// <copyright file="ChatContracts.cs" company="StellaOps">
// Copyright (c) StellaOps. Licensed under the BUSL-1.1.
// </copyright>


using StellaOps.AdvisoryAI.Chat;
using System.Collections.Immutable;
using System.Text.Json.Serialization;

namespace StellaOps.AdvisoryAI.WebService.Contracts;

/// <summary>
/// Request to create a new conversation.
/// Sprint: SPRINT_20260107_006_003 Task CH-005
/// </summary>
public sealed record CreateConversationRequest
{
    /// <summary>
    /// Gets the tenant identifier.
    /// </summary>
    [JsonPropertyName("tenantId")]
    public required string TenantId { get; init; }

    /// <summary>
    /// Gets the optional initial context for the conversation.
    /// </summary>
    [JsonPropertyName("context")]
    public ConversationContextRequest? Context { get; init; }

    /// <summary>
    /// Gets optional metadata key-value pairs.
    /// </summary>
    [JsonPropertyName("metadata")]
    public IReadOnlyDictionary<string, string>? Metadata { get; init; }
}

/// <summary>
/// Request for conversation context initialization.
/// </summary>
public sealed record ConversationContextRequest
{
    /// <summary>
    /// Gets the current CVE ID being discussed.
    /// </summary>
    [JsonPropertyName("currentCveId")]
    public string? CurrentCveId { get; init; }

    /// <summary>
    /// Gets the current component PURL.
    /// </summary>
    [JsonPropertyName("currentComponent")]
    public string? CurrentComponent { get; init; }

    /// <summary>
    /// Gets the current image digest.
    /// </summary>
    [JsonPropertyName("currentImageDigest")]
    public string? CurrentImageDigest { get; init; }

    /// <summary>
    /// Gets the scan ID in context.
    /// </summary>
    [JsonPropertyName("scanId")]
    public string? ScanId { get; init; }

    /// <summary>
    /// Gets the SBOM ID in context.
    /// </summary>
    [JsonPropertyName("sbomId")]
    public string? SbomId { get; init; }
}

/// <summary>
/// Request to add a turn to an existing conversation.
/// </summary>
public sealed record AddTurnRequest
{
    /// <summary>
    /// Gets the user message content.
    /// </summary>
    [JsonPropertyName("content")]
    public required string Content { get; init; }

    /// <summary>
    /// Gets optional metadata for this turn.
    /// </summary>
    [JsonPropertyName("metadata")]
    public IReadOnlyDictionary<string, string>? Metadata { get; init; }

    /// <summary>
    /// Gets whether to stream the response as Server-Sent Events.
    /// </summary>
    [JsonPropertyName("stream")]
    public bool Stream { get; init; } = false;
}

/// <summary>
/// Response for a created conversation.
/// </summary>
public sealed record ConversationResponse
{
    /// <summary>
    /// Gets the conversation ID.
    /// </summary>
    [JsonPropertyName("conversationId")]
    public required string ConversationId { get; init; }

    /// <summary>
    /// Gets the tenant ID.
    /// </summary>
    [JsonPropertyName("tenantId")]
    public required string TenantId { get; init; }

    /// <summary>
    /// Gets the user ID.
    /// </summary>
    [JsonPropertyName("userId")]
    public required string UserId { get; init; }

    /// <summary>
    /// Gets the creation timestamp.
    /// </summary>
    [JsonPropertyName("createdAt")]
    public required DateTimeOffset CreatedAt { get; init; }

    /// <summary>
    /// Gets the last update timestamp.
    /// </summary>
    [JsonPropertyName("updatedAt")]
    public required DateTimeOffset UpdatedAt { get; init; }

    /// <summary>
    /// Gets the conversation turns.
    /// </summary>
    [JsonPropertyName("turns")]
    public required IReadOnlyList<ConversationTurnResponse> Turns { get; init; }

    /// <summary>
    /// Creates a response from a conversation.
    /// </summary>
    public static ConversationResponse FromConversation(Conversation conversation) => new()
    {
        ConversationId = conversation.ConversationId,
        TenantId = conversation.TenantId,
        UserId = conversation.UserId,
        CreatedAt = conversation.CreatedAt,
        UpdatedAt = conversation.UpdatedAt,
        Turns = conversation.Turns.Select(ConversationTurnResponse.FromTurn).ToList()
    };
}

/// <summary>
/// Response for a conversation turn.
/// </summary>
public sealed record ConversationTurnResponse
{
    /// <summary>
    /// Gets the turn ID.
    /// </summary>
    [JsonPropertyName("turnId")]
    public required string TurnId { get; init; }

    /// <summary>
    /// Gets the role (user, assistant, system).
    /// </summary>
    [JsonPropertyName("role")]
    public required string Role { get; init; }

    /// <summary>
    /// Gets the message content.
    /// </summary>
    [JsonPropertyName("content")]
    public required string Content { get; init; }

    /// <summary>
    /// Gets the timestamp.
    /// </summary>
    [JsonPropertyName("timestamp")]
    public required DateTimeOffset Timestamp { get; init; }

    /// <summary>
    /// Gets the evidence links in this turn.
    /// </summary>
    [JsonPropertyName("evidenceLinks")]
    public IReadOnlyList<EvidenceLinkResponse>? EvidenceLinks { get; init; }

    /// <summary>
    /// Gets the proposed actions in this turn.
    /// </summary>
    [JsonPropertyName("proposedActions")]
    public IReadOnlyList<ProposedActionResponse>? ProposedActions { get; init; }

    /// <summary>
    /// Creates a response from a turn.
    /// </summary>
    public static ConversationTurnResponse FromTurn(ConversationTurn turn) => new()
    {
        TurnId = turn.TurnId,
        Role = turn.Role.ToString().ToLowerInvariant(),
        Content = turn.Content,
        Timestamp = turn.Timestamp,
        EvidenceLinks = turn.EvidenceLinks.IsEmpty
            ? null
            : turn.EvidenceLinks.Select(EvidenceLinkResponse.FromLink).ToList(),
        ProposedActions = turn.ProposedActions.IsEmpty
            ? null
            : turn.ProposedActions.Select(ProposedActionResponse.FromAction).ToList()
    };
}

/// <summary>
/// Response for an evidence link.
/// </summary>
public sealed record EvidenceLinkResponse
{
    /// <summary>
    /// Gets the link type (sbom, dsse, callGraph, reachability, etc.).
    /// </summary>
    [JsonPropertyName("type")]
    public required string Type { get; init; }

    /// <summary>
    /// Gets the URI.
    /// </summary>
    [JsonPropertyName("uri")]
    public required string Uri { get; init; }

    /// <summary>
    /// Gets the display label.
    /// </summary>
    [JsonPropertyName("label")]
    public string? Label { get; init; }

    /// <summary>
    /// Gets the confidence score.
    /// </summary>
    [JsonPropertyName("confidence")]
    public double? Confidence { get; init; }

    /// <summary>
    /// Creates a response from an evidence link.
    /// </summary>
    public static EvidenceLinkResponse FromLink(EvidenceLink link) => new()
    {
        Type = link.Type.ToString(),
        Uri = link.Uri,
        Label = link.Label,
        Confidence = link.Confidence
    };
}

/// <summary>
/// Response for a proposed action.
/// </summary>
public sealed record ProposedActionResponse
{
    /// <summary>
    /// Gets the action type (approve, quarantine, defer, generate_manifest, create_vex).
    /// </summary>
    [JsonPropertyName("actionType")]
    public required string ActionType { get; init; }

    /// <summary>
    /// Gets the action label.
    /// </summary>
    [JsonPropertyName("label")]
    public required string Label { get; init; }

    /// <summary>
    /// Gets the policy gate for this action.
    /// </summary>
    [JsonPropertyName("policyGate")]
    public string? PolicyGate { get; init; }

    /// <summary>
    /// Gets whether this action requires confirmation.
    /// </summary>
    [JsonPropertyName("requiresConfirmation")]
    public bool RequiresConfirmation { get; init; }

    /// <summary>
    /// Creates a response from a proposed action.
    /// </summary>
    public static ProposedActionResponse FromAction(ProposedAction action) => new()
    {
        ActionType = action.ActionType,
        Label = action.Label,
        PolicyGate = action.PolicyGate,
        RequiresConfirmation = action.RequiresConfirmation
    };
}

/// <summary>
/// Response for the assistant's turn (non-streaming).
/// </summary>
public sealed record AssistantTurnResponse
{
    /// <summary>
    /// Gets the turn ID.
    /// </summary>
    [JsonPropertyName("turnId")]
    public required string TurnId { get; init; }

    /// <summary>
    /// Gets the assistant's response content.
    /// </summary>
    [JsonPropertyName("content")]
    public required string Content { get; init; }

    /// <summary>
    /// Gets the timestamp.
    /// </summary>
    [JsonPropertyName("timestamp")]
    public required DateTimeOffset Timestamp { get; init; }

    /// <summary>
    /// Gets evidence links found in the response.
    /// </summary>
    [JsonPropertyName("evidenceLinks")]
    public IReadOnlyList<EvidenceLinkResponse>? EvidenceLinks { get; init; }

    /// <summary>
    /// Gets proposed actions in the response.
    /// </summary>
    [JsonPropertyName("proposedActions")]
    public IReadOnlyList<ProposedActionResponse>? ProposedActions { get; init; }

    /// <summary>
    /// Gets the grounding score (0.0-1.0).
    /// </summary>
    [JsonPropertyName("groundingScore")]
    public double GroundingScore { get; init; }

    /// <summary>
    /// Gets the token count.
    /// </summary>
    [JsonPropertyName("tokenCount")]
    public int TokenCount { get; init; }

    /// <summary>
    /// Gets the processing duration in milliseconds.
    /// </summary>
    [JsonPropertyName("durationMs")]
    public long DurationMs { get; init; }
}

/// <summary>
/// Response for listing conversations.
/// </summary>
public sealed record ConversationListResponse
{
    /// <summary>
    /// Gets the conversations.
    /// </summary>
    [JsonPropertyName("conversations")]
    public required IReadOnlyList<ConversationSummary> Conversations { get; init; }

    /// <summary>
    /// Gets the total count.
    /// </summary>
    [JsonPropertyName("totalCount")]
    public int TotalCount { get; init; }
}

/// <summary>
/// Summary of a conversation for listing.
/// </summary>
public sealed record ConversationSummary
{
    /// <summary>
    /// Gets the conversation ID.
    /// </summary>
    [JsonPropertyName("conversationId")]
    public required string ConversationId { get; init; }

    /// <summary>
    /// Gets the creation timestamp.
    /// </summary>
    [JsonPropertyName("createdAt")]
    public required DateTimeOffset CreatedAt { get; init; }

    /// <summary>
    /// Gets the last update timestamp.
    /// </summary>
    [JsonPropertyName("updatedAt")]
    public required DateTimeOffset UpdatedAt { get; init; }

    /// <summary>
    /// Gets the turn count.
    /// </summary>
    [JsonPropertyName("turnCount")]
    public int TurnCount { get; init; }

    /// <summary>
    /// Gets a preview of the first user message.
    /// </summary>
    [JsonPropertyName("preview")]
    public string? Preview { get; init; }
}