package main

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
)

func releaseServer(t *testing.T, tag string, withInstaller bool) *httptest.Server {
	t.Helper()
	assets := ""
	if withInstaller {
		assets = fmt.Sprintf(`{"name":%q,"browser_download_url":"https://x/setup.exe"}`, windowsInstallerAsset)
	}
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = fmt.Fprintf(w, `{"tag_name":%q,"html_url":"https://x/release","assets":[%s]}`, tag, assets)
	}))
	t.Cleanup(srv.Close)
	return srv
}

func TestRunUpdate(t *testing.T) {
	tests := []struct {
		name          string
		current       string
		latest        string
		withInstaller bool
		goos          string
		checkOnly     bool
		assumeYes     bool
		stdin         string
		wantOut       []string
		wantInstall   bool
	}{
		{name: "up to date", current: "v1.0.5", latest: "v1.0.5", goos: "windows", withInstaller: true, wantOut: []string{"up to date"}},
		{name: "dev build never prompts", current: "dev", latest: "v9.0.0", goos: "windows", withInstaller: true, wantOut: []string{"up to date"}},
		{name: "check only", current: "v1.0.5", latest: "v1.0.6", goos: "windows", withInstaller: true, checkOnly: true, wantOut: []string{"v1.0.6", "https://x/release"}},
		{name: "non-windows shows url", current: "v1.0.5", latest: "v1.0.6", goos: "linux", withInstaller: true, wantOut: []string{"Download it from: https://x/release"}},
		{name: "windows without installer asset", current: "v1.0.5", latest: "v1.0.6", goos: "windows", wantOut: []string{"Download it from"}},
		{name: "windows prompt yes", current: "v1.0.5", latest: "v1.0.6", goos: "windows", withInstaller: true, stdin: "y\n", wantOut: []string{"[y/N]"}, wantInstall: true},
		{name: "windows prompt no", current: "v1.0.5", latest: "v1.0.6", goos: "windows", withInstaller: true, stdin: "n\n", wantOut: []string{"Skipped"}},
		{name: "windows prompt empty", current: "v1.0.5", latest: "v1.0.6", goos: "windows", withInstaller: true, wantOut: []string{"Skipped"}},
		{name: "windows --yes", current: "v1.0.5", latest: "v1.0.6", goos: "windows", withInstaller: true, assumeYes: true, wantInstall: true},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			srv := releaseServer(t, tt.latest, tt.withInstaller)
			var out bytes.Buffer
			var installedURL string
			err := runUpdate(context.Background(), updateOptions{
				current: tt.current, apiURL: srv.URL, goos: tt.goos,
				checkOnly: tt.checkOnly, assumeYes: tt.assumeYes,
				in: strings.NewReader(tt.stdin), out: &out,
				install: func(_ context.Context, url string, _ io.Writer) error {
					installedURL = url
					return nil
				},
			})
			if err != nil {
				t.Fatal(err)
			}
			for _, want := range tt.wantOut {
				if !strings.Contains(out.String(), want) {
					t.Errorf("output missing %q:\n%s", want, out.String())
				}
			}
			if (installedURL != "") != tt.wantInstall {
				t.Errorf("installer called = %v, want %v", installedURL != "", tt.wantInstall)
			}
			if tt.wantInstall && installedURL != "https://x/setup.exe" {
				t.Errorf("installer url = %q", installedURL)
			}
		})
	}
}

func TestRunUpdate_Errors(t *testing.T) {
	bad := httptest.NewServer(http.NotFoundHandler())
	defer bad.Close()
	if err := runUpdate(context.Background(), updateOptions{current: "v1.0.0", apiURL: bad.URL, out: io.Discard}); err == nil {
		t.Error("expected lookup error")
	}

	srv := releaseServer(t, "v1.0.6", true)
	want := errors.New("boom")
	err := runUpdate(context.Background(), updateOptions{
		current: "v1.0.5", apiURL: srv.URL, goos: "windows", assumeYes: true, out: io.Discard,
		install: func(context.Context, string, io.Writer) error { return want },
	})
	if !errors.Is(err, want) {
		t.Errorf("err = %v", err)
	}
}

func TestDownloadAndRunInstaller_BadStatus(t *testing.T) {
	srv := httptest.NewServer(http.NotFoundHandler())
	defer srv.Close()
	if err := downloadAndRunInstaller(context.Background(), srv.URL, io.Discard); err == nil {
		t.Error("expected error for non-200")
	}
	if err := downloadAndRunInstaller(context.Background(), "://bad", io.Discard); err == nil {
		t.Error("expected error for bad url")
	}
}