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

usage() {
  cat <<EOF
Usage: new-plugin.sh <plugin-name> <repo-root>

Scaffold a new plugin directory with both manifests and skeleton dirs.

Arguments:
  plugin-name  Kebab-case plugin identifier (e.g. my-tools, data-tools).
               Must be lowercase letters, numbers, and hyphens only.
               No leading, trailing, or consecutive hyphens.
  repo-root    Absolute or relative path to the repository root.
               The plugin is created at <repo-root>/plugins/<plugin-name>/.

Created structure:
  <repo-root>/plugins/<plugin-name>/
    plugin.json                     Copilot CLI manifest (FILL_IN_* placeholders)
    .claude-plugin/
      plugin.json                   Claude Code manifest (FILL_IN_* placeholders)
    skills/                         Empty skeleton directory
    agents/                         Empty skeleton directory
    hooks/                          Empty skeleton directory
    bin/                            Empty skeleton directory

Each file and directory is a no-op if it already exists.
Does NOT touch marketplace.json.

Exit codes:
  0  Files created or already existed (no-op)
  1  Invalid arguments or missing root
EOF
}

if [[ "${1:-}" == "--help" || "${1:-}" == "-h" ]]; then
  usage
  exit 0
fi

if [[ $# -lt 2 ]]; then
  echo "Error: plugin-name and repo-root are required." >&2
  echo "" >&2
  usage >&2
  exit 1
fi

PLUGIN_NAME="$1"
REPO_ROOT="$2"

# Validate plugin name format
if ! echo "$PLUGIN_NAME" | grep -qE '^[a-z0-9]+(-[a-z0-9]+)*$'; then
  echo "Error: plugin-name must use lowercase letters, numbers, and hyphens only." >&2
  echo "       No leading, trailing, or consecutive hyphens." >&2
  echo "       Received: '$PLUGIN_NAME'" >&2
  exit 1
fi

# Expand tilde
REPO_ROOT="${REPO_ROOT/#\~/$HOME}"

# Resolve to absolute path
REPO_ROOT="$(cd "$REPO_ROOT" 2>/dev/null && pwd)" || {
  echo "Error: repo-root directory '$2' does not exist." >&2
  exit 1
}

PLUGIN_DIR="$REPO_ROOT/plugins/$PLUGIN_NAME"
CC_DIR="$PLUGIN_DIR/.claude-plugin"
COPILOT_MANIFEST="$PLUGIN_DIR/plugin.json"
CC_MANIFEST="$CC_DIR/plugin.json"

# Create directory skeleton
created_any=false

create_dir_if_missing() {
  local dir="$1"
  if [[ -d "$dir" ]]; then
    echo "Skipping directory '$dir' — already exists." >&2
  else
    mkdir -p "$dir"
    echo "Created directory: $dir" >&2
    created_any=true
  fi
}

create_dir_if_missing "$PLUGIN_DIR"
create_dir_if_missing "$CC_DIR"
create_dir_if_missing "$PLUGIN_DIR/skills"
create_dir_if_missing "$PLUGIN_DIR/agents"
create_dir_if_missing "$PLUGIN_DIR/hooks"
create_dir_if_missing "$PLUGIN_DIR/bin"

# Create Copilot manifest (plugin.json)
if [[ -f "$COPILOT_MANIFEST" ]]; then
  echo "Skipping '$COPILOT_MANIFEST' — already exists." >&2
else
  cat > "$COPILOT_MANIFEST" <<COPILOT_JSON
{
  "name": "$PLUGIN_NAME",
  "description": "FILL_IN_DESCRIPTION",
  "version": "1.0.0",
  "author": { "name": "FILL_IN_AUTHOR_NAME", "email": "FILL_IN_AUTHOR_EMAIL" },
  "license": "MIT",
  "keywords": [],
  "agents": "agents/",
  "skills": ["skills/"],
  "hooks": "hooks.json",
  "mcpServers": ".mcp.json"
}
COPILOT_JSON
  echo "Created: $COPILOT_MANIFEST" >&2
  created_any=true
fi

# Create Claude Code manifest (.claude-plugin/plugin.json)
if [[ -f "$CC_MANIFEST" ]]; then
  echo "Skipping '$CC_MANIFEST' — already exists." >&2
else
  cat > "$CC_MANIFEST" <<CC_JSON
{
  "name": "$PLUGIN_NAME",
  "displayName": "FILL_IN_DISPLAY_NAME",
  "description": "FILL_IN_DESCRIPTION",
  "version": "1.0.0",
  "author": { "name": "FILL_IN_AUTHOR_NAME", "url": "FILL_IN_AUTHOR_URL" },
  "license": "MIT",
  "keywords": []
}
CC_JSON
  echo "Created: $CC_MANIFEST" >&2
  created_any=true
fi

if [[ "$created_any" == false ]]; then
  echo "All files already exist — nothing to do." >&2
else
  echo "" >&2
  echo "Plugin: $PLUGIN_NAME" >&2
  echo "Location: $PLUGIN_DIR" >&2
  echo "" >&2
  echo "Next steps:" >&2
  echo "  1. Fill in $COPILOT_MANIFEST — replace all FILL_IN_* placeholders" >&2
  echo "  2. Fill in $CC_MANIFEST — replace all FILL_IN_* placeholders" >&2
  echo "  3. Verify version is identical in both manifests (version parity — ADR-0016)" >&2
  echo "  4. Add plugin content: skills in skills/, agents in agents/, etc." >&2
fi