#!/usr/bin/env bash
# resume_session.sh — resume a stopped session
set -euo pipefail

source "$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)/lib.sh"

usage() {
  cat <<EOF
Usage: $0 --workspace <path> --agent <claude|agy|hermes|cline> --session <name> [--dry-run]

Options:
  --dry-run   Simulates resume flow (resolves binary, environment, isolation) without writing
              any updates to YAML or DB. Safe to execute inside active write transactions.
EOF
}

WORKSPACE=""
AGENT=""
SESSION_NAME=""

DRY_RUN=0

while [ $# -gt 0 ]; do
  case "$1" in
    --workspace) WORKSPACE="$2"; shift 2 ;;
    --agent)     AGENT="$2";     shift 2 ;;
    --session)   SESSION_NAME="$2"; shift 2 ;;
    --dry-run)   DRY_RUN=1; shift ;;
    -h|--help)   usage; exit 0 ;;
    *) echo "ERROR: unknown arg: $1" >&2; exit 2 ;;
  esac
done

[ -n "$WORKSPACE" ] || { echo "ERROR: --workspace required" >&2; exit 2; }
[ -n "$AGENT" ]    || { echo "ERROR: --agent required" >&2; exit 2; }
[ -n "$SESSION_NAME" ] || { echo "ERROR: --session required" >&2; exit 2; }

# 1. Resolve the session id
UUID=$(bash "$(dirname "${BASH_SOURCE[0]}")/resolve_session_id.sh" \
  --workspace "$WORKSPACE" --agent "$AGENT" --session "$SESSION_NAME")

if [ -z "$UUID" ]; then
  echo "ERROR: No saved session for $WORKSPACE ($AGENT). Use multi-agent-mux-create first." >&2
  exit 1
fi

HERDR_SERVER_NAME="$(resolve_herdr_workspace "$SESSION_NAME")"
export HERDR_SERVER_NAME

# 2. If herdr is alive, print warning or attach.
if herdr has-session -t "$SESSION_NAME" 2>/dev/null; then
  if [ "${DRY_RUN:-0}" = "1" ]; then
    echo "[dry-run] herdr '$SESSION_NAME' already running — nothing to validate"
    exit 0
  fi
  echo "herdr '$SESSION_NAME' already running."
  # Just update YAML to make sure it's set to running
  bash "$(dirname "${BASH_SOURCE[0]}")/update_yaml_resumed.sh" \
    --session "$SESSION_NAME" --uuid "$UUID" --agent "$AGENT"
  exit 0
fi

# 3. Resolve isolation settings for this session
ISO_ROOT=""
ISO_ENV=""
ISO_ARGS=""

ISO_DATA=$(env_python "$AGENT_SESSIONS_YAML" SESSION_NAME="$SESSION_NAME" <<'PYEOF'
import os, json, yaml, sqlite3
name = os.environ['SESSION_NAME']
yaml_path = os.environ['YAML_PATH']
db_path = os.path.splitext(yaml_path)[0] + '.db'
d = {}
try:
    if os.path.exists(db_path):
        conn = sqlite3.connect(db_path, timeout=60.0)
        row = conn.execute('SELECT data FROM sessions WHERE name=?', (name,)).fetchone()
        if row:
            s = json.loads(row[0])
            print(json.dumps(s.get('isolation') or {}))
            raise SystemExit(0)
    elif os.path.exists(yaml_path):
        with open(yaml_path) as f:
            d = yaml.safe_load(f) or {}
except Exception:
    pass
for s in d.get('herdr_sessions', []):
    if s.get('name') == name:
        print(json.dumps(s.get('isolation') or {}))
        raise SystemExit(0)
print("{}")
PYEOF
)

ISO_ROOT=$(printf '%s' "$ISO_DATA" | python3 -c 'import sys,json; print(json.load(sys.stdin).get("root",""))')
if [ -n "$ISO_ROOT" ]; then
  ISO_ENV="$(isolation_env_prefix "$AGENT" "$ISO_ROOT")"
  ISO_ARGS="$(isolation_cmd_args "$AGENT" "$ISO_ROOT")"
  echo "Re-applying isolation: root=$ISO_ROOT env=$ISO_ENV args=$ISO_ARGS"
fi

# Resolve absolute path of the agent command to prevent herdr PATH inheritance issues (especially on macOS)
RESOLVED_BIN="$AGENT"
if [ "$AGENT" = "cline" ]; then
  if command -v cline >/dev/null 2>&1; then
    RESOLVED_BIN="$(command -v cline)"
  fi
else
  if command -v "$AGENT" >/dev/null 2>&1; then
    RESOLVED_BIN="$(command -v "$AGENT")"
  fi
fi

# On macOS, clear quarantine attribute for the agent binary to prevent Gatekeeper hangs
if [ "$(uname)" = "Darwin" ] && [ -f "$RESOLVED_BIN" ]; then
  xattr -d com.apple.quarantine "$RESOLVED_BIN" 2>/dev/null || true
fi

# Determine CMD_FULL with isolation applied
case "$AGENT" in
  claude) CMD_FULL="${RESOLVED_BIN} --dangerously-skip-permissions -r $UUID" ;;
  agy)    CMD_FULL="${RESOLVED_BIN} --dangerously-skip-permissions --conversation $UUID" ;;
  hermes) CMD_FULL="${RESOLVED_BIN} --resume $UUID" ;;
  cline)  CMD_FULL="${RESOLVED_BIN} -i --id $UUID" ;;
  *)      echo "ERROR: unsupported agent: $AGENT" >&2; exit 2 ;;
esac

# Prepend env prefix and append command args (T4)
if [ -n "$ISO_ENV" ]; then
  CMD_FULL="$ISO_ENV $CMD_FULL"
fi
if [ -n "$ISO_ARGS" ]; then
  CMD_FULL="$CMD_FULL $ISO_ARGS"
fi

# Validate isolation root if it was configured
if [ -n "$ISO_ROOT" ] && [ ! -d "$ISO_ROOT" ]; then
  echo "ERROR: Isolation root directory does not exist: $ISO_ROOT" >&2
  exit 1
fi

# Validate binary exists and is executable
if [ -f "$RESOLVED_BIN" ] || [[ "$RESOLVED_BIN" == /* ]] || [[ "$RESOLVED_BIN" == ~/* ]]; then
  if [ ! -x "$RESOLVED_BIN" ]; then
    echo "ERROR: Agent binary is not executable: $RESOLVED_BIN" >&2
    exit 1
  fi
else
  if ! command -v "$RESOLVED_BIN" >/dev/null 2>&1; then
    echo "ERROR: Agent binary not found in PATH: $RESOLVED_BIN" >&2
    exit 1
  fi
fi

if [ "${DRY_RUN:-0}" = "1" ]; then
  echo "[dry-run] would spawn: $CMD_FULL"
  exit 0
fi

# 4. Spawn new agent session (delegates to herdr translation shim)
_herdr new-session -d -s "$SESSION_NAME" -c "$WORKSPACE" "$CMD_FULL"
if [ "$AGENT" = "claude" ]; then
  # auto-handle trust / bypass dialogs
  handle_startup_dialogs "$SESSION_NAME" 20
fi

# Wait for TUI readiness or let it settle
sleep 2

# 5. Update agent-sessions.yaml: status running, last_visible_status
bash "$(dirname "${BASH_SOURCE[0]}")/update_yaml_resumed.sh" \
  --session "$SESSION_NAME" --uuid "$UUID" --agent "$AGENT"

echo "Successfully resumed $SESSION_NAME ($AGENT)"