using System.Text.Json.Nodes;

namespace NpgsqlRest;

/// <summary>

/// One rule in a cache profile's <see cref="CacheProfile.When"/> list. Each rule combines:

///

/// - A <see cref="Parameter"/> name (a routine parameter to inspect at request time).

/// - A <see cref="Value"/> condition (scalar = exact match; array = OR over entries; JSON null matches .NET null/DBNull).

/// - An action: <see cref="Skip"/> = true → bypass the cache (no read, no write); otherwise <see cref="ThenExpiration"/>

/// is used to override the entry's TTL for this write.

///

/// In JSON config the action is expressed as a single <c>"Then"</c> field: the literal string <c>"skip"</c> sets

/// <see cref="Skip"/> = true; a PostgreSQL interval (e.g. <c>"30 seconds"</c>) sets <see cref="ThenExpiration"/>.

///

/// Multiple rules are evaluated in declaration order; first match wins. No match → fall through to the profile's

/// (or annotation's) default <see cref="CacheProfile.Expiration"/>.

///

/// Validation at startup: a rule whose <see cref="Parameter"/> name is not a real routine parameter, or which is

/// not part of the resolved cache-key parameter list, is dropped with a Warning. A rule with missing/invalid

/// <c>"Then"</c> JSON value is also dropped with a Warning.

/// </summary>

public class CacheWhenRule

{

/// <summary>

/// Routine parameter name to inspect (matches against either ActualName or ConvertedName).

/// </summary>

public string Parameter { get; set; } = "";

/// <summary>

/// Match condition. Scalar (single match) or JSON array (OR over entries). JSON null matches .NET null / DBNull.

/// String/number match is case-insensitive ordinal on the stringified parameter value.

/// </summary>

public JsonNode? Value { get; set; }

/// <summary>

/// When this rule matches at request time:

/// - <c>true</c> → bypass the cache entirely for this request (no read, no write).

/// - <c>false</c> → use <see cref="ThenExpiration"/> as the entry's TTL when writing.

///

/// Set during config parsing based on the JSON <c>"Then"</c> value: <c>"skip"</c> → true; PG interval → false.

/// </summary>

public bool Skip { get; set; }

/// <summary>

/// Override TTL applied to writes that match this rule. Only used when <see cref="Skip"/> is false.

/// Null = entry never expires (matches the existing CacheExpiresIn=null behavior).

/// </summary>

public TimeSpan? ThenExpiration { get; set; }

}