#!/usr/bin/env bash

set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
ENV_FILE="${ENV_FILE:-$ROOT_DIR/.env}"
DUMP_FILE=""
DRY_RUN=0
FORCE=0

if [[ -f "$ENV_FILE" ]]; then
    set -a
    # shellcheck disable=SC1090
    source "$ENV_FILE"
    set +a
fi

usage() {
    cat <<EOF
Usage: $(basename "$0") --from FILE [--dry-run] [--force]

Restores a full database dump (produced by db-export.sh) into the
ac-database Docker container. The container must be running.

Options:
  --from FILE   Dump file to restore (.sql or .sql.gz) (required)
  --dry-run     Show what would happen without executing
  --force       Skip the confirmation prompt
  -h, --help    Show this help

Examples:
  $(basename "$0") --from backups/2025-01-01_12-00-00.sql.gz
  $(basename "$0") --from /mnt/backup/dump.sql.gz --force
EOF
}

log() { printf '[db-import] %s\n' "$*"; }
die() { printf 'ERROR: %s\n' "$*" >&2; exit 1; }

require_ready_db() {
    if ! docker compose ps --status running --services 2>/dev/null | grep -qx 'ac-database'; then
        die "ac-database is not running. Start it with: docker compose up -d ac-database"
    fi

    log "waiting for MySQL to be ready..."
    local attempts=0
    until docker compose exec -T ac-database bash -lc \
            "mysql -h 127.0.0.1 -uroot -p\"\$MYSQL_ROOT_PASSWORD\" -e 'SELECT 1;'" \
            >/dev/null 2>&1; do
        attempts=$((attempts + 1))
        if [[ $attempts -ge 30 ]]; then
            die "MySQL did not become ready in time. Check: docker logs ac-database"
        fi
        sleep 2
    done
    log "MySQL is ready"
}

mysql_exec() {
    docker compose exec -T ac-database bash -lc \
        "mysql -h 127.0.0.1 -uroot -p\"\$MYSQL_ROOT_PASSWORD\""
}

# ── argument parsing ──────────────────────────────────────────────────────────

while (($#)); do
    case "$1" in
        --from)    DUMP_FILE="$2"; shift ;;
        --dry-run) DRY_RUN=1 ;;
        --force)   FORCE=1 ;;
        -h|--help) usage; exit 0 ;;
        *) printf 'Unknown option: %s\n\n' "$1" >&2; usage >&2; exit 1 ;;
    esac
    shift
done

# ── validation ────────────────────────────────────────────────────────────────

[[ -z "$DUMP_FILE" ]] && { usage >&2; die "--from FILE is required"; }
[[ -f "$DUMP_FILE" ]] || die "file not found: $DUMP_FILE"

cd "$ROOT_DIR"

# ── preview ───────────────────────────────────────────────────────────────────

file_size="$(du -sh "$DUMP_FILE" | cut -f1)"

printf '\nMigration plan:\n'
printf '  Source : %s (%s)\n' "$DUMP_FILE" "$file_size"
printf '  Target : ac-database container\n\n'

if [[ "$DRY_RUN" -eq 1 ]]; then
    log "dry-run mode — nothing imported"
    exit 0
fi

if [[ "$FORCE" -eq 0 ]]; then
    printf 'WARNING: this will DROP and recreate all databases in the dump.\n'
    read -r -p "Continue? [y/N] " confirm
    [[ "$confirm" =~ ^[Yy]$ ]] || { log "aborted"; exit 0; }
fi

# ── import ────────────────────────────────────────────────────────────────────

require_ready_db

log "restoring $DUMP_FILE into ac-database..."
log "this may take several minutes..."

if [[ "$DUMP_FILE" == *.gz ]]; then
    zcat "$DUMP_FILE" | mysql_exec
else
    mysql_exec < "$DUMP_FILE"
fi

log "import complete"
log ""
log "next steps:"
log "  1. Update realmlist:  bash sync-realmlist.sh"
log "  2. Start the server:  bash scripts/prod-deploy.sh --no-build"