#!/bin/sh
set -eu

PSQL="psql --no-psqlrc --set=ON_ERROR_STOP=1"

echo "Проверка таблицы миграций"

$PSQL <<'SQL'
CREATE TABLE IF NOT EXISTS public.schema_migrations (
    version text PRIMARY KEY,
    checksum text NOT NULL,
    applied_at timestamptz NOT NULL DEFAULT now()
);

REVOKE ALL ON public.schema_migrations FROM PUBLIC;
SQL

find /migrations \
    -maxdepth 1 \
    -type f \
    -name '[0-9][0-9][0-9]_*.sql' |
sort |
while IFS= read -r file; do
    version="$(basename "$file")"
    checksum="$(sha256sum "$file" | cut -d ' ' -f 1)"

    saved_checksum="$(
        $PSQL \
            --tuples-only \
            --no-align \
            --set=migration_version="$version" <<'SQL'
SELECT checksum
FROM public.schema_migrations
WHERE version = :'migration_version';
SQL
    )"

    if [ -n "$saved_checksum" ]; then
        if [ "$saved_checksum" != "$checksum" ]; then
            echo "Ошибка: применённая миграция $version была изменена"
            exit 1
        fi

        echo "Пропуск $version"
        continue
    fi

    echo "Применение $version"

    {
        echo "BEGIN;"
        cat "$file"
        echo ""
        echo "INSERT INTO public.schema_migrations(version, checksum)"
        echo "VALUES (:'migration_version', :'migration_checksum');"
        echo "COMMIT;"
    } |
        $PSQL \
            --set=migration_version="$version" \
            --set=migration_checksum="$checksum"

    echo "Миграция $version применена"
done

echo "Все миграции применены"