using System.Data;
using Database.Common;
using Insight.Database;

namespace Database.RolesPermissionSystem
{
    public class Setup
    {
        IDbConnection _db;
        string _schema;

        public Setup(IDbConnection db)
        {
            _db = db;
        }

        /// <summary>
        /// Creates the system tables in the specified schema within a transaction.
        /// </summary>
        /// <param name="schema">The schema name where the tables will be created.</param>
        public void CreateSystem(string schema)
        {
            _schema = schema;

            if (!Validations.IsValidSchemaName(_schema))
                throw new ArgumentException("Invalid schema name", _schema);

            using (var transaction = _db.BeginTransaction())
            {
                try
                {
                    CreateRolesTable();
                    CreatePermissionsTable();
                    CreatePermissionTypesTable();
                    CreateRolePermissionsTable();

                    transaction.Commit();
                }
                catch (Exception ex)
                {
                    transaction.Rollback();
                    throw new InvalidOperationException("Failed to create system tables.", ex);
                }
            }
        }


        private void ExecuteSql(string sql)
        {
            _db.ExecuteSql(sql);
        }

        private void CreatePermissionTypesTable()
        {
            var sql = $@"
            CREATE TABLE IF NOT EXISTS {_schema}.permission_types (
                id SERIAL PRIMARY KEY,
                name VARCHAR(100) NOT NULL UNIQUE
            )";
            ExecuteSql(sql);
        }

        private void CreatePermissionsTable()
        {
            var sql = $@"
            CREATE TABLE IF NOT EXISTS {_schema}.permissions (
                id SERIAL PRIMARY KEY,
                name VARCHAR(100) NOT NULL UNIQUE,
                type_id INTEGER NOT NULL,
                FOREIGN KEY (type_id) REFERENCES {_schema}.permission_types(id)
            )";
            ExecuteSql(sql);
        }

        private void CreateRolesTable()
        {
            var sql = $@"
            CREATE TABLE IF NOT EXISTS {_schema}.roles (
                id SERIAL PRIMARY KEY,
                name VARCHAR(100) NOT NULL UNIQUE
            )";
            ExecuteSql(sql);
        }

        private void CreateRolePermissionsTable()
        {
            var sql = $@"
            CREATE TABLE IF NOT EXISTS {_schema}.role_permissions (
                role_id INTEGER NOT NULL,
                permission_id INTEGER NOT NULL,
                PRIMARY KEY (role_id, permission_id),
                FOREIGN KEY (role_id) REFERENCES {_schema}.roles(id),
                FOREIGN KEY (permission_id) REFERENCES {_schema}.permissions(id)
            )";
            ExecuteSql(sql);
        }
    }
}