package app

import (
	"bufio"
	"context"
	"flag"
	"io"
	"os"
	"regexp"
	"testing"

	"github.com/rs/zerolog"

	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/config"
)

func TestMustSetupConfigAndLogging(t *testing.T) {
	// Configure app and logger
	type inputs struct {
		envs map[string]string
	}
	type outputs struct {
		appName        string
		logLevel       zerolog.Level
		logRegexChecks []*regexp.Regexp
	}
	tests := []struct {
		name   string
		inputs inputs
		want   outputs
	}{
		{
			name: "Test json logging with short timestamp",
			inputs: inputs{
				envs: map[string]string{
					"APP_NAME":            "testapp",
					"APP_LOG_LEVEL":       "warn",
					"APP_LOG_FORMAT":      "json",
					"APP_LOG_TIME_FORMAT": "short",
				},
			},
			want: outputs{
				appName:  "testapp",
				logLevel: zerolog.WarnLevel,
				logRegexChecks: []*regexp.Regexp{
					regexp.MustCompile(`^\{.*time":"\d{1,}:\d{2}`),
				},
			},
		},
		{
			name: "Test json logging with unix timestamp",
			inputs: inputs{
				envs: map[string]string{
					"APP_NAME":            "testapp",
					"APP_LOG_LEVEL":       "info",
					"APP_LOG_FORMAT":      "json",
					"APP_LOG_TIME_FORMAT": "unix",
				},
			},
			want: outputs{
				appName:  "testapp",
				logLevel: zerolog.InfoLevel,
				logRegexChecks: []*regexp.Regexp{
					regexp.MustCompile(`time":\d+,`),
				},
			},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Set environment variables
			for key, val := range tt.inputs.envs {
				os.Setenv(key, val)
			}

			// Prepare config in context
			ctx := MustSetupConfigAndLogging(context.Background())

			// Retrieve config and logger from prepared context
			cfg := config.MustFromCtx(ctx)
			logger := zerolog.Ctx(ctx)

			// Check wants
			if cfg.Name != tt.want.appName {
				t.Errorf("Expected app name %s, got %s", tt.want.appName, cfg.Name)
			}
			if logger.GetLevel() != tt.want.logLevel {
				t.Errorf("Expected log level %#v, got %#v", tt.want.logLevel, logger.GetLevel())
			}

			// Send and capture a log
			r, w := io.Pipe()
			testLogger := logger.Output(w)
			scanner := bufio.NewScanner(r)

			go func() {
				testLogger.Error().Msg("test message")
				w.Close()
			}()

			logOut := make([]byte, 0)
			if scanner.Scan() {
				logOut = scanner.Bytes()
			}

			// Check all expressions
			for _, expr := range tt.want.logRegexChecks {
				if !expr.Match(logOut) {
					t.Errorf("Regex %s did not match log %s", expr.String(), logOut)
				}
			}

			// Super annoying need to reset due to app framework package
			// using flag.Parse() and go test also using it
			testlog := flag.Lookup("test.testlogfile").Value.String()
			flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ExitOnError)
			flag.String("test.testlogfile", testlog, "")
			flag.String("test.paniconexit0", "", "")
			flag.String("test.v", "", "")
			flag.Parse()
		})
	}
}