using EngineeringSync.Domain.Constants;
using EngineeringSync.Domain.Entities;
using EngineeringSync.Infrastructure;
using EngineeringSync.Service.Hubs;
using EngineeringSync.Service.Models;
using EngineeringSync.Service.Services;
using Microsoft.AspNetCore.SignalR;
using Microsoft.EntityFrameworkCore;

namespace EngineeringSync.Service.Api;

public static class ProjectsApi
{
    public static IEndpointRouteBuilder MapProjectsApi(this IEndpointRouteBuilder app)
    {
        var group = app.MapGroup("/api/projects");

        group.MapGet("/", async (IDbContextFactory<AppDbContext> dbFactory) =>
        {
            await using var db = await dbFactory.CreateDbContextAsync();
            var projects = await db.Projects.OrderBy(p => p.Name).ToListAsync();
            return Results.Ok(projects);
        });

        group.MapGet("/{id:guid}", async (Guid id, IDbContextFactory<AppDbContext> dbFactory) =>
        {
            await using var db = await dbFactory.CreateDbContextAsync();
            var project = await db.Projects.FindAsync(id);
            return project is null ? Results.NotFound() : Results.Ok(project);
        });

        group.MapPost("/", async (CreateProjectRequest req, IDbContextFactory<AppDbContext> dbFactory,
            WatcherService watcher, IHubContext<NotificationHub> hubContext, ILoggerFactory loggerFactory) =>
        {
            var logger = loggerFactory.CreateLogger("ProjectsApi");
            if (!Directory.Exists(req.EngineeringPath))
                return Results.BadRequest($"Engineering-Pfad existiert nicht: {req.EngineeringPath}");
            if (!Directory.Exists(req.SimulationPath))
                return Results.BadRequest($"Simulations-Pfad existiert nicht: {req.SimulationPath}");

            await using var db = await dbFactory.CreateDbContextAsync();
            var project = new ProjectConfig
            {
                Name = req.Name,
                EngineeringPath = req.EngineeringPath,
                SimulationPath = req.SimulationPath,
                FileExtensions = req.FileExtensions,
                IsActive = req.IsActive,
                BackupEnabled = req.BackupEnabled,
                BackupPath = req.BackupPath,
                MaxBackupsPerFile = req.MaxBackupsPerFile
            };
            db.Projects.Add(project);
            await db.SaveChangesAsync();

            await watcher.StartWatchingAsync(project);
            _ = Task.Run(async () =>
            {
                try { await watcher.ScanExistingFilesAsync(project); }
                catch (Exception ex) { logger.LogError(ex, "Fehler beim initialen Scan für Projekt {Id}", project.Id); }
            });

            await hubContext.Clients.All.SendAsync(HubMethodNames.ProjectConfigChanged, CancellationToken.None);

            return Results.Created($"/api/projects/{project.Id}", project);
        });

        group.MapPut("/{id:guid}", async (Guid id, UpdateProjectRequest req,
            IDbContextFactory<AppDbContext> dbFactory, WatcherService watcher, IHubContext<NotificationHub> hubContext,
            ILoggerFactory loggerFactory) =>
        {
            var logger = loggerFactory.CreateLogger("ProjectsApi");
            await using var db = await dbFactory.CreateDbContextAsync();
            var project = await db.Projects.FindAsync(id);
            if (project is null) return Results.NotFound();

            if (!Directory.Exists(req.EngineeringPath))
                return Results.BadRequest($"Engineering-Pfad existiert nicht: {req.EngineeringPath}");
            if (!Directory.Exists(req.SimulationPath))
                return Results.BadRequest($"Simulations-Pfad existiert nicht: {req.SimulationPath}");

            project.Name = req.Name;
            project.EngineeringPath = req.EngineeringPath;
            project.SimulationPath = req.SimulationPath;
            project.FileExtensions = req.FileExtensions;
            project.IsActive = req.IsActive;
            project.BackupEnabled = req.BackupEnabled;
            project.BackupPath = req.BackupPath;
            project.MaxBackupsPerFile = req.MaxBackupsPerFile;
            await db.SaveChangesAsync();

            // Watcher neu starten (stoppt automatisch den alten)
            await watcher.StartWatchingAsync(project);
            _ = Task.Run(async () =>
            {
                try { await watcher.ScanExistingFilesAsync(project); }
                catch (Exception ex) { logger.LogError(ex, "Fehler beim initialen Scan für Projekt {Id}", project.Id); }
            });

            await hubContext.Clients.All.SendAsync(HubMethodNames.ProjectConfigChanged, CancellationToken.None);

            return Results.Ok(project);
        });

        group.MapDelete("/{id:guid}", async (Guid id, IDbContextFactory<AppDbContext> dbFactory,
            WatcherService watcher, IHubContext<NotificationHub> hubContext) =>
        {
            await using var db = await dbFactory.CreateDbContextAsync();
            var project = await db.Projects.FindAsync(id);
            if (project is null) return Results.NotFound();

            await watcher.StopWatchingAsync(id);
            db.Projects.Remove(project);
            await db.SaveChangesAsync();

            await hubContext.Clients.All.SendAsync(HubMethodNames.ProjectConfigChanged, CancellationToken.None);

            return Results.NoContent();
        });

        group.MapGet("/scan", async (string engineeringPath, string simulationPath, string fileExtensions) =>
        {
            if (!Directory.Exists(engineeringPath))
                return Results.BadRequest($"Engineering-Pfad existiert nicht: {engineeringPath}");
            if (!Directory.Exists(simulationPath))
                return Results.BadRequest($"Simulations-Pfad existiert nicht: {simulationPath}");

            var extensions = string.IsNullOrWhiteSpace(fileExtensions) || fileExtensions == "*"
                ? new HashSet<string>()
                : fileExtensions.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries)
                    .ToHashSet(StringComparer.OrdinalIgnoreCase);

            var scanAll = extensions.Count == 0;
            var engFiles = scanAll
                ? Directory.EnumerateFiles(engineeringPath, "*", SearchOption.AllDirectories).ToList()
                : Directory.EnumerateFiles(engineeringPath, "*", SearchOption.AllDirectories)
                    .Where(f => extensions.Contains(Path.GetExtension(f)))
                    .ToList();

            var results = new List<ScanResultEntry>();
            foreach (var engFile in engFiles)
            {
                var relativePath = Path.GetRelativePath(engineeringPath, engFile);
                var simFile = Path.Combine(simulationPath, relativePath);

                var engInfo = new FileInfo(engFile);
                var engHash = await FileHasher.ComputeAsync(engFile);

                var existsInSim = File.Exists(simFile);
                var needsSync = !existsInSim;
                if (existsInSim)
                {
                    var simHash = await FileHasher.ComputeAsync(simFile);
                    needsSync = engHash != simHash;
                }

                if (needsSync)
                {
                    results.Add(new ScanResultEntry(
                        relativePath,
                        existsInSim ? "Modified" : "Created",
                        engInfo.Length,
                        engInfo.LastWriteTimeUtc
                    ));
                }
            }

            return Results.Ok(results);
        });

        return app;
    }
}