using ControlPlane.Api.Services;
using ControlPlane.Core.Services;
using System.Text.Json;

namespace ControlPlane.Api.Endpoints;

public static class ReleaseEndpoints
{
    private static readonly JsonSerializerOptions JsonOpts = new(JsonSerializerDefaults.Web)
    {
        Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() },
    };

    public static IEndpointRouteBuilder MapReleaseEndpoints(this IEndpointRouteBuilder app)
    {
        var group = app.MapGroup("/api/release").WithTags("Release");
        group.MapGet("/history",       GetHistory);
        group.MapPost("/{env}",        TriggerRelease);
        return app;
    }

    private static async Task<IResult> GetHistory(BuildHistoryService history) =>
        Results.Ok(await history.GetReleasesAsync());

    /// <summary>
    /// Triggers a rolling redeploy of all managed containers in the target env.
    /// Streams SSE lines until release is complete.
    /// Valid env values: fdev | uat | prod | all
    /// </summary>
    private static async Task TriggerRelease(
        string env,
        HttpContext ctx,
        ReleaseService releases,
        CancellationToken ct)
    {
        var valid = new[] { "fdev", "uat", "prod", "all" };
        if (!valid.Contains(env, StringComparer.OrdinalIgnoreCase))
        {
            ctx.Response.StatusCode = 400;
            await ctx.Response.WriteAsJsonAsync(
                new { error = $"Invalid environment '{env}'. Valid: fdev, uat, prod, all." }, ct);
            return;
        }

        ctx.Response.Headers.ContentType  = "text/event-stream";
        ctx.Response.Headers.CacheControl = "no-cache";
        ctx.Response.Headers.Connection   = "keep-alive";

        async Task Send(object payload)
        {
            var json = JsonSerializer.Serialize(payload, JsonOpts);
            await ctx.Response.WriteAsync($"data: {json}\n\n", ct);
            await ctx.Response.Body.FlushAsync(ct);
        }

        void OnLine(string line) => Send(new { line }).GetAwaiter().GetResult();

        var record = await releases.ReleaseAsync(env, OnLine, ct);

        await Send(new { done = true, release = record });
    }
}