// package api handles launcher-specific API calls to the backend.
package api

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

	"gitea.mrixs.me/Mrixs/MrixsCraft-launcher/internal/ui/screens"
	"github.com/stretchr/testify/require"
)

func TestFetchServerList_Success(t *testing.T) {
	// Arrange - create mock server response
	serverResp := ServerResponse{
		Servers: []ServerInfo{
			{Slug: "hitech", Name: "HiTech 1.21", Version: "1.21", IP: "192.168.1.100"},
			{Slug: "vanilla", Name: "Vanilla 1.20", Version: "1.20", IP: "192.168.1.101"},
		},
	}

	// Create test server with mock response
	testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/servers.json" {
			t.Errorf("unexpected path: %s", r.URL.Path)
			w.WriteHeader(http.StatusNotFound)
			return
		}
		if r.Method != http.MethodGet {
			t.Errorf("unexpected method: %s", r.Method)
			w.WriteHeader(http.StatusMethodNotAllowed)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(serverResp)
	}))
	defer testServer.Close()

	// Act - call FetchServerList with test server URL
	modpacks, err := FetchServerList(testServer.URL)
	require.NoError(t, err)

	// Assert - check results
	require.Len(t, modpacks, 2)
	require.Equal(t, screens.Modpack{Slug: "hitech", Name: "HiTech 1.21"}, modpacks[0])
	require.Equal(t, screens.Modpack{Slug: "vanilla", Name: "Vanilla 1.20"}, modpacks[1])
}

func TestFetchServerList_EmptyList(t *testing.T) {
	// Arrange - create mock server with empty servers list
	serverResp := ServerResponse{Servers: []ServerInfo{}}

	// Create test server with mock response
	testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/servers.json" {
			t.Errorf("unexpected path: %s", r.URL.Path)
			w.WriteHeader(http.StatusNotFound)
			return
		}
		if r.Method != http.MethodGet {
			t.Errorf("unexpected method: %s", r.Method)
			w.WriteHeader(http.StatusMethodNotAllowed)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(serverResp)
	}))
	defer testServer.Close()

	// Act - call FetchServerList with test server URL
	modpacks, err := FetchServerList(testServer.URL)
	require.NoError(t, err)

	// Assert - should return empty slice
	require.Empty(t, modpacks)
}

func TestFetchServerList_NetworkError(t *testing.T) {
	// Act - call FetchServerList with invalid URL that will fail to connect
	modpacks, err := FetchServerList("http://localhost:12345/api/servers.json") // Assuming no server on this port

	// Assert - should return error
	require.Error(t, err)
	require.Nil(t, modpacks)
	require.Contains(t, err.Error(), "making request")
}

func TestFetchServerList_HTTPError(t *testing.T) {
	// Arrange - create test server that returns 500 error
	testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
	}))
	defer testServer.Close()

	// Act - call FetchServerList with test server URL
	modpacks, err := FetchServerList(testServer.URL)
	require.Error(t, err)
	require.Nil(t, modpacks)
	require.Contains(t, err.Error(), "unexpected status code: 500")
}

func TestFetchServerList_InvalidJSON(t *testing.T) {
	// Arrange - create test server that returns invalid JSON
	testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"invalid": json}`))
	}))
	defer testServer.Close()

	// Act - call FetchServerList with test server URL
	modpacks, err := FetchServerList(testServer.URL)
	require.Error(t, err)
	require.Nil(t, modpacks)
	require.Contains(t, err.Error(), "decoding JSON")
}

func TestFetchServerList_Timeout(t *testing.T) {
	// Arrange - create test server that delays response to trigger timeout
	testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Sleep longer than our timeout to trigger timeout error
		time.Sleep(15 * time.Second)
	}))
	defer testServer.Close()

	// Act - call FetchServerList with test server URL
	modpacks, err := FetchServerList(testServer.URL)
	require.Error(t, err)
	require.Nil(t, modpacks)
	require.Contains(t, err.Error(), "context deadline exceeded")
	require.Contains(t, err.Error(), "making request")
}