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

# mosaic — Unified agent launcher and management CLI
#
# AGENTS.md is the single source of truth for all agent sessions.
# The launcher injects it into every runtime consistently.
#
# Usage:
#   mosaic claude [args...]       Launch Claude Code with AGENTS.md injected
#   mosaic opencode [args...]     Launch OpenCode with AGENTS.md injected
#   mosaic codex [args...]        Launch Codex with AGENTS.md injected
#   mosaic init [args...]         Generate SOUL.md interactively
#   mosaic doctor [args...]       Health audit
#   mosaic sync [args...]         Sync skills
#   mosaic bootstrap <path>       Bootstrap a repo

MOSAIC_HOME="${MOSAIC_HOME:-$HOME/.config/mosaic}"
VERSION="0.1.0"

usage() {
  cat <<USAGE
mosaic $VERSION — Unified agent launcher

Usage: mosaic <command> [args...]

Agent Launchers:
  claude [args...]       Launch Claude Code with AGENTS.md injected
  opencode [args...]     Launch OpenCode with AGENTS.md injected
  codex [args...]        Launch Codex with AGENTS.md injected

Management:
  init [args...]         Generate SOUL.md (agent identity contract)
  doctor [args...]       Audit runtime state and detect drift
  sync [args...]         Sync skills from canonical source
  bootstrap <path>       Bootstrap a repo with Mosaic standards

Options:
  -h, --help             Show this help
  -v, --version          Show version

All arguments after the command are forwarded to the target CLI.
USAGE
}

# Pre-flight checks
check_mosaic_home() {
  if [[ ! -d "$MOSAIC_HOME" ]]; then
    echo "[mosaic] ERROR: ~/.config/mosaic not found." >&2
    echo "[mosaic] Install with: curl -sL https://git.mosaicstack.dev/mosaic/bootstrap/raw/branch/main/remote-install.sh | sh" >&2
    exit 1
  fi
}

check_agents_md() {
  if [[ ! -f "$MOSAIC_HOME/AGENTS.md" ]]; then
    echo "[mosaic] ERROR: ~/.config/mosaic/AGENTS.md not found." >&2
    echo "[mosaic] Re-run the installer: cd ~/src/mosaic-bootstrap && bash install.sh" >&2
    exit 1
  fi
}

check_soul() {
  if [[ ! -f "$MOSAIC_HOME/SOUL.md" ]]; then
    echo "[mosaic] SOUL.md not found. Running mosaic init..."
    "$MOSAIC_HOME/bin/mosaic-init"
  fi
}

check_runtime() {
  local cmd="$1"
  if ! command -v "$cmd" >/dev/null 2>&1; then
    echo "[mosaic] ERROR: '$cmd' not found in PATH." >&2
    echo "[mosaic] Install $cmd before launching." >&2
    exit 1
  fi
}

# Ensure AGENTS.md is present at the runtime's native config path.
# Used for runtimes that don't support CLI prompt injection.
ensure_runtime_config() {
  local src="$MOSAIC_HOME/AGENTS.md"
  local dst="$1"
  mkdir -p "$(dirname "$dst")"
  if ! cmp -s "$src" "$dst" 2>/dev/null; then
    cp "$src" "$dst"
  fi
}

# Launcher functions
launch_claude() {
  check_mosaic_home
  check_agents_md
  check_soul
  check_runtime "claude"

  # Claude supports --append-system-prompt for direct injection
  local agents_content
  agents_content="$(cat "$MOSAIC_HOME/AGENTS.md")"
  echo "[mosaic] Launching Claude Code..."
  exec claude --append-system-prompt "$agents_content" "$@"
}

launch_opencode() {
  check_mosaic_home
  check_agents_md
  check_soul
  check_runtime "opencode"

  # OpenCode reads from ~/.config/opencode/AGENTS.md — copy canonical version there
  ensure_runtime_config "$HOME/.config/opencode/AGENTS.md"
  echo "[mosaic] Launching OpenCode..."
  exec opencode "$@"
}

launch_codex() {
  check_mosaic_home
  check_agents_md
  check_soul
  check_runtime "codex"

  # Codex reads from ~/.codex/instructions.md — copy canonical version there
  ensure_runtime_config "$HOME/.codex/instructions.md"
  echo "[mosaic] Launching Codex..."
  exec codex "$@"
}

# Delegate to existing scripts
run_init() {
  check_mosaic_home
  exec "$MOSAIC_HOME/bin/mosaic-init" "$@"
}

run_doctor() {
  check_mosaic_home
  exec "$MOSAIC_HOME/bin/mosaic-doctor" "$@"
}

run_sync() {
  check_mosaic_home
  exec "$MOSAIC_HOME/bin/mosaic-sync-skills" "$@"
}

run_bootstrap() {
  check_mosaic_home
  exec "$MOSAIC_HOME/bin/mosaic-bootstrap-repo" "$@"
}

# Main router
if [[ $# -eq 0 ]]; then
  usage
  exit 0
fi

command="$1"
shift

case "$command" in
  claude)     launch_claude "$@" ;;
  opencode)   launch_opencode "$@" ;;
  codex)      launch_codex "$@" ;;
  init)       run_init "$@" ;;
  doctor)     run_doctor "$@" ;;
  sync)       run_sync "$@" ;;
  bootstrap)  run_bootstrap "$@" ;;
  help|-h|--help)  usage ;;
  version|-v|--version) echo "mosaic $VERSION" ;;
  *)
    echo "[mosaic] Unknown command: $command" >&2
    echo "[mosaic] Run 'mosaic --help' for usage." >&2
    exit 1
    ;;
esac