ai-tools.sh

#!/usr/bin/env bash
set -euo pipefail

usage() {
  cat <<'USAGE'
Usage: ai-tools.sh --tool <codex|opencode|gemini> [options] [prompt...]

Options:
  -t, --tool <name>       Target CLI to invoke (required).
  -p, --prompt <text>     Add prompt text; can be provided multiple times.
  -f, --file <path(s)>    Inline file contents; repeatable or comma-separated list.
      --model <name>      Override default model (currently opencode only).
  -h, --help              Show this message.

If stdin is provided, it is appended to the prompt as an additional block.
Example:
  ai-agent.sh -t opencode -p "Summarize" -f src/main.py
USAGE
}

error() {
  echo "Error: $*" >&2
  exit 1
}

trim() {
  local var="$1"
  var="${var#${var%%[![:space:]]*}}"
  var="${var%${var##*[![:space:]]}}"
  printf '%s' "$var"
}

ensure_cmd() {
  if ! command -v "$1" >/dev/null 2>&1; then
    error "Required command '$1' is not available in PATH."
  fi
}

read_env_var() {
  local key="$1"
  local env_file="${ENV_FILE:-$HOME/.env}"
  [[ -f "$env_file" ]] || return 1

  local line value
  line=$(grep -E "^(export )?${key}=" "$env_file" | tail -n 1 || true)
  [[ -n "$line" ]] || return 1

  value="${line#*=}"
  value="${value%\r}"
  value="${value%\n}"
  value="${value#\"}"
  value="${value%\"}"
  echo "$value"
}

append_block() {
  local content="$1"
  [[ -z "$content" ]] && return
  if [[ -n "${prompt_payload:-}" ]]; then
    prompt_payload+=$'\n\n'
  fi
  prompt_payload+="$content"
}

prompt_parts=()
files=()
model_override=""
tool=""

while [[ $# -gt 0 ]]; do
  case "$1" in
  -t | --tool)
    [[ $# -ge 2 ]] || error "--tool requires a value"
    tool="$2"
    shift 2
    ;;
  -p | --prompt)
    [[ $# -ge 2 ]] || error "--prompt requires a value"
    prompt_parts+=("$2")
    shift 2
    ;;
  -f | --file)
    [[ $# -ge 2 ]] || error "--file requires a path"
    IFS=',' read -r -a raw_files <<<"$2"
    for entry in "${raw_files[@]}"; do
      trimmed=$(trim "$entry")
      [[ -z "$trimmed" ]] && continue
      if [[ $trimmed == ~* ]]; then
        trimmed="${trimmed/#\~/$HOME}"
      fi
      files+=("$trimmed")
    done
    shift 2
    ;;
  --model)
    [[ $# -ge 2 ]] || error "--model requires a value"
    model_override="$2"
    shift 2
    ;;
  -h | --help)
    usage
    exit 0
    ;;
  --)
    shift
    while [[ $# -gt 0 ]]; do
      prompt_parts+=("$1")
      shift
    done
    ;;
  *)
    prompt_parts+=("$1")
    shift
    ;;
  esac
done

[[ -n "$tool" ]] || error "--tool is required"
tool=$(echo "$tool" | tr '[:upper:]' '[:lower:]')

prompt_payload=""
if [[ ${#prompt_parts[@]} -gt 0 ]]; then
  append_block "$(printf '%s' "${prompt_parts[*]}")"
fi

if [[ ! -t 0 ]]; then
  stdin_input=$(cat)
  append_block "stdin:\n${stdin_input}"
fi

if ((${#files[@]})); then
  for file in "${files[@]}"; do
    [[ -r "$file" ]] || error "File '$file' not found or not readable"
    file_block=$'File: '
    file_block+="$file"
    file_block+=$'\n```\n'
    file_block+=$(<"$file")
    file_block+=$'\n```'
    append_block "$file_block"
  done
fi

[[ -n "$prompt_payload" ]] || error "Prompt is empty; provide --prompt, positional text, stdin, or --file"

case "$tool" in
codex)
  if /bin/zsh -lic 'command -v cdx >/dev/null' >/dev/null 2>&1; then
    PROMPT_PAYLOAD="$prompt_payload" exec /bin/zsh -lic 'cdx exec "$PROMPT_PAYLOAD"'
  fi
  ensure_cmd codex
  exec codex exec "$prompt_payload"
  ;;
opencode)
  ensure_cmd opencode
  model_value="${model_override:-openrouter/x-ai/grok-4-fast:free}"
  exec opencode run --model "$model_value" "$prompt_payload"
  ;;
claude)
  ensure_cmd claude
  exec claude --dangerously-skip-permissions -p "$prompt_payload"
  ;;
gemini)
  ensure_cmd gemini
  model_value="${model_override:-gemini-2.5-pro}"
  exec gemini --model "$model_value" -p "$prompt_payload"
  ;;
*)
  error "Unsupported tool '$tool'."
  ;;
esac