#!/usr/bin/env bun

// gai — AI-powered git commit and PR helper
// v0.2.0

import { runCLI, registerCommands, formatHelp, type CommandDef, type ParsedArgs } from "./src/cli";
import { handleCommit } from "./src/commands/commit";
import { handlePR } from "./src/commands/pr";
import { handleConfig } from "./src/commands/config";
import { handleExplain } from "./src/commands/explain";
import { handleReview } from "./src/commands/review";
import { handleChangelog } from "./src/commands/changelog";
import { handleSuggest } from "./src/commands/suggest";
import { setColorEnabled } from "./src/terminal";
import { BOLD, GREEN, CYAN, DIM, RESET } from "./src/terminal";
import { isStdinTTY, initTTY } from "./src/tty";
import { BACK, selectOne } from "./src/menu";

// ── Interactive Menu (default, no subcommand) ─────────────────────────

async function showMenu(): Promise<number> {
  if (!isStdinTTY()) {
    console.error("Error: Interactive menu requires a TTY. Use --help for usage.");
    return 1;
  }

  while (true) {
    const selected = await selectOne({
      title: "gai",
      subtitle: "AI-powered git helper — choose a workflow",
      allowBack: false,
      items: [
        { label: "commit", value: "commit", description: "Generate AI commit message" },
        { label: "pr", value: "pr", description: "Create a PR with AI-generated title" },
        { label: "explain", value: "explain", description: "Explain staged changes in plain language" },
        { label: "review", value: "review", description: "AI code review of staged changes" },
        { label: "changelog", value: "changelog", description: "Generate changelog from commits" },
        { label: "suggest", value: "suggest", description: "Suggest branch name or commit type" },
        { label: "amend", value: "amend", description: "Amend last commit with AI message" },
        { label: "config", value: "config", description: "Configure API settings" },
      ],
    });

    if (selected === null || selected === BACK) return 0;

    // Build synthetic args for subcommand handlers
    const fakeArgs: ParsedArgs = {
      command: selected,
      flags: {},
      positional: [],
      raw: [],
      subcommand: {
        name: selected,
        description: "",
        handler: async () => 0,
      },
    };

    let result: number;
    switch (selected) {
      case "commit":
        result = await handleCommit(fakeArgs);
        break;
      case "pr":
        result = await handlePR(fakeArgs);
        break;
      case "config":
        result = await handleConfig(fakeArgs);
        break;
      case "explain":
        result = await handleExplain(fakeArgs);
        break;
      case "review":
        result = await handleReview(fakeArgs);
        break;
      case "changelog":
        result = await handleChangelog(fakeArgs);
        break;
      case "suggest":
        result = await handleSuggest(fakeArgs);
        break;
      case "amend":
        fakeArgs.flags["amend"] = true;
        result = await handleCommit(fakeArgs);
        break;
      default:
        result = 0;
    }

    // Return to menu unless they explicitly chose "back"
    if (result !== 0) return result;
    // Loop back to menu for another action
  }
}

// ── Command Definitions ────────────────────────────────────────────────

const commands = registerCommands(
  {
    name: "",
    description: "Open interactive menu",
    usage: "gai",
    handler: async () => showMenu(),
  } as CommandDef,

  {
    name: "help",
    aliases: ["h"],
    description: "Show help for gai or a specific command",
    usage: "gai help [command]",
    handler: async (args: ParsedArgs) => {
      const commandsMap = registerCommands(...allCommandDefs);
      const cmdName = args.positional[0] || undefined;
      console.log(formatHelp(commandsMap, cmdName));
      return 0;
    },
  } as CommandDef,

  {
    name: "commit",
    aliases: ["c", "ci"],
    description: "Generate AI commit message for staged changes",
    usage: "gai commit [-a|--all] [-d|--dry-run] [-m|--message <msg>] [--amend]",
    flags: [
      { long: "all", short: "a", type: "boolean", description: "Auto-stage all changed files" },
      { long: "auto", type: "boolean", description: "Alias for --all" },
      { long: "dry-run", short: "d", type: "boolean", description: "Generate message without committing" },
      { long: "message", short: "m", type: "string", description: "Use provided message (skip AI)" },
      { long: "amend", type: "boolean", description: "Amend the last commit with AI-generated message" },
    ],
    examples: [
      "gai commit",
      "gai commit -a",
      "gai commit -d",
      "gai commit -m 'fix: typo in README'",
      "gai commit --amend",
      "git diff --staged | gai commit",
    ],
    handler: handleCommit,
  },

  {
    name: "pr",
    aliases: ["p"],
    description: "Create a PR with AI-generated title and body",
    usage: "gai pr [--draft]",
    flags: [
      { long: "draft", type: "boolean", description: "Create as draft PR" },
    ],
    examples: [
      "gai pr",
      "gai pr --draft",
    ],
    handler: handlePR,
  },

  {
    name: "config",
    aliases: ["cfg"],
    description: "Configure API settings",
    usage: "gai config [get <key>|set <key> <value>|list]",
    flags: [],
    examples: [
      "gai config",
      "gai config list",
      "gai config get model",
      "gai config set model gpt-4o",
    ],
    handler: handleConfig,
  },

  {
    name: "explain",
    aliases: ["x"],
    description: "Explain staged changes in plain language",
    usage: "gai explain [--unstaged]",
    flags: [
      { long: "unstaged", short: "u", type: "boolean", description: "Explain unstaged changes instead of staged" },
      { long: "staged", short: "s", type: "boolean", description: "Explain staged changes (default)" },
    ],
    examples: [
      "gai explain",
      "gai explain --unstaged",
      "git diff main..feature | gai explain",
    ],
    handler: handleExplain,
  },

  {
    name: "review",
    aliases: ["r", "rv"],
    description: "AI code review of staged changes",
    usage: "gai review [--strict|--lenient] [--unstaged]",
    flags: [
      { long: "strict", type: "boolean", description: "Thorough review, flag minor issues" },
      { long: "lenient", type: "boolean", description: "Focus only on major issues" },
      { long: "unstaged", short: "u", type: "boolean", description: "Review unstaged changes instead of staged" },
    ],
    examples: [
      "gai review",
      "gai review --strict",
      "gai review --unstaged",
      "git diff main..feature | gai review",
    ],
    handler: handleReview,
  },

  {
    name: "changelog",
    aliases: ["cl", "log"],
    description: "Generate changelog from recent commits",
    usage: "gai changelog [--from <ref>] [--to <ref>] [--count <n>]",
    flags: [
      { long: "from", short: "f", type: "string", description: "Starting ref (tag or commit)" },
      { long: "to", short: "t", type: "string", description: "Ending ref (default: HEAD)" },
      { long: "count", short: "n", type: "string", description: "Number of recent commits (default: 20)" },
    ],
    examples: [
      "gai changelog",
      "gai changelog --from v1.0.0",
      "gai changelog --from v1.0.0 --to v1.1.0",
      "gai changelog -n 50",
    ],
    handler: handleChangelog,
  },

  {
    name: "suggest",
    aliases: ["sg"],
    description: "Suggest branch name or commit type based on changes",
    usage: "gai suggest [branch|type]",
    flags: [
      { long: "unstaged", short: "u", type: "boolean", description: "Use unstaged changes" },
    ],
    examples: [
      "gai suggest branch",
      "gai suggest type",
      "git diff | gai suggest branch",
    ],
    handler: handleSuggest,
  },
);

// Keep the defs accessible for help command
const allCommandDefs = [...commands.values()].filter(
  (c, i, arr) => arr.findIndex((x) => x.name === c.name) === i,
);

// ── Main ───────────────────────────────────────────────────────────────

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

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

// Initialize TTY detection early (before any command handlers run)
initTTY();

// Apply --no-color early
if (args.includes("--no-color")) {
  setColorEnabled(false);
}

runCLI(args, commands)
  .then((exitCode) => {
    process.exit(exitCode);
  })
  .catch((err) => {
    console.error(`\n  Unexpected error: ${err.message ?? err}\n`);
    process.exit(1);
  });