using System.Linq;
using System.Text.Json;
using System.Threading.Tasks;
using Gott.Services;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;

namespace Gott.Endpoints;

public static class SkillEndpoint
{
    public static void MapSkillEndpoints(this IEndpointRouteBuilder app)
    {
        // Skills (Dateisystem-basiert)
        app.MapGet("/api/skills", HandleListSkills);

        // Agent ↔ Skill Zuordnung
        app.MapGet("/api/agents/{agentId}/skills", HandleGetAgentSkills);
        app.MapPut("/api/agents/{agentId}/skills", HandleSetAgentSkills);
        app.MapPost("/api/agents/{agentId}/skills/{slug}", HandleAddAgentSkill);
        app.MapDelete("/api/agents/{agentId}/skills/{slug}", HandleRemoveAgentSkill);
    }

    private static async Task HandleListSkills(HttpContext ctx, SkillService skillService)
    {
        var skills = skillService.GetAllSkills();
        await ctx.Response.WriteAsJsonAsync(skills);
    }

    private static async Task HandleGetAgentSkills(HttpContext ctx, DatabaseService db, SkillService skillService)
    {
        var agentId = ctx.Request.RouteValues["agentId"]?.ToString();
        if (string.IsNullOrEmpty(agentId)) { ctx.Response.StatusCode = 400; return; }

        var slugs = await db.GetAgentSkills(agentId);
        var allSkills = skillService.GetAllSkills();

        // Nur Skills zurückgeben die auch wirklich existieren
        var result = allSkills
            .Where(s => slugs.Contains(s.Slug))
            .ToList();

        await ctx.Response.WriteAsJsonAsync(result);
    }

    private static async Task HandleSetAgentSkills(HttpContext ctx, DatabaseService db)
    {
        var agentId = ctx.Request.RouteValues["agentId"]?.ToString();
        if (string.IsNullOrEmpty(agentId)) { ctx.Response.StatusCode = 400; return; }

        var body = await JsonSerializer.DeserializeAsync<JsonElement>(ctx.Request.Body);
        var slugs = body.TryGetProperty("skills", out var arr)
            ? arr.EnumerateArray().Select(e => e.GetString()).Where(s => !string.IsNullOrEmpty(s)).ToList()
            : new System.Collections.Generic.List<string>();

        await db.SetAgentSkills(agentId, slugs);

        var updated = await db.GetAgentSkills(agentId);
        await ctx.Response.WriteAsJsonAsync(updated);
    }

    private static async Task HandleAddAgentSkill(HttpContext ctx, DatabaseService db)
    {
        var agentId = ctx.Request.RouteValues["agentId"]?.ToString();
        var slug = ctx.Request.RouteValues["slug"]?.ToString();
        if (string.IsNullOrEmpty(agentId) || string.IsNullOrEmpty(slug)) { ctx.Response.StatusCode = 400; return; }

        await db.AddAgentSkill(agentId, slug);
        ctx.Response.StatusCode = 204;
    }

    private static async Task HandleRemoveAgentSkill(HttpContext ctx, DatabaseService db)
    {
        var agentId = ctx.Request.RouteValues["agentId"]?.ToString();
        var slug = ctx.Request.RouteValues["slug"]?.ToString();
        if (string.IsNullOrEmpty(agentId) || string.IsNullOrEmpty(slug)) { ctx.Response.StatusCode = 400; return; }

        await db.RemoveAgentSkill(agentId, slug);
        ctx.Response.StatusCode = 204;
    }
}