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

# Control script for deterministic Planetiler disk usage.
# Modes:
#   resume      Keep sources + reuse DB, clean only work temp, then start build.
#   fresh       Keep sources, delete work+reuse+output, then start build.
#   fresh-all   Delete output+sources+work+reuse, then start build.
#   clean-work  Delete only work temp.
#   clean-all   Delete output+sources+work+reuse (no start).
#   status      Show disk usage and reuse readiness.

MODE="${1:-status}"
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "${SCRIPT_DIR}/.." && pwd)"

OUTPUT_DIR="${REPO_ROOT}/build/output"
SOURCES_DIR="${REPO_ROOT}/build/sources"
WORK_DIR="${REPO_ROOT}/build/tmp/work"
REUSE_DIR="${REPO_ROOT}/build/tmp/reuse"
FEATURE_DB_DIR="${REUSE_DIR}/feature.db"
STRINGS_FILE="${FEATURE_DB_DIR}/feature.db.strings"
MANIFEST_FILE="${FEATURE_DB_DIR}/feature.db.manifest"

ensure_dirs() {
  mkdir -p "${OUTPUT_DIR}" "${SOURCES_DIR}" "${WORK_DIR}" "${REUSE_DIR}"
}

clear_dir() {
  local dir="$1"
  mkdir -p "${dir}"
  rm -rf "${dir}"/*
}

stop_build_container() {
  (cd "${REPO_ROOT}" && docker compose -f docker-compose.build.yml down)
}

start_build_container() {
  (cd "${REPO_ROOT}" && docker compose -f docker-compose.build.yml up -d)
}

reuse_ready() {
  [[ -d "${FEATURE_DB_DIR}" && -f "${STRINGS_FILE}" && -f "${MANIFEST_FILE}" ]]
}

print_status() {
  echo "== Disk Status =="
  (cd "${REPO_ROOT}" && df -h .)
  echo "---"
  du -sh "${REPO_ROOT}/build" "${OUTPUT_DIR}" "${SOURCES_DIR}" "${WORK_DIR}" "${REUSE_DIR}" 2>/dev/null || true
  echo "---"
  if reuse_ready; then
    echo "Reuse DB: READY (${FEATURE_DB_DIR} + strings + manifest)"
  else
    echo "Reuse DB: NOT READY"
    echo "Missing at least one of:"
    echo "  ${FEATURE_DB_DIR}"
    echo "  ${STRINGS_FILE}"
    echo "  ${MANIFEST_FILE}"
  fi
}

case "${MODE}" in
  resume)
    stop_build_container
    ensure_dirs
    clear_dir "${WORK_DIR}"
    print_status
    start_build_container
    ;;
  fresh)
    stop_build_container
    ensure_dirs
    clear_dir "${WORK_DIR}"
    clear_dir "${REUSE_DIR}"
    clear_dir "${OUTPUT_DIR}"
    print_status
    start_build_container
    ;;
  fresh-all)
    stop_build_container
    ensure_dirs
    clear_dir "${WORK_DIR}"
    clear_dir "${REUSE_DIR}"
    clear_dir "${OUTPUT_DIR}"
    clear_dir "${SOURCES_DIR}"
    print_status
    start_build_container
    ;;
  clean-work)
    stop_build_container
    ensure_dirs
    clear_dir "${WORK_DIR}"
    print_status
    ;;
  clean-all)
    stop_build_container
    ensure_dirs
    clear_dir "${WORK_DIR}"
    clear_dir "${REUSE_DIR}"
    clear_dir "${OUTPUT_DIR}"
    clear_dir "${SOURCES_DIR}"
    print_status
    ;;
  status)
    ensure_dirs
    print_status
    ;;
  *)
    echo "Unknown mode: ${MODE}"
    echo "Usage: $0 [resume|fresh|fresh-all|clean-work|clean-all|status]"
    exit 1
    ;;
esac

echo "Done: ${MODE}"