package api

import (
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestAgentBinaryCandidates(t *testing.T) {
	dir := "/srv/usb"
	cases := []struct {
		platform string
		wantName string
		wantPath string
	}{
		{"windows", "crypto-miner-agent.exe", filepath.Join(dir, "agent", "crypto-miner-agent.exe")},
		{"mac", "crypto-miner-agent", filepath.Join(dir, "agent", "crypto-miner-agent-darwin")},
		{"linux", "crypto-miner-agent", filepath.Join(dir, "agent", "crypto-miner-agent-linux")},
	}
	for _, tc := range cases {
		candidates, dlName := agentBinaryCandidates(tc.platform, dir)
		if dlName != tc.wantName {
			t.Fatalf("platform=%s dlName=%q want %q", tc.platform, dlName, tc.wantName)
		}
		if len(candidates) == 0 || candidates[0] != tc.wantPath {
			t.Fatalf("platform=%s candidates=%v want first %q", tc.platform, candidates, tc.wantPath)
		}
	}
}

func TestFindAgentBinaryPrefersAgentSubdir(t *testing.T) {
	root := t.TempDir()
	agentDir := filepath.Join(root, "agent")
	if err := os.MkdirAll(agentDir, 0755); err != nil {
		t.Fatal(err)
	}
	nested := filepath.Join(agentDir, "crypto-miner-agent.exe")
	rootLevel := filepath.Join(root, "crypto-miner-agent.exe")
	if err := os.WriteFile(nested, []byte("nested-agent"), 0644); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(rootLevel, []byte("root-agent"), 0644); err != nil {
		t.Fatal(err)
	}
	got, dlName, ok := findAgentBinary("windows", root)
	if !ok || got != nested {
		t.Fatalf("findAgentBinary = %q ok=%v want nested %q", got, ok, nested)
	}
	if dlName != "crypto-miner-agent.exe" {
		t.Fatalf("dlName=%q", dlName)
	}
}

func TestFindAgentBinaryFallbackRootLevel(t *testing.T) {
	root := t.TempDir()
	bin := filepath.Join(root, "crypto-miner-agent-linux")
	if err := os.WriteFile(bin, []byte("linux-agent"), 0644); err != nil {
		t.Fatal(err)
	}
	got, dlName, ok := findAgentBinary("linux", root)
	if !ok || got != bin {
		t.Fatalf("findAgentBinary = %q ok=%v", got, ok)
	}
	if dlName != "crypto-miner-agent" {
		t.Fatalf("dlName=%q", dlName)
	}
}

func TestFindAgentBinaryMacGenericFallback(t *testing.T) {
	root := t.TempDir()
	agentDir := filepath.Join(root, "agent")
	if err := os.MkdirAll(agentDir, 0755); err != nil {
		t.Fatal(err)
	}
	bin := filepath.Join(agentDir, "crypto-miner-agent")
	if err := os.WriteFile(bin, []byte("generic-unix-agent"), 0644); err != nil {
		t.Fatal(err)
	}
	got, _, ok := findAgentBinary("mac", root)
	if !ok || got != bin {
		t.Fatalf("findAgentBinary = %q ok=%v", got, ok)
	}
}

func TestFindAgentBinaryMissing(t *testing.T) {
	_, _, ok := findAgentBinary("mac", t.TempDir())
	if ok {
		t.Fatal("expected missing binary")
	}
}

func withAgentBinarySearchDir(t *testing.T, root string) {
	t.Helper()
	orig := agentBinarySearchDir
	agentBinarySearchDir = func() (string, error) { return root, nil }
	t.Cleanup(func() { agentBinarySearchDir = orig })
}

func TestServeAgentBinaryDownloadWindows(t *testing.T) {
	root := t.TempDir()
	bin := filepath.Join(root, "agent", "crypto-miner-agent.exe")
	if err := os.MkdirAll(filepath.Dir(bin), 0755); err != nil {
		t.Fatal(err)
	}
	content := []byte("MZ-fake-windows-agent")
	if err := os.WriteFile(bin, content, 0644); err != nil {
		t.Fatal(err)
	}
	withAgentBinarySearchDir(t, root)

	req := httptest.NewRequest(http.MethodGet, "/api/download/agent-windows", nil)
	rec := httptest.NewRecorder()
	serveAgentBinary("windows")(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("status=%d body=%s", rec.Code, rec.Body.String())
	}
	if rec.Body.String() != string(content) {
		t.Fatalf("body=%q", rec.Body.String())
	}
	if !strings.Contains(rec.Header().Get("Content-Disposition"), "crypto-miner-agent.exe") {
		t.Fatalf("disposition=%q", rec.Header().Get("Content-Disposition"))
	}
}

func TestServeAgentBinaryDownloadMac(t *testing.T) {
	root := t.TempDir()
	bin := filepath.Join(root, "crypto-miner-agent-darwin")
	if err := os.WriteFile(bin, []byte("darwin-agent"), 0644); err != nil {
		t.Fatal(err)
	}
	withAgentBinarySearchDir(t, root)

	req := httptest.NewRequest(http.MethodGet, "/api/download/agent-mac", nil)
	rec := httptest.NewRecorder()
	serveAgentBinary("mac")(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("status=%d", rec.Code)
	}
	if !strings.Contains(rec.Header().Get("Content-Disposition"), "crypto-miner-agent") {
		t.Fatalf("disposition=%q", rec.Header().Get("Content-Disposition"))
	}
}

func TestServeAgentBinaryNotFound(t *testing.T) {
	withAgentBinarySearchDir(t, t.TempDir())

	req := httptest.NewRequest(http.MethodGet, "/api/download/agent-linux", nil)
	rec := httptest.NewRecorder()
	serveAgentBinary("linux")(rec, req)
	if rec.Code != http.StatusNotFound {
		t.Fatalf("status=%d want 404", rec.Code)
	}
}