package mcpclient_test

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

	"github.com/mathiasbq/supervisor/internal/mcpclient"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestCallTool_Success(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, http.MethodPost, r.Method)
		assert.Equal(t, "Bearer tok", r.Header.Get("Authorization"))
		b, _ := io.ReadAll(r.Body)
		var got map[string]any
		_ = json.Unmarshal(b, &got)
		assert.Equal(t, "tools/call", got["method"])
		params := got["params"].(map[string]any)
		assert.Equal(t, "x_y", params["name"])

		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"jsonrpc":"2.0","id":1,"result":{"content":[{"type":"text","text":"{\"ok\":true,\"n\":7}"}]}}`))
	}))
	defer srv.Close()

	c := mcpclient.New(srv.URL, "tok")
	var out struct {
		OK bool `json:"ok"`
		N  int  `json:"n"`
	}
	err := c.CallTool(context.Background(), "x_y", map[string]any{"a": 1}, &out)
	require.NoError(t, err)
	assert.True(t, out.OK)
	assert.Equal(t, 7, out.N)
}

func TestCallTool_RPCError(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"jsonrpc":"2.0","id":1,"error":{"code":-32003,"message":"already exists"}}`))
	}))
	defer srv.Close()

	c := mcpclient.New(srv.URL, "")
	err := c.CallTool(context.Background(), "x", nil, nil)
	require.Error(t, err)
	var me *mcpclient.Error
	require.True(t, errors.As(err, &me))
	assert.Equal(t, -32003, me.Code)
	assert.Contains(t, me.Message, "already exists")
}

func TestCallTool_HTTPError(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusUnauthorized)
		_, _ = w.Write([]byte(`unauthorized`))
	}))
	defer srv.Close()

	c := mcpclient.New(srv.URL, "")
	err := c.CallTool(context.Background(), "x", nil, nil)
	require.Error(t, err)
	assert.Contains(t, err.Error(), "401")
}

func TestCallTool_NilResult(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"jsonrpc":"2.0","id":1,"result":{"content":[{"type":"text","text":"{}"}]}}`))
	}))
	defer srv.Close()

	c := mcpclient.New(srv.URL, "")
	require.NoError(t, c.CallTool(context.Background(), "x", nil, nil))
}