using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;

namespace ErsatzTV.Infrastructure.Sqlite.Data;

/// <summary>
///     Classifies SQLite provider exceptions wrapped by EF Core. Wired to
///     <see cref="ErsatzTV.Infrastructure.Data.TvContext.IsUniqueConstraintViolation" /> at startup.
/// </summary>
public static class SqliteErrorClassifier
{
    // SQLITE_CONSTRAINT (primary result code 19), narrowed to the two extended codes that mean a
    // duplicate key: SQLITE_CONSTRAINT_PRIMARYKEY (1555) and SQLITE_CONSTRAINT_UNIQUE (2067). Other
    // constraint failures (FK 787, NOT NULL 1299, CHECK 275) are deliberately NOT treated as duplicates.
    private const int SqliteConstraint = 19;
    private const int SqliteConstraintPrimaryKey = 1555;
    private const int SqliteConstraintUnique = 2067;

    public static bool IsUniqueConstraintViolation(DbUpdateException ex) =>
        ex.InnerException is SqliteException { SqliteErrorCode: SqliteConstraint } inner
        && inner.SqliteExtendedErrorCode is SqliteConstraintPrimaryKey or SqliteConstraintUnique;
}