#!/bin/sh
# LenderSkills installer — https://lenderskills.ai
#
# Usage:  curl -fsSL https://lenderskills.ai/cli | sh -s -- <skill-slug> [install-key]
#         curl -fsSL https://lenderskills.ai/cli | sh -s -- kit:<kit-slug> [install-key]
#         curl -fsSL https://lenderskills.ai/cli | sh -s -- agent:<agent-slug> [install-key]
#
# Writes .claude/skills/<slug>/SKILL.md in the current directory — one folder
# per skill, or one per skill in the kit. Your install key is on any skill page
# once you are signed in, and at https://lenderskills.ai/install. Without one the exchange
# cannot tell the author who downloaded their work, which is the only thing
# they are paid in. A kit installs each skill through its own link, so every
# author in it is told, exactly as if you had installed that skill alone.
# An agent writes .claude/agents/<slug>.md plus every skill it runs, the same way.
set -eu

ARG="${1:-}"
KEY="${2:-${LENDERSKILLS_KEY:-}}"

if [ -z "$ARG" ]; then
  echo "usage: curl -fsSL https://lenderskills.ai/cli | sh -s -- <skill-slug> [install-key]" >&2
  echo "       curl -fsSL https://lenderskills.ai/cli | sh -s -- kit:<kit-slug> [install-key]" >&2
  echo "       curl -fsSL https://lenderskills.ai/cli | sh -s -- agent:<agent-slug> [install-key]" >&2
  echo "browse the catalogue at https://lenderskills.ai/, the kits at https://lenderskills.ai/kits/ and the agents at https://lenderskills.ai/agents/" >&2
  exit 2
fi

TMP="$(mktemp)"
trap 'rm -f "$TMP"' EXIT INT TERM

# A slug is lowercase letters, digits and hyphens. Anything else is either a
# typo or an attempt to reach outside the catalogue, and both end here.
valid() {
  case "$1" in
    *[!a-z0-9-]*|"") return 1 ;;
  esac
  return 0
}

# Install one skill. Returns non-zero on failure rather than exiting, so a kit
# can report every skill that did not make it instead of stopping at the first.
install_one() {
  SLUG="$1"
  if ! valid "$SLUG"; then
    echo "lenderskills: '$SLUG' is not a valid skill slug." >&2
    return 2
  fi

  URL="https://lenderskills.ai/i/${SLUG}?raw=1"
  [ -n "$KEY" ] && URL="${URL}&k=${KEY}"
  DIR=".claude/skills/${SLUG}"

  # -f so an HTTP error is a failure rather than a file full of error text.
  if ! curl -fsSL "$URL" -o "$TMP"; then
    echo "lenderskills: could not fetch '$SLUG'." >&2
    echo "  - check the slug at https://lenderskills.ai/skill/${SLUG}/" >&2
    echo "  - if you passed no key, sign in at https://lenderskills.ai/install to get one" >&2
    return 1
  fi

  # The gate document is prose, not a skill file. Recognise it rather than
  # writing it to disk and leaving someone with a broken skill.
  if head -n 1 "$TMP" | grep -q '^LENDERSKILLS — THIS INSTALL NEEDS'; then
    echo "lenderskills: '$SLUG' needs your free install key." >&2
    echo "  get one at https://lenderskills.ai/install, then run the same command with it on the end." >&2
    return 1
  fi

  if [ ! -s "$TMP" ]; then
    echo "lenderskills: '$SLUG' came back empty. Try https://lenderskills.ai/skill/${SLUG}/." >&2
    return 1
  fi

  if [ -f "${DIR}/SKILL.md" ]; then
    echo "lenderskills: ${DIR}/SKILL.md already exists — overwriting with the current version."
  fi

  mkdir -p "$DIR"
  cat "$TMP" > "${DIR}/SKILL.md"

  # Errors keep the lowercase "lenderskills:" prefix a unix tool is expected to
  # use. Success is the one line worth signing properly.
  echo "LenderSkills — installed ${SLUG} → ${DIR}/SKILL.md"
  return 0
}

case "$ARG" in
  kit:*)
    KIT="${ARG#kit:}"
    if ! valid "$KIT"; then
      echo "lenderskills: '$KIT' is not a valid kit name. See https://lenderskills.ai/kits/" >&2
      exit 2
    fi
    if [ -z "$KEY" ]; then
      echo "lenderskills: a kit needs your free install key." >&2
      echo "  get one at https://lenderskills.ai/install, then:" >&2
      echo "  curl -fsSL https://lenderskills.ai/cli | sh -s -- kit:$KIT <your-key>" >&2
      exit 1
    fi
    LIST="$(mktemp)"
    trap 'rm -f "$TMP" "$LIST"' EXIT INT TERM
    if ! curl -fsSL "https://lenderskills.ai/k/${KIT}?list=1" -o "$LIST"; then
      echo "lenderskills: no starter kit called '$KIT'. See https://lenderskills.ai/kits/" >&2
      exit 1
    fi
    OK=0; FAILED=""
    while IFS= read -r S; do
      [ -z "$S" ] && continue
      if install_one "$S"; then OK=$((OK + 1)); else FAILED="$FAILED $S"; fi
    done < "$LIST"
    echo
    echo "LenderSkills — $OK skills installed from the $KIT kit."
    if [ -n "$FAILED" ]; then
      echo "lenderskills: these did not install:$FAILED" >&2
      echo "  retry one with: curl -fsSL https://lenderskills.ai/cli | sh -s -- <skill-slug> <your-key>" >&2
    fi
    echo
    echo "Next: fill in every [BRACKETED] placeholder with your firm's own values,"
    echo "or ask your assistant to walk you through them across the whole kit."
    echo "Kit: https://lenderskills.ai/kit/${KIT}/"
    [ -z "$FAILED" ] || exit 1
    ;;
  agent:*)
    AGENT="${ARG#agent:}"
    if ! valid "$AGENT"; then
      echo "lenderskills: '$AGENT' is not a valid agent name. See https://lenderskills.ai/agents/" >&2
      exit 2
    fi
    if [ -z "$KEY" ]; then
      echo "lenderskills: an agent needs your free install key." >&2
      echo "  get one at https://lenderskills.ai/install, then:" >&2
      echo "  curl -fsSL https://lenderskills.ai/cli | sh -s -- agent:$AGENT <your-key>" >&2
      exit 1
    fi
    LIST="$(mktemp)"
    trap 'rm -f "$TMP" "$LIST"' EXIT INT TERM
    if ! curl -fsSL "https://lenderskills.ai/a/${AGENT}?list=1" -o "$LIST"; then
      echo "lenderskills: no agent called '$AGENT'. See https://lenderskills.ai/agents/" >&2
      exit 1
    fi
    if ! curl -fsSL "https://lenderskills.ai/a/${AGENT}?raw=1&k=${KEY}" -o "$TMP"       || head -n 1 "$TMP" | grep -q '^LENDERSKILLS — THIS INSTALL NEEDS'       || [ ! -s "$TMP" ]; then
      echo "lenderskills: could not fetch the '$AGENT' agent file." >&2
      echo "  check your key at https://lenderskills.ai/install and try again." >&2
      exit 1
    fi
    mkdir -p .claude/agents
    cat "$TMP" > ".claude/agents/${AGENT}.md"
    echo "LenderSkills — installed agent ${AGENT} → .claude/agents/${AGENT}.md"
    OK=0; FAILED=""
    while IFS= read -r S; do
      [ -z "$S" ] && continue
      if install_one "$S"; then OK=$((OK + 1)); else FAILED="$FAILED $S"; fi
    done < "$LIST"
    echo
    echo "LenderSkills — the $AGENT agent and $OK of its skills are installed."
    if [ -n "$FAILED" ]; then
      echo "lenderskills: these skills did not install:$FAILED" >&2
      echo "  the agent runs a reduced version of any skill that is missing." >&2
      echo "  retry one with: curl -fsSL https://lenderskills.ai/cli | sh -s -- <skill-slug> <your-key>" >&2
    fi
    echo
    echo "Next: restart Claude Code so it picks up the agent, then fill in every"
    echo "[BRACKETED] placeholder with your firm's own values."
    echo "Agent: https://lenderskills.ai/agent/${AGENT}/"
    [ -z "$FAILED" ] || exit 1
    ;;
  *)
    install_one "$ARG" || exit $?
    echo
    echo "Next: open the file and fill in every [BRACKETED] placeholder with your"
    echo "firm's own values, or ask your assistant to walk you through them."
    echo "Listing: https://lenderskills.ai/skill/${ARG}/"
    ;;
esac