#!/usr/bin/env bash
# Run StemeDB load tests with a fresh server instance.
#
# Usage:
#   ./scripts/run-load-test.sh                    # Quick test (5 min sustained)
#   LOAD_TEST_DURATION=1h ./scripts/run-load-test.sh  # Full 1-hour test
#   ./scripts/run-load-test.sh --scenario baseline    # Run specific scenario
#
# Environment variables:
#   STEMEDB_PORT         - API port (default: 18180)
#   STEMEDB_DATA_DIR     - Data directory (default: /tmp/stemedb-loadtest)
#   LOAD_TEST_DURATION   - Sustained test duration (default: 5m)
#   LOAD_TEST_TARGET_RPS - Target writes/sec (default: 1000)
#   LOAD_TEST_READERS    - Concurrent readers (default: 100)
#
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"

# Configuration
API_PORT="${STEMEDB_PORT:-18180}"
API_URL="http://127.0.0.1:${API_PORT}"
DATA_DIR="${STEMEDB_DATA_DIR:-/tmp/stemedb-loadtest}"
DURATION="${LOAD_TEST_DURATION:-5m}"
TARGET_RPS="${LOAD_TEST_TARGET_RPS:-1000}"
READERS="${LOAD_TEST_READERS:-100}"

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

log_info() { echo -e "${GREEN}[INFO]${NC} $*"; }
log_warn() { echo -e "${YELLOW}[WARN]${NC} $*"; }
log_error() { echo -e "${RED}[ERROR]${NC} $*"; }

cleanup() {
    if [[ -n "${API_PID:-}" ]]; then
        log_info "Stopping StemeDB API (PID: $API_PID)..."
        kill "$API_PID" 2>/dev/null || true
        wait "$API_PID" 2>/dev/null || true
    fi
}
trap cleanup EXIT

# Parse arguments to pass through to load-test
LOAD_TEST_ARGS=("$@")

cd "$REPO_ROOT"

# Clean state for reproducible results
log_info "Cleaning data directory: $DATA_DIR"
rm -rf "$DATA_DIR" && mkdir -p "$DATA_DIR"

# Build the load tester
log_info "Building load tester..."
cd cmd/load-test
go build -o "$REPO_ROOT/target/load-test" .
cd "$REPO_ROOT"

# Build and start the server with meter disabled
log_info "Building and starting StemeDB API (release mode)..."
log_info "  Data dir: $DATA_DIR"
log_info "  API URL:  $API_URL"

STEMEDB_METER_ENABLED=false \
STEMEDB_WAL_DIR="$DATA_DIR/wal" \
STEMEDB_DB_DIR="$DATA_DIR/db" \
STEMEDB_BIND_ADDR="127.0.0.1:$API_PORT" \
cargo run --release --bin stemedb-api 2>&1 | sed 's/^/  [server] /' &
API_PID=$!

# Wait for server to be ready
log_info "Waiting for API to be ready..."
for i in {1..60}; do
    if curl -sf "$API_URL/v1/health" >/dev/null 2>&1; then
        log_info "API is ready (attempt $i)"
        break
    fi
    if ! kill -0 "$API_PID" 2>/dev/null; then
        log_error "Server process died unexpectedly"
        exit 1
    fi
    sleep 1
done

# Verify server is actually running
if ! curl -sf "$API_URL/v1/health" >/dev/null 2>&1; then
    log_error "API failed to start within 60 seconds"
    exit 1
fi

# Show server health
HEALTH=$(curl -sf "$API_URL/v1/health")
log_info "Server health: $HEALTH"

# Run load tests
log_info "Starting load tests..."
log_info "  Duration:   $DURATION"
log_info "  Target RPS: $TARGET_RPS"
log_info "  Readers:    $READERS"
echo

"$REPO_ROOT/target/load-test" \
    --api-url "$API_URL" \
    --keys-file "$REPO_ROOT/demo/keys/agents.json" \
    --output "$REPO_ROOT/uat/production-readiness/results" \
    --duration "$DURATION" \
    --target-rps "$TARGET_RPS" \
    --readers "$READERS" \
    "${LOAD_TEST_ARGS[@]}"

EXIT_CODE=$?

echo
log_info "Load test complete."
log_info "Results saved to: uat/production-readiness/results/"

# Show final assertion count
FINAL_HEALTH=$(curl -sf "$API_URL/v1/health" 2>/dev/null || echo '{"assertions_count": "unknown"}')
log_info "Final server state: $FINAL_HEALTH"

exit $EXIT_CODE