/**
 * Shell integration for jack cd/new/clone to auto-change directories.
 * Shell function lives in ~/.config/jack/shell.sh, sourced from rc file.
 * jack update regenerates the managed file.
 */

import { appendFileSync, existsSync, mkdirSync, readFileSync, writeFileSync } from "node:fs";
import { homedir } from "node:os";
import { dirname, join } from "node:path";
import pkg from "../../package.json";

type Shell = "bash" | "zsh" | "unknown";

// Markers for detection
const LEGACY_MARKER = "# jack shell integration";
const SOURCE_LINE_MARKER = "# jack: shell integration (do not edit)";

export function getShellFilePath(): string {
	return join(homedir(), ".config", "jack", "shell.sh");
}

export function getSourceLine(): string {
	const shellFile = getShellFilePath();
	return `${SOURCE_LINE_MARKER}\n[ -f "${shellFile}" ] && source "${shellFile}"`;
}

function getShellFunction(): string {
	return `# jack shell integration v${pkg.version}
# This file is managed by jack. Do not edit manually.
# It will be regenerated by 'jack update'.

jack() {
  case "$1" in
    cd)
      # Get project path and cd to it
      local dir
      dir="$(command jack cd "\${@:2}" 2>/dev/null)"
      if [[ -n "$dir" && -d "$dir" ]]; then
        cd "$dir" || return 1
      else
        # Show error output if cd failed
        command jack cd "\${@:2}"
      fi
      ;;
    new|clone)
      # Run the command, capture stdout (project path) while showing stderr
      local dir
      dir="$(command jack "$@")"
      local exit_code=$?
      if [[ $exit_code -eq 0 && -n "$dir" && -d "$dir" ]]; then
        cd "$dir" || return $exit_code
      fi
      return $exit_code
      ;;
    "")
      # No args: interactive picker - cd if it outputs a directory
      local output
      output="$(command jack)"
      if [[ -n "$output" && -d "$output" ]]; then
        cd "$output" || return 1
      elif [[ -n "$output" ]]; then
        # Not a directory (e.g., help text) - show it
        echo "$output"
      fi
      ;;
    *)
      # Pass through all other commands
      command jack "$@"
      ;;
  esac
}`;
}

export function detectShell(): Shell {
	const shell = process.env.SHELL || "";
	if (shell.endsWith("/bash") || shell.endsWith("/bash5")) return "bash";
	if (shell.endsWith("/zsh")) return "zsh";
	return "unknown";
}

export function getRcFilePath(shell: Shell): string | null {
	const home = homedir();

	switch (shell) {
		case "zsh":
			return join(home, ".zshrc");
		case "bash": {
			// Prefer .bashrc, fall back to .bash_profile on macOS
			const bashrc = join(home, ".bashrc");
			const profile = join(home, ".bash_profile");
			if (existsSync(bashrc)) return bashrc;
			if (existsSync(profile)) return profile;
			// Default to .bashrc (will be created)
			return bashrc;
		}
		default:
			return null;
	}
}

export function isInstalled(rcFile: string): boolean {
	if (!existsSync(rcFile)) return false;

	try {
		const content = readFileSync(rcFile, "utf-8");
		return content.includes(SOURCE_LINE_MARKER);
	} catch {
		return false;
	}
}

export function hasLegacyInstall(rcFile: string): boolean {
	if (!existsSync(rcFile)) return false;

	try {
		const content = readFileSync(rcFile, "utf-8");
		// Has old marker but not new source line
		return content.includes(LEGACY_MARKER) && !content.includes(SOURCE_LINE_MARKER);
	} catch {
		return false;
	}
}

export function removeLegacyInstall(rcFile: string): void {
	if (!existsSync(rcFile)) return;

	const content = readFileSync(rcFile, "utf-8");

	const legacyPattern = /\n?# jack shell integration\njack\(\) \{[\s\S]*?\n\}\n?/g;

	const newContent = content.replace(legacyPattern, "\n");

	writeFileSync(rcFile, newContent, "utf-8");
}

export function writeShellFile(): void {
	const shellFile = getShellFilePath();
	const dir = dirname(shellFile);

	mkdirSync(dir, { recursive: true });
	writeFileSync(shellFile, getShellFunction(), "utf-8");
}

export function addSourceLine(rcFile: string): void {
	const sourceLine = getSourceLine();
	appendFileSync(rcFile, `\n${sourceLine}\n`, "utf-8");
}

export function install(rcFile: string): { migrated: boolean } {
	let migrated = false;

	if (hasLegacyInstall(rcFile)) {
		removeLegacyInstall(rcFile);
		migrated = true;
	}

	writeShellFile();
	if (!isInstalled(rcFile)) {
		addSourceLine(rcFile);
	}

	return { migrated };
}

export function update(): void {
	writeShellFile();
}

export function getShellCode(): string {
	return getShellFunction();
}

export function getShellName(shell: Shell): string {
	switch (shell) {
		case "bash":
			return "Bash";
		case "zsh":
			return "Zsh";
		default:
			return "your shell";
	}
}

export function getRcFileName(rcFile: string): string {
	return rcFile.split("/").pop() || rcFile;
}

export function getShellFileDisplayPath(): string {
	return "~/.config/jack/shell.sh";
}