using System.Text.Json;
using Microsoft.AspNetCore.Mvc;
using w4c_workflows.Services;

namespace w4c_workflows.Controllers;

/// <summary>
/// Per-tenant operator API keys. This whole surface authenticates with the
/// tenant's MAIN JWT (see AuthMiddleware) so a logged-in owner can mint, list,
/// rotate and revoke the keys that the frontend/worker then use everywhere else.
/// </summary>
[ApiController]
[Route("api/keys")]
public class KeysController : ControllerBase
{
    private static readonly string[] AllScopes = { "manage", "run", "read" };

    private readonly ApiKeyService _keys;
    private readonly ILogger<KeysController> _logger;

    public KeysController(ApiKeyService keys, ILogger<KeysController> logger)
    {
        _keys = keys;
        _logger = logger;
    }

    private string TenantId => (string?)HttpContext.Items["TenantId"]
        ?? throw new InvalidOperationException("TenantId not resolved by auth middleware");

    public sealed record MintRequest(string? Label = null, string[]? Scopes = null);

    /// <summary>
    /// Mints the tenant's first operator key. Idempotent-by-guard: fails with
    /// 409 once any active key exists — subsequent keys are created via
    /// POST /api/keys (rotate).
    /// </summary>
    [HttpPost("bootstrap")]
    public async Task<IActionResult> Bootstrap(CancellationToken ct)
    {
        if (await _keys.CountActiveAsync(TenantId, ct) > 0)
            return Conflict(new { error = "Operator keys already exist — use POST /api/keys to rotate." });

        var (id, raw) = await _keys.MintAsync(TenantId, "default", AllScopes, ct);
        _logger.LogInformation("Bootstrapped operator key {KeyId} for tenant {TenantId}", id, TenantId);
        return Ok(new { id, key = raw, scopes = AllScopes, note = "Store this key now — it is shown only once." });
    }

    /// <summary>Mints a new operator key (rotation).</summary>
    [HttpPost]
    public async Task<IActionResult> Mint([FromBody] MintRequest? request, CancellationToken ct)
    {
        var label = string.IsNullOrWhiteSpace(request?.Label) ? "default" : request.Label.Trim();
        var scopes = NormalizeScopes(request?.Scopes);

        var (id, raw) = await _keys.MintAsync(TenantId, label, scopes, ct);
        _logger.LogInformation("Minted operator key {KeyId} for tenant {TenantId}", id, TenantId);
        return Ok(new { id, key = raw, scopes, note = "Store this key now — it is shown only once." });
    }

    /// <summary>Lists the tenant's keys (hashes are never exposed).</summary>
    [HttpGet]
    public async Task<IActionResult> List(CancellationToken ct)
    {
        var keys = await _keys.ListAsync(TenantId, ct);
        var result = keys.Select(k => new
        {
            k.Id,
            k.Label,
            scopes = ParseScopes(k.ScopesJson),
            k.CreatedAt,
            k.LastUsedAt,
            k.RevokedAt,
            active = k.RevokedAt == null,
        });
        return Ok(result);
    }

    /// <summary>Revokes an operator key.</summary>
    [HttpDelete("{id:guid}")]
    public async Task<IActionResult> Revoke(Guid id, CancellationToken ct)
    {
        var revoked = await _keys.RevokeAsync(TenantId, id, ct);
        if (!revoked)
            return NotFound(new { error = "Key not found." });

        _logger.LogInformation("Revoked operator key {KeyId} for tenant {TenantId}", id, TenantId);
        return NoContent();
    }

    private static string[] NormalizeScopes(string[]? requested)
    {
        if (requested == null || requested.Length == 0)
            return AllScopes;

        var valid = new HashSet<string> { "manage", "run", "read" };
        var normalized = requested.Where(s => valid.Contains(s)).Distinct().ToArray();
        return normalized.Length == 0 ? AllScopes : normalized;
    }

    private static string[] ParseScopes(string? json)
    {
        if (string.IsNullOrWhiteSpace(json))
            return Array.Empty<string>();
        try
        {
            return JsonSerializer.Deserialize<string[]>(json) ?? Array.Empty<string>();
        }
        catch
        {
            return Array.Empty<string>();
        }
    }
}