// -----------------------------------------------------------------------------
// SymbolTableDiff.cs
// Sprint: SPRINT_20260106_001_003_BINDEX_symbol_table_diff
// Tasks: SYM-001, SYM-002, SYM-003, SYM-004, SYM-005
// Description: Symbol table diff model for comparing exports/imports between binaries
// -----------------------------------------------------------------------------

using System.Text.Json.Serialization;

namespace StellaOps.BinaryIndex.Builders.SymbolDiff;

/// <summary>
/// Complete symbol table diff between two binaries.
/// </summary>
public sealed record SymbolTableDiff
{
    /// <summary>Content-addressed diff ID (sha256 of canonical JSON).</summary>
    [JsonPropertyName("diff_id")]
    public required string DiffId { get; init; }

    /// <summary>Base binary identity.</summary>
    [JsonPropertyName("base")]
    public required BinaryRef Base { get; init; }

    /// <summary>Target binary identity.</summary>
    [JsonPropertyName("target")]
    public required BinaryRef Target { get; init; }

    /// <summary>Exported symbol changes.</summary>
    [JsonPropertyName("exports")]
    public required SymbolChangeSummary Exports { get; init; }

    /// <summary>Imported symbol changes.</summary>
    [JsonPropertyName("imports")]
    public required SymbolChangeSummary Imports { get; init; }

    /// <summary>Version map changes.</summary>
    [JsonPropertyName("versions")]
    public required VersionMapDiff Versions { get; init; }

    /// <summary>GOT/PLT changes (dynamic linking).</summary>
    [JsonPropertyName("dynamic")]
    public DynamicLinkingDiff? Dynamic { get; init; }

    /// <summary>Overall ABI compatibility assessment.</summary>
    [JsonPropertyName("abi_compatibility")]
    public required AbiCompatibility AbiCompatibility { get; init; }

    /// <summary>When this diff was computed (UTC).</summary>
    [JsonPropertyName("computed_at")]
    public required DateTimeOffset ComputedAt { get; init; }

    /// <summary>Schema version for forward compatibility.</summary>
    [JsonPropertyName("schema_version")]
    public string SchemaVersion { get; init; } = "1.0";
}

/// <summary>Reference to a binary.</summary>
public sealed record BinaryRef
{
    [JsonPropertyName("path")]
    public required string Path { get; init; }

    [JsonPropertyName("sha256")]
    public required string Sha256 { get; init; }

    [JsonPropertyName("build_id")]
    public string? BuildId { get; init; }

    [JsonPropertyName("architecture")]
    public required string Architecture { get; init; }

    [JsonPropertyName("format")]
    public required BinaryFormat Format { get; init; }

    [JsonPropertyName("file_size")]
    public long FileSize { get; init; }
}

/// <summary>Binary format.</summary>
[JsonConverter(typeof(JsonStringEnumConverter))]
public enum BinaryFormat
{
    Elf,
    Pe,
    MachO,
    Unknown
}

/// <summary>Summary of symbol changes.</summary>
public sealed record SymbolChangeSummary
{
    [JsonPropertyName("added")]
    public required IReadOnlyList<SymbolChange> Added { get; init; }

    [JsonPropertyName("removed")]
    public required IReadOnlyList<SymbolChange> Removed { get; init; }

    [JsonPropertyName("modified")]
    public required IReadOnlyList<SymbolModification> Modified { get; init; }

    [JsonPropertyName("renamed")]
    public required IReadOnlyList<SymbolRename> Renamed { get; init; }

    /// <summary>Count summaries.</summary>
    [JsonPropertyName("counts")]
    public required SymbolChangeCounts Counts { get; init; }
}

/// <summary>Count summary for symbol changes.</summary>
public sealed record SymbolChangeCounts
{
    [JsonPropertyName("added")]
    public int Added { get; init; }

    [JsonPropertyName("removed")]
    public int Removed { get; init; }

    [JsonPropertyName("modified")]
    public int Modified { get; init; }

    [JsonPropertyName("renamed")]
    public int Renamed { get; init; }

    [JsonPropertyName("unchanged")]
    public int Unchanged { get; init; }

    [JsonPropertyName("total_base")]
    public int TotalBase { get; init; }

    [JsonPropertyName("total_target")]
    public int TotalTarget { get; init; }
}

/// <summary>A symbol that was added or removed.</summary>
public sealed record SymbolChange
{
    [JsonPropertyName("name")]
    public required string Name { get; init; }

    [JsonPropertyName("demangled_name")]
    public string? DemangledName { get; init; }

    [JsonPropertyName("type")]
    public required SymbolType Type { get; init; }

    [JsonPropertyName("binding")]
    public required SymbolBinding Binding { get; init; }

    [JsonPropertyName("visibility")]
    public required SymbolVisibility Visibility { get; init; }

    [JsonPropertyName("section")]
    public string? Section { get; init; }

    [JsonPropertyName("address")]
    public ulong Address { get; init; }

    [JsonPropertyName("size")]
    public ulong Size { get; init; }

    [JsonPropertyName("version")]
    public string? Version { get; init; }

    [JsonPropertyName("fingerprint")]
    public string? Fingerprint { get; init; }
}

/// <summary>A symbol that was modified (same name, different attributes).</summary>
public sealed record SymbolModification
{
    [JsonPropertyName("name")]
    public required string Name { get; init; }

    [JsonPropertyName("demangled_name")]
    public string? DemangledName { get; init; }

    [JsonPropertyName("base")]
    public required SymbolAttributes Base { get; init; }

    [JsonPropertyName("target")]
    public required SymbolAttributes Target { get; init; }

    [JsonPropertyName("changes")]
    public required IReadOnlyList<AttributeChange> Changes { get; init; }

    [JsonPropertyName("is_abi_breaking")]
    public bool IsAbiBreaking { get; init; }
}

/// <summary>Symbol attributes for comparison.</summary>
public sealed record SymbolAttributes
{
    [JsonPropertyName("type")]
    public required SymbolType Type { get; init; }

    [JsonPropertyName("binding")]
    public required SymbolBinding Binding { get; init; }

    [JsonPropertyName("visibility")]
    public required SymbolVisibility Visibility { get; init; }

    [JsonPropertyName("section")]
    public string? Section { get; init; }

    [JsonPropertyName("address")]
    public ulong Address { get; init; }

    [JsonPropertyName("size")]
    public ulong Size { get; init; }

    [JsonPropertyName("version")]
    public string? Version { get; init; }

    [JsonPropertyName("fingerprint")]
    public string? Fingerprint { get; init; }
}

/// <summary>A specific attribute change.</summary>
public sealed record AttributeChange
{
    [JsonPropertyName("attribute")]
    public required string Attribute { get; init; }

    [JsonPropertyName("base_value")]
    public string? BaseValue { get; init; }

    [JsonPropertyName("target_value")]
    public string? TargetValue { get; init; }

    [JsonPropertyName("severity")]
    public required ChangeSeverity Severity { get; init; }
}

/// <summary>A symbol that was renamed (detected via fingerprint matching).</summary>
public sealed record SymbolRename
{
    [JsonPropertyName("base_name")]
    public required string BaseName { get; init; }

    [JsonPropertyName("target_name")]
    public required string TargetName { get; init; }

    [JsonPropertyName("base_demangled")]
    public string? BaseDemangled { get; init; }

    [JsonPropertyName("target_demangled")]
    public string? TargetDemangled { get; init; }

    [JsonPropertyName("fingerprint")]
    public required string Fingerprint { get; init; }

    [JsonPropertyName("similarity")]
    public double Similarity { get; init; }

    [JsonPropertyName("confidence")]
    public required RenameConfidence Confidence { get; init; }
}

/// <summary>Symbol type classification.</summary>
[JsonConverter(typeof(JsonStringEnumConverter))]
public enum SymbolType
{
    NoType,
    Object,
    Function,
    Section,
    File,
    Common,
    Tls,
    Unknown
}

/// <summary>Symbol binding.</summary>
[JsonConverter(typeof(JsonStringEnumConverter))]
public enum SymbolBinding
{
    Local,
    Global,
    Weak,
    Unknown
}

/// <summary>Symbol visibility.</summary>
[JsonConverter(typeof(JsonStringEnumConverter))]
public enum SymbolVisibility
{
    Default,
    Internal,
    Hidden,
    Protected,
    Unknown
}

/// <summary>Severity of a change.</summary>
[JsonConverter(typeof(JsonStringEnumConverter))]
public enum ChangeSeverity
{
    Info,
    Low,
    Medium,
    High,
    Critical
}

/// <summary>Confidence level for rename detection.</summary>
[JsonConverter(typeof(JsonStringEnumConverter))]
public enum RenameConfidence
{
    VeryHigh,
    High,
    Medium,
    Low,
    VeryLow
}