#!/usr/bin/env bash
# gstack setup — build browser binary + register skills with Claude Code / Codex
set -e

if ! command -v bun >/dev/null 2>&1; then
  echo "Error: bun is required but not installed." >&2
  echo "Install it: curl -fsSL https://bun.sh/install | bash" >&2
  exit 1
fi

GSTACK_DIR="$(cd "$(dirname "$0")" && pwd)"
SKILLS_DIR="$(dirname "$GSTACK_DIR")"
BROWSE_BIN="$GSTACK_DIR/browse/dist/browse"

# ─── Parse --host flag ─────────────────────────────────────────
HOST="claude"
while [ $# -gt 0 ]; do
  case "$1" in
    --host) HOST="$2"; shift 2 ;;
    --host=*) HOST="${1#--host=}"; shift ;;
    *) shift ;;
  esac
done

case "$HOST" in
  claude|codex|auto) ;;
  *) echo "Unknown --host value: $HOST (expected claude, codex, or auto)" >&2; exit 1 ;;
esac

# For auto: detect which agents are installed
INSTALL_CLAUDE=0
INSTALL_CODEX=0
if [ "$HOST" = "auto" ]; then
  command -v claude >/dev/null 2>&1 && INSTALL_CLAUDE=1
  command -v codex >/dev/null 2>&1 && INSTALL_CODEX=1
  # If neither found, default to claude
  if [ "$INSTALL_CLAUDE" -eq 0 ] && [ "$INSTALL_CODEX" -eq 0 ]; then
    INSTALL_CLAUDE=1
  fi
elif [ "$HOST" = "claude" ]; then
  INSTALL_CLAUDE=1
elif [ "$HOST" = "codex" ]; then
  INSTALL_CODEX=1
fi

ensure_playwright_browser() {
  (
    cd "$GSTACK_DIR"
    bun --eval 'import { chromium } from "playwright"; const browser = await chromium.launch(); await browser.close();'
  ) >/dev/null 2>&1
}

# 1. Build browse binary if needed (smart rebuild: stale sources, package.json, lock)
NEEDS_BUILD=0
if [ ! -x "$BROWSE_BIN" ]; then
  NEEDS_BUILD=1
elif [ -n "$(find "$GSTACK_DIR/browse/src" -type f -newer "$BROWSE_BIN" -print -quit 2>/dev/null)" ]; then
  NEEDS_BUILD=1
elif [ "$GSTACK_DIR/package.json" -nt "$BROWSE_BIN" ]; then
  NEEDS_BUILD=1
elif [ -f "$GSTACK_DIR/bun.lock" ] && [ "$GSTACK_DIR/bun.lock" -nt "$BROWSE_BIN" ]; then
  NEEDS_BUILD=1
fi

if [ "$NEEDS_BUILD" -eq 1 ]; then
  echo "Building browse binary..."
  (
    cd "$GSTACK_DIR"
    bun install
    bun run build
  )
  # Safety net: write .version if build script didn't (e.g., git not available during build)
  if [ ! -f "$GSTACK_DIR/browse/dist/.version" ]; then
    git -C "$GSTACK_DIR" rev-parse HEAD > "$GSTACK_DIR/browse/dist/.version" 2>/dev/null || true
  fi
fi

if [ ! -x "$BROWSE_BIN" ]; then
  echo "gstack setup failed: browse binary missing at $BROWSE_BIN" >&2
  exit 1
fi

# 2. Ensure Playwright's Chromium is available
if ! ensure_playwright_browser; then
  echo "Installing Playwright Chromium..."
  (
    cd "$GSTACK_DIR"
    bunx playwright install chromium
  )
fi

if ! ensure_playwright_browser; then
  echo "gstack setup failed: Playwright Chromium could not be launched" >&2
  exit 1
fi

# 3. Ensure ~/.gstack global state directory exists
mkdir -p "$HOME/.gstack/projects"

# ─── Helper: link Claude skill subdirectories into a skills parent directory ──
link_claude_skill_dirs() {
  local gstack_dir="$1"
  local skills_dir="$2"
  local linked=()
  for skill_dir in "$gstack_dir"/*/; do
    if [ -f "$skill_dir/SKILL.md" ]; then
      skill_name="$(basename "$skill_dir")"
      # Skip node_modules
      [ "$skill_name" = "node_modules" ] && continue
      target="$skills_dir/$skill_name"
      # Create or update symlink; skip if a real file/directory exists
      if [ -L "$target" ] || [ ! -e "$target" ]; then
        ln -snf "gstack/$skill_name" "$target"
        linked+=("$skill_name")
      fi
    fi
  done
  if [ ${#linked[@]} -gt 0 ]; then
    echo "  linked skills: ${linked[*]}"
  fi
}

# ─── Helper: link generated Codex skills into a skills parent directory ──
# Installs from .agents/skills/gstack-* (the generated Codex-format skills)
# instead of source dirs (which have Claude paths).
link_codex_skill_dirs() {
  local gstack_dir="$1"
  local skills_dir="$2"
  local agents_dir="$gstack_dir/.agents/skills"
  local linked=()

  if [ ! -d "$agents_dir" ]; then
    echo "  warning: no .agents/skills/ directory found — run 'bun run build' first" >&2
    return 1
  fi

  for skill_dir in "$agents_dir"/gstack*/; do
    if [ -f "$skill_dir/SKILL.md" ]; then
      skill_name="$(basename "$skill_dir")"
      target="$skills_dir/$skill_name"
      # Create or update symlink
      if [ -L "$target" ] || [ ! -e "$target" ]; then
        ln -snf "$skill_dir" "$target"
        linked+=("$skill_name")
      fi
    fi
  done
  if [ ${#linked[@]} -gt 0 ]; then
    echo "  linked skills: ${linked[*]}"
  fi
}

# ─── Helper: create .agents/skills/gstack/ sidecar symlinks ──────────
# Codex/Gemini/Cursor read skills from .agents/skills/. We link runtime
# assets (bin/, browse/dist/, review/, qa/, etc.) so skill templates can
# resolve paths like $SKILL_ROOT/review/design-checklist.md.
create_agents_sidecar() {
  local repo_root="$1"
  local agents_gstack="$repo_root/.agents/skills/gstack"
  mkdir -p "$agents_gstack"

  # Sidecar directories that skills reference at runtime
  for asset in bin browse review qa; do
    local src="$GSTACK_DIR/$asset"
    local dst="$agents_gstack/$asset"
    if [ -d "$src" ] || [ -f "$src" ]; then
      if [ -L "$dst" ] || [ ! -e "$dst" ]; then
        ln -snf "$src" "$dst"
      fi
    fi
  done
}

# 4. Install for Claude (default)
SKILLS_BASENAME="$(basename "$SKILLS_DIR")"
if [ "$INSTALL_CLAUDE" -eq 1 ]; then
  if [ "$SKILLS_BASENAME" = "skills" ]; then
    link_claude_skill_dirs "$GSTACK_DIR" "$SKILLS_DIR"
    echo "gstack ready (claude)."
    echo "  browse: $BROWSE_BIN"
  else
    echo "gstack ready (claude)."
    echo "  browse: $BROWSE_BIN"
    echo "  (skipped skill symlinks — not inside .claude/skills/)"
  fi
fi

# 5. Install for Codex
if [ "$INSTALL_CODEX" -eq 1 ]; then
  CODEX_SKILLS="$HOME/.codex/skills"
  CODEX_GSTACK="$CODEX_SKILLS/gstack"
  mkdir -p "$CODEX_SKILLS"

  # Symlink gstack source for runtime assets (bin/, browse/dist/)
  if [ -L "$CODEX_GSTACK" ] || [ ! -e "$CODEX_GSTACK" ]; then
    ln -snf "$GSTACK_DIR" "$CODEX_GSTACK"
  fi
  # Install generated Codex-format skills (not Claude source dirs)
  link_codex_skill_dirs "$GSTACK_DIR" "$CODEX_SKILLS"

  echo "gstack ready (codex)."
  echo "  browse: $BROWSE_BIN"
  echo "  codex skills: $CODEX_SKILLS"
fi

# 6. Create .agents/ sidecar symlinks (useful for Codex/Gemini/Cursor workspace-local)
if [ "$INSTALL_CODEX" -eq 1 ]; then
  # Detect repo root: if we're inside a skills directory, go up two levels
  if [ "$SKILLS_BASENAME" = "skills" ]; then
    REPO_ROOT="$(dirname "$SKILLS_DIR")"
  else
    REPO_ROOT="$GSTACK_DIR"
  fi
  create_agents_sidecar "$REPO_ROOT"
fi

# 7. First-time welcome + legacy cleanup
if [ ! -d "$HOME/.gstack" ]; then
  mkdir -p "$HOME/.gstack"
  echo "  Welcome! Run /gstack-upgrade anytime to stay current."
fi
rm -f /tmp/gstack-latest-version