#!/usr/bin/env bash
# ==============================================================================
# Multi-Agent Mux (MAM) Skill Installer
# Efficiently installs MAM orchestration rules & skills to another project.
# ==============================================================================

set -euo pipefail

# ANSI color codes
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Helper functions for logs
log_info() { echo -e "${BLUE}[INFO]${NC} $*"; }
log_ok() { echo -e "${GREEN}[OK]${NC} $*"; }
log_warn() { echo -e "${YELLOW}[WARN]${NC} $*"; }
log_error() { echo -e "${RED}[ERROR]${NC} $*" >&2; }

show_help() {
  cat <<EOF
Usage: $0 [options]

Options:
  -t, --target <path>   Target directory/project where MAM should be installed (defaults to current directory)
  -f, --force           Force copy AGENTS.md even if it already exists (backups are still made)
  -h, --help            Show this help message
EOF
}

TARGET_DIR="."
FORCE=0

# Parse CLI arguments
while [[ $# -gt 0 ]]; do
  case "$1" in
    -t|--target)
      TARGET_DIR="$2"
      shift 2
      ;;
    -f|--force)
      FORCE=1
      shift
      ;;
    -h|--help)
      show_help
      exit 0
      ;;
    *)
      log_error "Unknown option: $1"
      show_help
      exit 1
      ;;
  esac
done

# Resolve absolute path for source and target, tracking symlinks gracefully
SOURCE="${BASH_SOURCE[0]}"
while [ -h "$SOURCE" ]; do
  DIR="$( cd -P "$( dirname "$SOURCE" )" >/dev/null 2>&1 && pwd )"
  SOURCE="$(readlink "$SOURCE")"
  [[ $SOURCE != /* ]] && SOURCE="$DIR/$SOURCE"
done
DIR="$( cd -P "$( dirname "$SOURCE" )" >/dev/null 2>&1 && pwd )"
SRC_DIR="$(cd "$DIR/.." && pwd)"
TARGET_DIR="$(mkdir -p "$TARGET_DIR" && cd "$TARGET_DIR" && pwd)"

log_info "Installing MAM skills to target project: $TARGET_DIR"
log_info "Source directory resolved: $SRC_DIR"

if [ "$SRC_DIR" = "$TARGET_DIR" ]; then
  log_error "Source and Target directories are the same! Cannot install to oneself."
  exit 1
fi

# 1. Dependency Checks
log_info "Verifying host dependencies..."
DEPS=(tmux python3 sqlite3 rsync)
MISSING_DEPS=()
for dep in "${DEPS[@]}"; do
  if ! command -v "$dep" &>/dev/null; then
    MISSING_DEPS+=("$dep")
  fi
done

if [ ${#MISSING_DEPS[@]} -ne 0 ]; then
  log_error "Missing required dependencies: ${MISSING_DEPS[*]}"
  log_error "Please install them before using MAM."
  exit 1
fi

# Check Python PyYAML library
if ! python3 -c "import yaml" &>/dev/null; then
  log_warn "Python 'pyyaml' package is not installed. Python YAML parsing features may fail."
  log_warn "Please run: pip install pyyaml"
fi
log_ok "Dependency checks completed."

# 2. Copy .agents/ folder
log_info "Deploying orchestration rules & skills (.agents/)..."
mkdir -p "$TARGET_DIR/.agents"

# Sync rules and skills, avoiding copying temporary or system files
# Exclude git histories or internal runtime cache if any
rsync -a --exclude='.git/' --exclude='reports/' --exclude='*.log' --exclude='__pycache__/' --exclude='*.pyc' "$SRC_DIR/.agents/" "$TARGET_DIR/.agents/"
log_ok "Deployed Rules and Skills under target's .agents/"

# 3. Copy AGENTS.md to root
log_info "Configuring developer guidelines (AGENTS.md)..."
if [ -f "$TARGET_DIR/AGENTS.md" ]; then
  if [ "$FORCE" -eq 1 ]; then
    log_warn "AGENTS.md already exists in target project. Backing up and overwriting..."
    cp "$TARGET_DIR/AGENTS.md" "$TARGET_DIR/AGENTS.md.bak.$(date +%s)"
    cp "$SRC_DIR/AGENTS.md" "$TARGET_DIR/AGENTS.md"
    log_ok "Guidelines overwritten successfully."
  else
    log_warn "AGENTS.md already exists in target. Skipping copy. Use -f/--force to overwrite."
  fi
else
  cp "$SRC_DIR/AGENTS.md" "$TARGET_DIR/AGENTS.md"
  log_ok "Guidelines AGENTS.md copied to project root."
fi

# 4. Gitignore adjustments
log_info "Registering runtime isolation blocks in .gitignore..."
GITIGNORE="$TARGET_DIR/.gitignore"
MAM_PATTERN="/.mam/"

if [ -f "$GITIGNORE" ]; then
  if grep -Fqx "$MAM_PATTERN" "$GITIGNORE"; then
    log_ok "/.mam/ already registered in target's .gitignore."
  else
    echo -e "\n# Multi-Agent Mux (MAM) runtime databases and isolation cache\n$MAM_PATTERN" >> "$GITIGNORE"
    log_ok "Appended /.mam/ registration to .gitignore."
  fi
else
  echo -e "# Multi-Agent Mux (MAM) runtime databases and isolation cache\n$MAM_PATTERN" > "$GITIGNORE"
  log_ok "Created .gitignore with /.mam/ exclusion."
fi

# 5. Initialize runtime reports folder
mkdir -p "$TARGET_DIR/.mam/reports"
log_ok "Initialized runtime structures."

# Done
log_ok "MAM Installation completed successfully!"
cat <<EOF

--------------------------------------------------------------------------------
💡 Quick Start Guide:
  1. Initialize a new isolated session:
     $ bash .agents/skills/multi-agent-mux-create/scripts/create_session.sh \\
         --workspace "$TARGET_DIR" --agent claude --role developer --isolate

  2. Attach to the running session:
     $ tmux -L multi-agent-mux attach -t <session_name>

  3. Gracefully stop the session:
     $ bash .agents/skills/multi-agent-mux-stop/scripts/stop_session.sh \\
         --session <session_name> --agent claude
--------------------------------------------------------------------------------
EOF