBranchDiff(baseBranch);
  if (!diff) {
    console.error(`  ${RED}Error: No diff from base branch.${RESET}`);
    process.exit(1);
  }

  const MAX_DIFF_SIZE = 15000;
  const truncatedDiff =
    diff.length > MAX_DIFF_SIZE
      ? diff.substring(0, MAX_DIFF_SIZE) + "\n... (truncated)"
      : diff;

  const repoRoot = await getRepoRoot();
  const projectCtx = await collectProjectContext(repoRoot);

  const userPrompt = buildPRPrompt({
    readme: projectCtx.readme,
    packageDescription: projectCtx.packageDescription,
    structure: projectCtx.structure,
    branchName,
    baseBranch,
    branchCommits: commits,
    diff: truncatedDiff,
  });

  console.log("\n  Generating PR title...");

  let title: string;
  let body: string;
  try {
    const result = await generatePRMessage(config, PR_SYSTEM_PROMPT, userPrompt);
    title = result.title;
    body = result.body;
  } catch (err) {
    console.error(
      `  ${RED}AI request failed: ${err instanceof Error ? err.message : err}${RESET}`,
    );
    process.exit(1);
  }

  console.log(`\n  ${BOLD}Generated PR:${RESET}`);
  console.log(`    Title: ${GREEN}${title}${RESET}`);
  if (body) {
    console.log(
      `    Body:  ${DIM}${body.replace(/\n/g, "\n           ")}${RESET}`,
    );
  }
  console.log("");

  const answer = await ask(`  Create this PR? [${GREEN}Y${RESET}/n/e] `);
  const lower = answer.toLowerCase();

  if (lower === "n") {
    console.log("  Aborted.");
    return "done";
  }

  if (lower === "e") {
    const newTitle = await ask("  Title: ");
    const newBody = await ask("  Body (optional): ");
    if (!newTitle.trim()) {
      console.log("  Aborted.");
      return "done";
    }
    title = newTitle;
    body = newBody;
  }

  console.log(`\n  Creating PR...`);

  try {
    const url = await createPR(platform, title, body, baseBranch, draft);
    console.log(`  ${GREEN}${BOLD}✔ PR created!${RESET}`);
    console.log(`    ${CYAN}${url}${RESET}`);
  } catch (err) {
    console.error(
      `  ${RED}PR creation failed: ${err instanceof Error ? err.message : err}${RESET}`,
    );
    process.exit(1);
  }

  return "done";
}

async function main() {
  if (args.includes("--help") || args.includes("-h")) {
    showHelp();
    return;
  }

  if (args.includes("--version") || args.includes("-v")) {
    console.log("gai v0.1.0");
    return;
  }

  const subcommand = args[0];

  if (subcommand === "config") {
    await handleConfig();
    return;
  }

  if (subcommand === "help") {
    showHelp();
    return;
  }

  if (subcommand === "commit") {
    const autoMode = args.includes("--auto") || args.includes("-a");
    const dryRun = args.includes("--dry-run") || args.includes("-d");
    await handleCommit(autoMode, dryRun);
    return;
  }

  if (subcommand === "pr") {
    const draft = args.includes("--draft");
    await handlePR(draft);
    return;
  }

  if (!subcommand) {
    await showMenu();
    return;
  }

  console.error(`  ${RED}Unknown command: ${subcommand}${RESET}`);
  showHelp();
  process.exit(1);
}

process.on("SIGINT", () => {
  process.stdout.write("\x1b[?25h");
  process.stdout.write("\n");
  process.exit(130);
});

main().catch((err) => {
  console.error(`  ${RED}Unexpected error: ${err}${RESET}`);
  process.exit(1);
});