package a2a

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/nomadcode/nomadcode-core/internal/agent"
)

func TestSendMessagePostsJSONRPCMessageSend(t *testing.T) {
	var gotAuth string
	var gotReq jsonRPCRequest
	var gotParams map[string]any

	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		gotAuth = r.Header.Get("Authorization")
		if err := json.NewDecoder(r.Body).Decode(&gotReq); err != nil {
			t.Fatalf("decode request: %v", err)
		}
		paramsBytes, _ := json.Marshal(gotReq.Params)
		if err := json.Unmarshal(paramsBytes, &gotParams); err != nil {
			t.Fatalf("decode params: %v", err)
		}
		_, _ = w.Write([]byte(`{
			"jsonrpc": "2.0",
			"id": "nomadcode-1",
			"result": {
				"kind": "task",
				"id": "task-1",
				"contextId": "ctx-1",
				"status": {"state": "working"}
			}
		}`))
	}))
	defer server.Close()

	client := NewClient(Config{URL: server.URL, Token: "secret"}, nil)
	result, err := client.SendMessage(context.Background(), agent.SendMessageInput{
		Text:                "fix issue",
		ContextID:           "ctx-1",
		AcceptedOutputModes: []string{"text/plain"},
		Blocking:            true,
		Metadata: map[string]any{
			"nomad_task_id": "task-local",
		},
	})
	if err != nil {
		t.Fatalf("SendMessage returned error: %v", err)
	}

	if gotAuth != "Bearer secret" {
		t.Fatalf("unexpected auth header: %q", gotAuth)
	}
	if gotReq.JSONRPC != "2.0" || gotReq.Method != "message/send" || gotReq.ID != "nomadcode-1" {
		t.Fatalf("unexpected json-rpc request: %#v", gotReq)
	}
	message := gotParams["message"].(map[string]any)
	if message["role"] != "user" || message["kind"] != "message" || message["contextId"] != "ctx-1" {
		t.Fatalf("unexpected message: %#v", message)
	}
	parts := message["parts"].([]any)
	part := parts[0].(map[string]any)
	if part["kind"] != "text" || part["text"] != "fix issue" {
		t.Fatalf("unexpected part: %#v", part)
	}
	config := gotParams["configuration"].(map[string]any)
	if config["blocking"] != true {
		t.Fatalf("expected blocking=true, got %#v", config["blocking"])
	}
	metadata := gotParams["metadata"].(map[string]any)
	if metadata["nomad_task_id"] != "task-local" {
		t.Fatalf("unexpected metadata: %#v", metadata)
	}
	if result.Task == nil || result.Task.ID != "task-1" || result.Task.Status.State != agent.TaskStateWorking {
		t.Fatalf("unexpected result: %#v", result)
	}
}

func TestSendMessageReturnsDirectMessage(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		_, _ = w.Write([]byte(`{
			"jsonrpc": "2.0",
			"id": "nomadcode-1",
			"result": {
				"kind": "message",
				"role": "agent",
				"messageId": "msg-2",
				"parts": [{"kind": "text", "text": "done"}]
			}
		}`))
	}))
	defer server.Close()

	client := NewClient(Config{URL: server.URL}, nil)
	result, err := client.SendMessage(context.Background(), agent.SendMessageInput{Text: "status"})
	if err != nil {
		t.Fatalf("SendMessage returned error: %v", err)
	}
	if result.Message == nil || result.Message.Role != "agent" || result.Message.Parts[0].Text != "done" {
		t.Fatalf("unexpected result: %#v", result)
	}
}

func TestGetAndCancelTask(t *testing.T) {
	var methods []string
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var req jsonRPCRequest
		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
			t.Fatalf("decode request: %v", err)
		}
		methods = append(methods, req.Method)
		_, _ = w.Write([]byte(`{
			"jsonrpc": "2.0",
			"id": "` + req.ID + `",
			"result": {
				"kind": "task",
				"id": "task-1",
				"status": {"state": "completed"}
			}
		}`))
	}))
	defer server.Close()

	client := NewClient(Config{URL: server.URL}, nil)
	task, err := client.GetTask(context.Background(), agent.GetTaskInput{TaskID: "task-1"})
	if err != nil {
		t.Fatalf("GetTask returned error: %v", err)
	}
	if task.Status.State != agent.TaskStateCompleted {
		t.Fatalf("unexpected get task: %#v", task)
	}

	task, err = client.CancelTask(context.Background(), agent.CancelTaskInput{TaskID: "task-1"})
	if err != nil {
		t.Fatalf("CancelTask returned error: %v", err)
	}
	if task.ID != "task-1" {
		t.Fatalf("unexpected cancel task: %#v", task)
	}
	if len(methods) != 2 || methods[0] != "tasks/get" || methods[1] != "tasks/cancel" {
		t.Fatalf("unexpected methods: %#v", methods)
	}
}

func TestJSONRPCError(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		_, _ = w.Write([]byte(`{
			"jsonrpc": "2.0",
			"id": "nomadcode-1",
			"error": {"code": -32602, "message": "invalid params"}
		}`))
	}))
	defer server.Close()

	client := NewClient(Config{URL: server.URL}, nil)
	if _, err := client.SendMessage(context.Background(), agent.SendMessageInput{Text: "hello"}); err == nil {
		t.Fatal("expected JSON-RPC error")
	}
}