package main

import (
	"context"
	"encoding/json"
	"fmt"
	"net"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"testing"
	"time"
)

func TestServerHealthViaSubprocess(t *testing.T) {
	dir := t.TempDir()
	port := freePort(t)
	cfgPath := writeServerConfig(t, dir, port)

	bin := buildServerBinary(t)

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	cmd := exec.CommandContext(ctx, bin, "-config", cfgPath)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	if err := cmd.Start(); err != nil {
		t.Fatalf("start server: %v", err)
	}
	t.Cleanup(func() {
		cancel()
		_ = cmd.Wait()
	})

	base := fmt.Sprintf("http://127.0.0.1:%d", port)
	waitForHealth(t, base+"/api/v1/health", 15*time.Second)

	resp, err := http.Get(base + "/api/v1/health")
	if err != nil {
		t.Fatalf("health GET: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		t.Fatalf("health status: got %d want 200", resp.StatusCode)
	}

	var body struct {
		Status  string `json:"status"`
		Service string `json:"service"`
		Version string `json:"version"`
	}
	if err := json.NewDecoder(resp.Body).Decode(&body); err != nil {
		t.Fatalf("decode health: %v", err)
	}
	if body.Status != "ok" {
		t.Fatalf("status: got %q want ok", body.Status)
	}
	if body.Service != "forge-mesh-server" {
		t.Fatalf("service: got %q", body.Service)
	}
	if body.Version == "" {
		t.Fatal("expected version in health response")
	}
}

func TestServerUsesConfigDataDirAndPort(t *testing.T) {
	dir := t.TempDir()
	port := freePort(t)
	cfgPath := writeServerConfig(t, dir, port)

	cfgData, err := os.ReadFile(cfgPath)
	if err != nil {
		t.Fatal(err)
	}
	if !containsAll(string(cfgData), dir, fmt.Sprintf("127.0.0.1:%d", port)) {
		t.Fatalf("config missing data_dir or listen_addr: %s", cfgData)
	}

	dbPath := filepath.Join(dir, "forge-mesh.db")
	artifacts := filepath.Join(dir, "artifacts")

	bin := buildServerBinary(t)
	ctx, cancel := context.WithTimeout(context.Background(), 12*time.Second)
	defer cancel()

	cmd := exec.CommandContext(ctx, bin, "-config", cfgPath)
	if err := cmd.Start(); err != nil {
		t.Fatalf("start: %v", err)
	}
	defer func() {
		cancel()
		_ = cmd.Wait()
	}()

	waitForHealth(t, fmt.Sprintf("http://127.0.0.1:%d/api/v1/health", port), 12*time.Second)

	for _, path := range []string{dbPath, artifacts, filepath.Join(dir, "signing.key")} {
		if _, err := os.Stat(path); err != nil {
			t.Fatalf("expected server to create %s: %v", path, err)
		}
	}
}

func buildServerBinary(t *testing.T) string {
	t.Helper()
	out := filepath.Join(t.TempDir(), "forge-mesh-server")
	cmd := exec.Command("go", "build", "-o", out, "./cmd/server")
	cmd.Dir = repoRoot(t)
	if outBytes, err := cmd.CombinedOutput(); err != nil {
		t.Fatalf("build server: %v\n%s", err, outBytes)
	}
	return out
}

func writeServerConfig(t *testing.T, dir string, port int) string {
	t.Helper()
	cfgPath := filepath.Join(dir, "config.json")
	content := fmt.Sprintf(`{
  "listen_addr": "127.0.0.1:%d",
  "data_dir": %q,
  "database_path": %q,
  "auth": {
    "basic_username": "admin",
    "basic_password": "changeme",
    "fleet_secret": "test-fleet-secret"
  },
  "forge": {
    "signing_key_path": %q,
    "artifacts_dir": %q
  }
}`, port, dir, filepath.Join(dir, "forge-mesh.db"),
		filepath.Join(dir, "signing.key"), filepath.Join(dir, "artifacts"))
	if err := os.WriteFile(cfgPath, []byte(content), 0o644); err != nil {
		t.Fatal(err)
	}
	return cfgPath
}

func freePort(t *testing.T) int {
	t.Helper()
	ln, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatal(err)
	}
	defer ln.Close()
	return ln.Addr().(*net.TCPAddr).Port
}

func waitForHealth(t *testing.T, url string, timeout time.Duration) {
	t.Helper()
	deadline := time.Now().Add(timeout)
	for time.Now().Before(deadline) {
		resp, err := http.Get(url)
		if err == nil {
			resp.Body.Close()
			if resp.StatusCode == http.StatusOK {
				return
			}
		}
		time.Sleep(200 * time.Millisecond)
	}
	t.Fatalf("server did not become healthy at %s within %s", url, timeout)
}

func repoRoot(t *testing.T) string {
	t.Helper()
	wd, err := os.Getwd()
	if err != nil {
		t.Fatal(err)
	}
	for {
		if _, err := os.Stat(filepath.Join(wd, "go.mod")); err == nil {
			return wd
		}
		parent := filepath.Dir(wd)
		if parent == wd {
			t.Fatal("go.mod not found")
		}
		wd = parent
	}
}

func containsAll(s string, parts ...string) bool {
	for _, p := range parts {
		if !contains(s, p) {
			return false
		}
	}
	return true
}

func contains(s, sub string) bool {
	return len(sub) == 0 || (len(s) >= len(sub) && indexOf(s, sub) >= 0)
}

func indexOf(s, sub string) int {
	for i := 0; i+len(sub) <= len(s); i++ {
		if s[i:i+len(sub)] == sub {
			return i
		}
	}
	return -1
}