package api

import (
	"bytes"
	"context"
	"encoding/json"
	"io"
	"mime/multipart"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"testing"

	"debtik/internal/auth"
	"debtik/internal/backup"
)

func TestBackupAPIHandlers(t *testing.T) {
	tempDir := t.TempDir()
	debtikDir := filepath.Join(tempDir, "debtik")
	netDir := filepath.Join(tempDir, "network")
	storeDir := filepath.Join(tempDir, "backups")

	_ = os.MkdirAll(debtikDir, 0755)
	_ = os.MkdirAll(netDir, 0755)

	_ = os.WriteFile(filepath.Join(debtikDir, "metadata.json"), []byte(`{"router": "test"}`), 0644)
	_ = os.WriteFile(filepath.Join(netDir, "interfaces.cfg"), []byte(`auto lo`), 0644)

	backupMgr := backup.NewManager(debtikDir, netDir, storeDir, nil)

	s := &Server{
		backupMgr: backupMgr,
		mux:       http.NewServeMux(),
		fsHandler: http.NotFoundHandler(),
	}
	s.registerRoutes()

	// 1. Test Backup Export (Download)
	req := httptest.NewRequest(http.MethodGet, "/api/system/backup/export?comment=APITest", nil)
	// Context with full admin role
	ctx := context.WithValue(req.Context(), sessionContextKey, &auth.Session{
		Username: "admin",
		Role:     auth.RoleFull,
	})
	req = req.WithContext(ctx)
	rec := httptest.NewRecorder()

	s.mux.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("Expected 200 OK from backup export, got %d: %s", rec.Code, rec.Body.String())
	}
	if rec.Header().Get("Content-Type") != "application/zip" {
		t.Errorf("Expected application/zip Content-Type, got %s", rec.Header().Get("Content-Type"))
	}
	zipBytes := rec.Body.Bytes()
	if len(zipBytes) == 0 {
		t.Fatal("Exported zip is empty")
	}

	// 2. Test Backup Inspect via multipart upload
	bodyBuf := new(bytes.Buffer)
	mpWriter := multipart.NewWriter(bodyBuf)
	part, err := mpWriter.CreateFormFile("backup", "test-backup.zip")
	if err != nil {
		t.Fatal(err)
	}
	_, _ = io.Copy(part, bytes.NewReader(zipBytes))
	_ = mpWriter.Close()

	inspectReq := httptest.NewRequest(http.MethodPost, "/api/system/backup/inspect", bodyBuf)
	inspectReq.Header.Set("Content-Type", mpWriter.FormDataContentType())
	inspectReq = inspectReq.WithContext(ctx)
	inspectRec := httptest.NewRecorder()

	s.mux.ServeHTTP(inspectRec, inspectReq)

	if inspectRec.Code != http.StatusOK {
		t.Fatalf("Expected 200 OK from backup inspect, got %d: %s", inspectRec.Code, inspectRec.Body.String())
	}

	var inspectResp struct {
		Success  bool             `json:"success"`
		Manifest *backup.Manifest `json:"manifest"`
	}
	if err := json.Unmarshal(inspectRec.Body.Bytes(), &inspectResp); err != nil {
		t.Fatalf("Failed unmarshaling inspect response: %v", err)
	}
	if !inspectResp.Success || inspectResp.Manifest == nil {
		t.Fatal("Expected success and manifest in inspect response")
	}
	if inspectResp.Manifest.Comment != "APITest" {
		t.Errorf("Manifest comment mismatch: %s != APITest", inspectResp.Manifest.Comment)
	}

	// 3. Test Backup Restore
	restoreBuf := new(bytes.Buffer)
	mpWriter2 := multipart.NewWriter(restoreBuf)
	part2, _ := mpWriter2.CreateFormFile("backup", "restore-backup.zip")
	_, _ = io.Copy(part2, bytes.NewReader(zipBytes))
	_ = mpWriter2.Close()

	restoreReq := httptest.NewRequest(http.MethodPost, "/api/system/backup/restore", restoreBuf)
	restoreReq.Header.Set("Content-Type", mpWriter2.FormDataContentType())
	restoreReq = restoreReq.WithContext(ctx)
	restoreRec := httptest.NewRecorder()

	s.mux.ServeHTTP(restoreRec, restoreReq)

	if restoreRec.Code != http.StatusOK {
		t.Fatalf("Expected 200 OK from backup restore, got %d: %s", restoreRec.Code, restoreRec.Body.String())
	}

	var restoreRes backup.RestoreResult
	if err := json.Unmarshal(restoreRec.Body.Bytes(), &restoreRes); err != nil {
		t.Fatalf("Failed unmarshaling restore response: %v", err)
	}
	if !restoreRes.Success {
		t.Error("Expected restore success true")
	}

	// 4. Test Backup List (should contain pre-restore safety backup)
	listReq := httptest.NewRequest(http.MethodGet, "/api/system/backups", nil)
	listReq = listReq.WithContext(ctx)
	listRec := httptest.NewRecorder()

	s.mux.ServeHTTP(listRec, listReq)

	if listRec.Code != http.StatusOK {
		t.Fatalf("Expected 200 OK from backup list, got %d: %s", listRec.Code, listRec.Body.String())
	}
	var backupsList []backup.BackupInfo
	if err := json.Unmarshal(listRec.Body.Bytes(), &backupsList); err != nil {
		t.Fatalf("Failed unmarshaling backup list: %v", err)
	}
	if len(backupsList) == 0 {
		t.Error("Expected at least 1 backup in list")
	}

	// 5. Test Forbidden for Read-Only user
	roCtx := context.WithValue(req.Context(), sessionContextKey, &auth.Session{
		Username: "readonly-user",
		Role:     auth.RoleRead,
	})
	roReq := httptest.NewRequest(http.MethodGet, "/api/system/backup/export", nil)
	roReq = roReq.WithContext(roCtx)
	roRec := httptest.NewRecorder()

	s.mux.ServeHTTP(roRec, roReq)

	if roRec.Code != http.StatusForbidden {
		t.Errorf("Expected 403 Forbidden for read-only user, got %d", roRec.Code)
	}
}