#!/usr/bin/env bash
# install.sh — bootstrap installer for the skills library.
#
# Usage (one-liner, hosts without Task):
#   curl -fsSL https://git.d-ma.be/mathias/skills/raw/branch/main/install.sh | bash
#
# Pinned to a specific tag:
#   SKILLS_REF=v0.4.0 bash install.sh
#
# Idempotent: re-running pulls the latest changes for the configured ref
# (default: main) and re-wires the links.
#
# Claude Code is NOT wired here. It installs this repo as a plugin from the
# marketplace this repo also hosts:
#
#   /plugin marketplace add https://git.d-ma.be/mathias/skills.git
#   /plugin install skills@mathias
#
# That path carries the hooks and MCP server definitions too, which symlinks
# cannot. This script covers the harnesses with no plugin system: Crush, Pi
# and OpenCode.
#
# Wiring model — one directory link per harness, never one per skill:
#
#   ~/.agents/skills            -> $CHECKOUT_DIR/skills   (canonical; Pi reads it directly)
#   ~/.config/crush/skills      -> ~/.agents/skills
#   ~/.config/opencode/skills   -> ~/.agents/skills
#
# Adding a skill to the repo therefore wires it everywhere with no re-run,
# and a broken link is one broken link rather than 42.
#
# CHECKOUT_DIR deliberately defaults OUTSIDE any file-synced or
# cross-platform-shared directory. Do not "fix" it to point into ~/dev: on a
# fleet whose workspace is shared between macOS (/Users/...) and Linux
# (/home/...), an absolute link stored there is broken on one side by
# construction. See mathias/skills#23.

set -euo pipefail

REPO_URL="${SKILLS_REPO_URL:-https://git.d-ma.be/mathias/skills.git}"
REF="${SKILLS_REF:-main}"
CHECKOUT_DIR="${SKILLS_CHECKOUT_DIR:-$HOME/.local/share/skills}"
AGENTS_DIR="${AGENTS_SKILLS_DIR:-$HOME/.agents/skills}"
CRUSH_DIR="${CRUSH_SKILLS_DIR:-$HOME/.config/crush/skills}"
OPENCODE_DIR="${OPENCODE_SKILLS_DIR:-$HOME/.config/opencode/skills}"

log() { printf '[skills] %s\n' "$*"; }

ensure_checkout() {
  # Wiring an existing working checkout (task install) must not fetch or
  # move HEAD — that would discard in-progress work.
  if [ "${SKILLS_SKIP_FETCH:-}" = "1" ]; then
    [ -d "$CHECKOUT_DIR/skills" ] || { log "no skills/ under $CHECKOUT_DIR"; exit 1; }
    log "using $CHECKOUT_DIR as-is (SKILLS_SKIP_FETCH=1)"
    return
  fi
  if [ -d "$CHECKOUT_DIR/.git" ]; then
    log "updating $CHECKOUT_DIR"
    git -C "$CHECKOUT_DIR" fetch --tags --quiet
    git -C "$CHECKOUT_DIR" checkout --quiet "$REF"
    if git -C "$CHECKOUT_DIR" symbolic-ref -q HEAD >/dev/null; then
      # on a branch — fast-forward
      git -C "$CHECKOUT_DIR" pull --ff-only --quiet
    fi
  else
    log "cloning $REPO_URL into $CHECKOUT_DIR (ref=$REF)"
    mkdir -p "$(dirname "$CHECKOUT_DIR")"
    git clone --quiet "$REPO_URL" "$CHECKOUT_DIR"
    git -C "$CHECKOUT_DIR" checkout --quiet "$REF"
  fi
}

count_skills() {
  find "$CHECKOUT_DIR/skills" -mindepth 2 -maxdepth 2 -name SKILL.md 2>/dev/null | wc -l | tr -d ' '
}

# link_dir <link_path> <target_path>
# Replaces whatever is there — including a directory left behind by the old
# per-skill wiring — with a single symlink.
link_dir() {
  local link="$1" target="$2"
  if [ -L "$link" ]; then
    [ "$(readlink "$link")" = "$target" ] && return
    rm -f "$link"
  elif [ -d "$link" ]; then
    # Refuse to discard a directory holding anything but symlinks: that
    # would be someone's real skills, not our old wiring.
    if find "$link" -mindepth 1 -maxdepth 1 ! -type l | grep -q .; then
      log "REFUSING to replace $link — it holds non-symlink entries; move them and re-run"
      return 1
    fi
    find "$link" -mindepth 1 -maxdepth 1 -type l -delete
    rmdir "$link"
  elif [ -e "$link" ]; then
    rm -f "$link"
  fi
  mkdir -p "$(dirname "$link")"
  ln -s "$target" "$link"
  log "linked $link → $target"
}

main() {
  ensure_checkout

  # Canonical location. Pi reads ~/.agents/skills directly, so it needs no
  # harness-specific link of its own.
  link_dir "$AGENTS_DIR" "$CHECKOUT_DIR/skills"

  link_dir "$CRUSH_DIR" "$AGENTS_DIR"
  link_dir "$OPENCODE_DIR" "$AGENTS_DIR"

  log "done — $(count_skills) skill(s) at ref=$REF, 3 links total"
  log "Claude Code: install the plugin instead — /plugin marketplace add $REPO_URL"
}

main "$@"