package main

import (
	"context"
	"io"
	"log/slog"
	"strings"
	"testing"
	"time"
)

func TestRunValidatesConfiguration(t *testing.T) {
	logger := slog.New(slog.NewJSONHandler(io.Discard, nil))
	t.Setenv("MOCK_PROVIDER_DUPLICATE_CALLBACKS", "invalid")
	if err := run(context.Background(), logger); err == nil || !strings.Contains(err.Error(), "duplicate callback") {
		t.Fatalf("duplicate validation error=%v", err)
	}
	t.Setenv("MOCK_PROVIDER_DUPLICATE_CALLBACKS", "2")
	t.Setenv("MOCK_PROVIDER_START_DELAY", "invalid")
	if err := run(context.Background(), logger); err == nil || !strings.Contains(err.Error(), "start delay") {
		t.Fatalf("delay validation error=%v", err)
	}
}

func TestRunStartsAndShutsDown(t *testing.T) {
	logger := slog.New(slog.NewJSONHandler(io.Discard, nil))
	t.Setenv("HTTP_ADDR", "127.0.0.1:0")
	t.Setenv("MOCK_PROVIDER_START_DELAY", "1ms")
	t.Setenv("MOCK_PROVIDER_DUPLICATE_CALLBACKS", "1")
	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
	defer cancel()
	if err := run(ctx, logger); err != nil {
		t.Fatalf("provider lifecycle: %v", err)
	}
}

func TestEnvUsesValueAndFallback(t *testing.T) {
	t.Setenv("MOCK_PROVIDER_TEST_VALUE", "configured")
	if got := env("MOCK_PROVIDER_TEST_VALUE", "fallback"); got != "configured" {
		t.Fatalf("value=%q", got)
	}
	if got := env("MOCK_PROVIDER_MISSING_VALUE", "fallback"); got != "fallback" {
		t.Fatalf("fallback=%q", got)
	}
}