using System.CommandLine;
using System.Text.Json;
using Microsoft.Extensions.Logging;
using StellaOps.Cli.Extensions;

namespace StellaOps.Cli.Commands.Proof;

/// <summary>
/// Command group for key rotation operations.
/// Sprint: SPRINT_0501_0008_0001_proof_chain_key_rotation
/// Task: PROOF-KEY-0011
/// Implements advisory §8.2 key rotation commands.
/// </summary>
public class KeyRotationCommandGroup
{
    private readonly ILogger<KeyRotationCommandGroup> _logger;

    private static readonly JsonSerializerOptions JsonOptions = new()
    {
        WriteIndented = true,
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
    };

    public KeyRotationCommandGroup(ILogger<KeyRotationCommandGroup> logger)
    {
        _logger = logger;
    }

    /// <summary>
    /// Build the key rotation command tree.
    /// </summary>
    public Command BuildCommand()
    {
        var keyCommand = new Command("key", "Key management and rotation commands");

        keyCommand.Add(BuildListCommand());
        keyCommand.Add(BuildAddCommand());
        keyCommand.Add(BuildRevokeCommand());
        keyCommand.Add(BuildRotateCommand());
        keyCommand.Add(BuildStatusCommand());
        keyCommand.Add(BuildHistoryCommand());
        keyCommand.Add(BuildVerifyCommand());

        return keyCommand;
    }

    private Command BuildListCommand()
    {
        var anchorArg = new Argument<Guid>("anchorId")
        {
            Description = "Trust anchor ID"
        };

        var includeRevokedOption = new Option<bool>("--include-revoked")
        {
            Description = "Include revoked keys in output"
        }.SetDefaultValue(false);

        var outputOption = new Option<string>("--output")
        {
            Description = "Output format: text, json"
        }.SetDefaultValue("text").FromAmong("text", "json");

        var listCommand = new Command("list", "List keys for a trust anchor")
        {
            anchorArg,
            includeRevokedOption,
            outputOption
        };

        listCommand.SetAction(async (parseResult, ct) =>
        {
            var anchorId = parseResult.GetValue(anchorArg);
            var includeRevoked = parseResult.GetValue(includeRevokedOption);
            var output = parseResult.GetValue(outputOption) ?? "text";
            Environment.ExitCode = await ListKeysAsync(anchorId, includeRevoked, output, ct).ConfigureAwait(false);
        });

        return listCommand;
    }

    private Command BuildAddCommand()
    {
        var anchorArg = new Argument<Guid>("anchorId")
        {
            Description = "Trust anchor ID"
        };

        var keyIdArg = new Argument<string>("keyId")
        {
            Description = "New key ID"
        };

        var algorithmOption = new Option<string>("--algorithm", new[] { "-a" })
        {
            Description = "Key algorithm: Ed25519, ES256, ES384, RS256"
        }.SetDefaultValue("Ed25519").FromAmong("Ed25519", "ES256", "ES384", "RS256");

        var publicKeyOption = new Option<string?>("--public-key")
        {
            Description = "Path to public key file (PEM format)"
        };

        var notesOption = new Option<string?>("--notes")
        {
            Description = "Human-readable notes about the key"
        };

        var addCommand = new Command("add", "Add a new key to a trust anchor")
        {
            anchorArg,
            keyIdArg,
            algorithmOption,
            publicKeyOption,
            notesOption
        };

        addCommand.SetAction(async (parseResult, ct) =>
        {
            var anchorId = parseResult.GetValue(anchorArg);
            var keyId = parseResult.GetValue(keyIdArg);
            var algorithm = parseResult.GetValue(algorithmOption) ?? "Ed25519";
            var publicKeyPath = parseResult.GetValue(publicKeyOption);
            var notes = parseResult.GetValue(notesOption);
            Environment.ExitCode = await AddKeyAsync(anchorId, keyId, algorithm, publicKeyPath, notes, ct).ConfigureAwait(false);
        });

        return addCommand;
    }

    private Command BuildRevokeCommand()
    {
        var anchorArg = new Argument<Guid>("anchorId")
        {
            Description = "Trust anchor ID"
        };

        var keyIdArg = new Argument<string>("keyId")
        {
            Description = "Key ID to revoke"
        };

        var reasonOption = new Option<string>("--reason", new[] { "-r" })
        {
            Description = "Reason for revocation"
        }.SetDefaultValue("rotation-complete");

        var effectiveOption = new Option<DateTimeOffset?>("--effective-at")
        {
            Description = "Effective revocation time (default: now). ISO-8601 format."
        };

        var forceOption = new Option<bool>("--force")
        {
            Description = "Skip confirmation prompt"
        }.SetDefaultValue(false);

        var revokeCommand = new Command("revoke", "Revoke a key from a trust anchor")
        {
            anchorArg,
            keyIdArg,
            reasonOption,
            effectiveOption,
            forceOption
        };

        revokeCommand.SetAction(async (parseResult, ct) =>
        {
            var anchorId = parseResult.GetValue(anchorArg);
            var keyId = parseResult.GetValue(keyIdArg);
            var reason = parseResult.GetValue(reasonOption) ?? "rotation-complete";
            var effectiveAt = parseResult.GetValue(effectiveOption) ?? DateTimeOffset.UtcNow;
            var force = parseResult.GetValue(forceOption);
            Environment.ExitCode = await RevokeKeyAsync(anchorId, keyId, reason, effectiveAt, force, ct).ConfigureAwait(false);
        });

        return revokeCommand;
    }

    private Command BuildRotateCommand()
    {
        var anchorArg = new Argument<Guid>("anchorId")
        {
            Description = "Trust anchor ID"
        };

        var oldKeyIdArg = new Argument<string>("oldKeyId")
        {
            Description = "Old key ID to replace"
        };

        var newKeyIdArg = new Argument<string>("newKeyId")
        {
            Description = "New key ID"
        };

        var algorithmOption = new Option<string>("--algorithm", new[] { "-a" })
        {
            Description = "Key algorithm: Ed25519, ES256, ES384, RS256"
        }.SetDefaultValue("Ed25519").FromAmong("Ed25519", "ES256", "ES384", "RS256");

        var publicKeyOption = new Option<string?>("--public-key")
        {
            Description = "Path to new public key file (PEM format)"
        };

        var overlapOption = new Option<int>("--overlap-days")
        {
            Description = "Days to keep both keys active before revoking old"
        }.SetDefaultValue(30);

        var rotateCommand = new Command("rotate", "Rotate a key (add new, schedule old revocation)")
        {
            anchorArg,
            oldKeyIdArg,
            newKeyIdArg,
            algorithmOption,
            publicKeyOption,
            overlapOption
        };

        rotateCommand.SetAction(async (parseResult, ct) =>
        {
            var anchorId = parseResult.GetValue(anchorArg);
            var oldKeyId = parseResult.GetValue(oldKeyIdArg);
            var newKeyId = parseResult.GetValue(newKeyIdArg);
            var algorithm = parseResult.GetValue(algorithmOption) ?? "Ed25519";
            var publicKeyPath = parseResult.GetValue(publicKeyOption);
            var overlapDays = parseResult.GetValue(overlapOption);
            Environment.ExitCode = await RotateKeyAsync(anchorId, oldKeyId, newKeyId, algorithm, publicKeyPath, overlapDays, ct).ConfigureAwait(false);
        });

        return rotateCommand;
    }

    private Command BuildStatusCommand()
    {
        var anchorArg = new Argument<Guid>("anchorId")
        {
            Description = "Trust anchor ID"
        };

        var outputOption = new Option<string>("--output")
        {
            Description = "Output format: text, json"
        }.SetDefaultValue("text").FromAmong("text", "json");

        var statusCommand = new Command("status", "Show key rotation status and warnings")
        {
            anchorArg,
            outputOption
        };

        statusCommand.SetAction(async (parseResult, ct) =>
        {
            var anchorId = parseResult.GetValue(anchorArg);
            var output = parseResult.GetValue(outputOption) ?? "text";
            Environment.ExitCode = await ShowStatusAsync(anchorId, output, ct).ConfigureAwait(false);
        });

        return statusCommand;
    }

    private Command BuildHistoryCommand()
    {
        var anchorArg = new Argument<Guid>("anchorId")
        {
            Description = "Trust anchor ID"
        };

        var keyIdOption = new Option<string?>("--key-id", new[] { "-k" })
        {
            Description = "Filter by specific key ID"
        };

        var limitOption = new Option<int>("--limit")
        {
            Description = "Maximum entries to show"
        }.SetDefaultValue(50);

        var outputOption = new Option<string>("--output")
        {
            Description = "Output format: text, json"
        }.SetDefaultValue("text").FromAmong("text", "json");

        var historyCommand = new Command("history", "Show key audit history")
        {
            anchorArg,
            keyIdOption,
            limitOption,
            outputOption
        };

        historyCommand.SetAction(async (parseResult, ct) =>
        {
            var anchorId = parseResult.GetValue(anchorArg);
            var keyId = parseResult.GetValue(keyIdOption);
            var limit = parseResult.GetValue(limitOption);
            var output = parseResult.GetValue(outputOption) ?? "text";
            Environment.ExitCode = await ShowHistoryAsync(anchorId, keyId, limit, output, ct).ConfigureAwait(false);
        });

        return historyCommand;
    }

    private Command BuildVerifyCommand()
    {
        var anchorArg = new Argument<Guid>("anchorId")
        {
            Description = "Trust anchor ID"
        };

        var keyIdArg = new Argument<string>("keyId")
        {
            Description = "Key ID to verify"
        };

        var signedAtOption = new Option<DateTimeOffset?>("--signed-at", new[] { "-t" })
        {
            Description = "Verify key was valid at this time (ISO-8601)"
        };

        var verifyCommand = new Command("verify", "Verify a key's validity at a point in time")
        {
            anchorArg,
            keyIdArg,
            signedAtOption
        };

        verifyCommand.SetAction(async (parseResult, ct) =>
        {
            var anchorId = parseResult.GetValue(anchorArg);
            var keyId = parseResult.GetValue(keyIdArg);
            var signedAt = parseResult.GetValue(signedAtOption) ?? DateTimeOffset.UtcNow;
            Environment.ExitCode = await VerifyKeyAsync(anchorId, keyId, signedAt, ct).ConfigureAwait(false);
        });

        return verifyCommand;
    }

    #region Handler Implementations

    private async Task<int> ListKeysAsync(Guid anchorId, bool includeRevoked, string output, CancellationToken ct)
    {
        try
        {
            _logger.LogInformation("Listing keys for anchor {AnchorId}, includeRevoked={IncludeRevoked}",
                anchorId, includeRevoked);

            // TODO: Wire up to IKeyRotationService when DI is available

            if (output == "json")
            {
                var result = new
                {
                    anchorId = anchorId.ToString(),
                    activeKeys = Array.Empty<object>(),
                    revokedKeys = includeRevoked ? Array.Empty<object>() : null
                };
                Console.WriteLine(JsonSerializer.Serialize(result, JsonOptions));
            }
            else
            {
                Console.WriteLine($"Keys for Trust Anchor: {anchorId}");
                Console.WriteLine("═════════════════════════════════════════════");
                Console.WriteLine();
                Console.WriteLine("Active Keys:");
                Console.WriteLine("  (No active keys found - connect to service)");
                if (includeRevoked)
                {
                    Console.WriteLine();
                    Console.WriteLine("Revoked Keys:");
                    Console.WriteLine("  (No revoked keys found - connect to service)");
                }
            }

            return ProofExitCodes.Success;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to list keys for anchor {AnchorId}", anchorId);
            return ProofExitCodes.SystemError;
        }
    }

    private async Task<int> AddKeyAsync(Guid anchorId, string keyId, string algorithm, string? publicKeyPath, string? notes, CancellationToken ct)
    {
        try
        {
            _logger.LogInformation("Adding key {KeyId} to anchor {AnchorId}", keyId, anchorId);

            string? publicKey = null;
            if (publicKeyPath != null)
            {
                if (!File.Exists(publicKeyPath))
                {
                    Console.Error.WriteLine($"Error: Public key file not found: {publicKeyPath}");
                    return ProofExitCodes.SystemError;
                }
                publicKey = await File.ReadAllTextAsync(publicKeyPath, ct);
            }

            // TODO: Wire up to IKeyRotationService.AddKeyAsync

            Console.WriteLine("Adding key to trust anchor...");
            Console.WriteLine($"  Anchor: {anchorId}");
            Console.WriteLine($"  Key ID: {keyId}");
            Console.WriteLine($"  Algorithm: {algorithm}");
            Console.WriteLine($"  Public Key: {(publicKey != null ? "Provided" : "Not specified")}");
            if (notes != null)
                Console.WriteLine($"  Notes: {notes}");
            Console.WriteLine();
            Console.WriteLine("✓ Key added successfully (simulation)");

            return ProofExitCodes.Success;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to add key {KeyId} to anchor {AnchorId}", keyId, anchorId);
            return ProofExitCodes.SystemError;
        }
    }

    private async Task<int> RevokeKeyAsync(Guid anchorId, string keyId, string reason, DateTimeOffset effectiveAt, bool force, CancellationToken ct)
    {
        try
        {
            _logger.LogInformation("Revoking key {KeyId} from anchor {AnchorId}", keyId, anchorId);

            if (!force)
            {
                Console.Write($"Revoke key '{keyId}' from anchor {anchorId}? [y/N] ");
                var response = Console.ReadLine();
                if (response?.ToLowerInvariant() != "y")
                {
                    Console.WriteLine("Cancelled.");
                    return ProofExitCodes.Success;
                }
            }

            // TODO: Wire up to IKeyRotationService.RevokeKeyAsync

            Console.WriteLine("Revoking key...");
            Console.WriteLine($"  Anchor: {anchorId}");
            Console.WriteLine($"  Key ID: {keyId}");
            Console.WriteLine($"  Reason: {reason}");
            Console.WriteLine($"  Effective At: {effectiveAt:O}");
            Console.WriteLine();
            Console.WriteLine("✓ Key revoked successfully (simulation)");
            Console.WriteLine();
            Console.WriteLine("Note: Proofs signed before revocation remain valid.");

            return ProofExitCodes.Success;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to revoke key {KeyId} from anchor {AnchorId}", keyId, anchorId);
            return ProofExitCodes.SystemError;
        }
    }

    private async Task<int> RotateKeyAsync(Guid anchorId, string oldKeyId, string newKeyId, string algorithm, string? publicKeyPath, int overlapDays, CancellationToken ct)
    {
        try
        {
            _logger.LogInformation("Rotating key {OldKeyId} -> {NewKeyId} for anchor {AnchorId}",
                oldKeyId, newKeyId, anchorId);

            string? publicKey = null;
            if (publicKeyPath != null)
            {
                if (!File.Exists(publicKeyPath))
                {
                    Console.Error.WriteLine($"Error: Public key file not found: {publicKeyPath}");
                    return ProofExitCodes.SystemError;
                }
                publicKey = await File.ReadAllTextAsync(publicKeyPath, ct);
            }

            var revokeAt = DateTimeOffset.UtcNow.AddDays(overlapDays);

            // TODO: Wire up to IKeyRotationService

            Console.WriteLine("Key Rotation Plan");
            Console.WriteLine("═════════════════");
            Console.WriteLine($"  Anchor: {anchorId}");
            Console.WriteLine($"  Old Key: {oldKeyId}");
            Console.WriteLine($"  New Key: {newKeyId}");
            Console.WriteLine($"  Algorithm: {algorithm}");
            Console.WriteLine($"  Overlap Period: {overlapDays} days");
            Console.WriteLine($"  Old Key Revokes At: {revokeAt:O}");
            Console.WriteLine();
            Console.WriteLine("Step 1: Add new key to allowedKeyIds...");
            Console.WriteLine("  ✓ Key added (simulation)");
            Console.WriteLine();
            Console.WriteLine("Step 2: Schedule old key revocation...");
            Console.WriteLine($"  ✓ Old key will be revoked on {revokeAt:yyyy-MM-dd} (simulation)");
            Console.WriteLine();
            Console.WriteLine("✓ Key rotation initiated successfully");
            Console.WriteLine();
            Console.WriteLine("Next Steps:");
            Console.WriteLine($"  1. Start using '{newKeyId}' for new signatures");
            Console.WriteLine($"  2. Old key remains valid until {revokeAt:yyyy-MM-dd}");
            Console.WriteLine($"  3. Run 'stellaops key status {anchorId}' to check rotation warnings");

            return ProofExitCodes.Success;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to rotate key {OldKeyId} -> {NewKeyId} for anchor {AnchorId}",
                oldKeyId, newKeyId, anchorId);
            return ProofExitCodes.SystemError;
        }
    }

    private async Task<int> ShowStatusAsync(Guid anchorId, string output, CancellationToken ct)
    {
        try
        {
            _logger.LogInformation("Showing key status for anchor {AnchorId}", anchorId);

            // TODO: Wire up to IKeyRotationService.GetRotationWarningsAsync

            if (output == "json")
            {
                var result = new
                {
                    anchorId = anchorId.ToString(),
                    status = "healthy",
                    warnings = Array.Empty<object>()
                };
                Console.WriteLine(JsonSerializer.Serialize(result, JsonOptions));
            }
            else
            {
                Console.WriteLine($"Key Status for Trust Anchor: {anchorId}");
                Console.WriteLine("═════════════════════════════════════════════");
                Console.WriteLine();
                Console.WriteLine("Overall Status: ✓ Healthy (simulation)");
                Console.WriteLine();
                Console.WriteLine("Active Keys: 0");
                Console.WriteLine("Revoked Keys: 0");
                Console.WriteLine();
                Console.WriteLine("Rotation Warnings: None");
            }

            return ProofExitCodes.Success;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to show status for anchor {AnchorId}", anchorId);
            return ProofExitCodes.SystemError;
        }
    }

    private async Task<int> ShowHistoryAsync(Guid anchorId, string? keyId, int limit, string output, CancellationToken ct)
    {
        try
        {
            _logger.LogInformation("Showing key history for anchor {AnchorId}, keyId={KeyId}, limit={Limit}",
                anchorId, keyId, limit);

            // TODO: Wire up to IKeyRotationService.GetKeyHistoryAsync

            if (output == "json")
            {
                var result = new
                {
                    anchorId = anchorId.ToString(),
                    keyId = keyId,
                    entries = Array.Empty<object>()
                };
                Console.WriteLine(JsonSerializer.Serialize(result, JsonOptions));
            }
            else
            {
                Console.WriteLine($"Key Audit History for Trust Anchor: {anchorId}");
                if (keyId != null)
                    Console.WriteLine($"  Filtered by Key: {keyId}");
                Console.WriteLine("═════════════════════════════════════════════");
                Console.WriteLine();
                Console.WriteLine("Timestamp             | Operation  | Key ID        | Operator");
                Console.WriteLine("───────────────────────────────────────────────────────────────────");
                Console.WriteLine("(No history entries - connect to service)");
            }

            return ProofExitCodes.Success;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to show history for anchor {AnchorId}", anchorId);
            return ProofExitCodes.SystemError;
        }
    }

    private async Task<int> VerifyKeyAsync(Guid anchorId, string keyId, DateTimeOffset signedAt, CancellationToken ct)
    {
        try
        {
            _logger.LogInformation("Verifying key {KeyId} validity at {SignedAt} for anchor {AnchorId}",
                keyId, signedAt, anchorId);

            // TODO: Wire up to IKeyRotationService.CheckKeyValidityAsync

            Console.WriteLine($"Key Validity Check");
            Console.WriteLine("═════════════════════════════════════════════");
            Console.WriteLine($"  Anchor: {anchorId}");
            Console.WriteLine($"  Key ID: {keyId}");
            Console.WriteLine($"  Time:   {signedAt:O}");
            Console.WriteLine();
            Console.WriteLine("Result: ⚠ Unknown (connect to service for verification)");
            Console.WriteLine();
            Console.WriteLine("Temporal validation checks:");
            Console.WriteLine("  [ ] Key existed at specified time");
            Console.WriteLine("  [ ] Key was not revoked before specified time");
            Console.WriteLine("  [ ] Key algorithm is currently trusted");

            return ProofExitCodes.Success;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to verify key {KeyId} for anchor {AnchorId}", keyId, anchorId);
            return ProofExitCodes.SystemError;
        }
    }

    #endregion
}