using System.Reflection;
using System.Text.Json;
using s8n_runtime.ViewModels;

string workflowViewFile = Environment.GetEnvironmentVariable("WORKFLOW_FILE")!;
string projectDirectory = Environment.GetEnvironmentVariable("PROJECT_DIR") ?? $"/sources";

if (string.IsNullOrEmpty(workflowViewFile) || !Directory.Exists(projectDirectory))
{
    AssemblyName a_name = Assembly.GetExecutingAssembly()!.GetName();
    Console.WriteLine("S8N Compiler, version: {0}.\nSpecify environment variables: WORKFLOW_FILE, PROJECT_DIR.\nCLR: {1}", a_name.Version, Environment.Version);
    return;
}

var workflow = JsonSerializer.Deserialize<S8nWorkflow>(File.OpenRead(workflowViewFile), JsonSerializerOptions.Web)!;

var edgesFile = Path.Combine("/sources", $"{workflow.Name}.Edges.cs");
var nodesFile = Path.Combine("/sources", $"{workflow.Name}.Nodes.cs");

// Linking
const string templateEdges = """
// !Warning! Please, don't change this file. Code autogenerated
#pragma warning disable CS8622 // Nullability of reference types in type of parameter doesn't match the target delegate (possibly because of nullability attributes).

public partial class {0}
{{
    public void Connect()
    {{
        // edges connect here >>>
        {1}
    }}

    public void Disconnect()
    {{
        // edges disconnect here >>>
        {2}
    }}
}}

""";
const string templateNodes = """
// !Warning! Please, don't change this file. Code autogenerated

public partial class {0}
{{
    // nodes here >>>
    
    {1}
}}
""";

static string GetConnection(WorkflowEdge edge) =>
    $"{edge.Source}{(string.IsNullOrEmpty(edge.SourceHandle) ? string.Empty : ".")}{edge.SourceHandle ?? string.Empty} {(
        edge.IsEvent ? "+" : string.Empty
        )}= {edge.Target}{(string.IsNullOrEmpty(edge.TargetHandle) ? string.Empty : ".")}{edge.TargetHandle ?? string.Empty}";

string edgesConnections = string.Join("\n", workflow.Edges.Select(e => $"// {e.Id}\n        {GetConnection(e)};"));
var edges = string.Format(templateEdges, workflow.Name, edgesConnections, edgesConnections.Replace('+', '-'));
string nodesFields = string.Join("\n    ", workflow.Nodes.Select(n => $"// {n.Data?.Label}\n    public {n.Class} {n.Id};"));
var nodes = string.Format(templateNodes, workflow.Name, nodesFields);

await File.WriteAllTextAsync(edgesFile, edges);
await File.WriteAllTextAsync(nodesFile, nodes);