package tools

import (
	"context"
	"encoding/base64"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"regexp"
	"strconv"
	"strings"
	"testing"
	"time"

	"github.com/mark3labs/mcp-go/mcp"

	"spark-mcp-go/internal/audit"
	"spark-mcp-go/internal/cluster"
	"spark-mcp-go/internal/httpclient"
	"spark-mcp-go/internal/storage"
	"spark-mcp-go/internal/uploads"
)

// testDepsWithDataDir returns dependencies backed by an in-memory DB and a
// temporary data directory.
func testDepsWithDataDir(t *testing.T) (*Deps, *storage.ClusterRepo, *storage.SubmissionRepo, *audit.Repo) {
	t.Helper()
	db, err := storage.Open(":memory:")
	if err != nil {
		t.Fatalf("open db: %v", err)
	}
	t.Cleanup(func() { _ = db.Close() })

	dataDir := t.TempDir()
	uploadStore, err := uploads.New(filepath.Join(dataDir, "uploads"))
	if err != nil {
		t.Fatalf("new upload store: %v", err)
	}

	return &Deps{
		HTTPClient: httpclient.New(httpclient.Config{
			Timeout:          5 * time.Second,
			MaxResponseBytes: 1 << 20,
		}),
		AuditRepo:        audit.NewRepo(db),
		ClusterRepo:      db.Clusters(),
		SubmissionRepo:   db.Submissions(),
		MaxResponseBytes: 1 << 20,
		DataDir:          dataDir,
		UploadStore:      uploadStore,
	}, db.Clusters(), db.Submissions(), audit.NewRepo(db)
}

// createCluster creates a cluster in the repository with the given fields.
func createCluster(t *testing.T, repo *storage.ClusterRepo, c *cluster.Cluster) {
	t.Helper()
	if c.RMURL == "" {
		c.RMURL = "http://rm.example.com:8088"
	}
	if c.SHSURL == "" {
		c.SHSURL = "http://shs.example.com:18080"
	}
	if c.SparkSubmitExecuteBin == "" {
		c.SparkSubmitExecuteBin = "/usr/bin/spark-submit"
	}
	if err := repo.Create(context.Background(), c); err != nil {
		t.Fatalf("create cluster: %v", err)
	}
}

func resultText(t *testing.T, res *mcp.CallToolResult) string {
	t.Helper()
	if res.IsError {
		t.Fatalf("unexpected error result: %v", res.Content)
	}
	if len(res.Content) == 0 {
		t.Fatal("empty result content")
	}
	text, ok := mcp.AsTextContent(res.Content[0])
	if !ok {
		t.Fatalf("content is not text: %T", res.Content[0])
	}
	return text.Text
}

func resultJSON(t *testing.T, res *mcp.CallToolResult) map[string]any {
	t.Helper()
	var out map[string]any
	if err := json.Unmarshal([]byte(resultText(t, res)), &out); err != nil {
		t.Fatalf("unmarshal result: %v", err)
	}
	return out
}

func TestFetchURL(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"hello":"world"}`))
	}))
	defer srv.Close()

	deps, repo, _, _ := testDepsWithDataDir(t)
	createCluster(t, repo, &cluster.Cluster{
		ID:           "cluster-a",
		Name:         "Cluster A",
		IsActive:     true,
		AuthType:     cluster.AuthNone,
		URLAllowlist: []string{srv.URL},
	})

	t.Run("success", func(t *testing.T) {
		req := newToolRequest(FetchURLName, map[string]any{
			"cluster_id": "cluster-a",
			"url":        srv.URL + "/foo",
			"method":     "GET",
		})
		res, err := deps.FetchURLHandler(context.Background(), req)
		if err != nil {
			t.Fatalf("handler error: %v", err)
		}
		payload := resultJSON(t, res)
		if payload["status_code"] != float64(200) {
			t.Errorf("status_code=%v, want 200", payload["status_code"])
		}
		if !strings.Contains(payload["body"].(string), "hello") {
			t.Errorf("body missing hello: %v", payload["body"])
		}
	})

	t.Run("cluster not found", func(t *testing.T) {
		req := newToolRequest(FetchURLName, map[string]any{
			"cluster_id": "missing",
			"url":        srv.URL,
		})
		res, err := deps.FetchURLHandler(context.Background(), req)
		if err != nil {
			t.Fatalf("handler error: %v", err)
		}
		if !res.IsError {
			t.Errorf("expected error result, got: %v", res.Content)
		}
	})

	t.Run("private ip without allowlist", func(t *testing.T) {
		createCluster(t, repo, &cluster.Cluster{
			ID:       "cluster-private",
			Name:     "Private",
			IsActive: true,
			AuthType: cluster.AuthNone,
		})
		req := newToolRequest(FetchURLName, map[string]any{
			"cluster_id": "cluster-private",
			"url":        "http://127.0.0.1:12345/",
		})
		res, err := deps.FetchURLHandler(context.Background(), req)
		if err != nil {
			t.Fatalf("handler error: %v", err)
		}
		if !res.IsError {
			t.Errorf("expected error result, got: %v", res.Content)
		}
	})

	t.Run("public url without allowlist", func(t *testing.T) {
		createCluster(t, repo, &cluster.Cluster{
			ID:       "cluster-public",
			Name:     "Public",
			IsActive: true,
			AuthType: cluster.AuthNone,
		})
		req := newToolRequest(FetchURLName, map[string]any{
			"cluster_id": "cluster-public",
			"url":        "http://example.com/",
		})
		res, err := deps.FetchURLHandler(context.Background(), req)
		if err != nil {
			t.Fatalf("handler error: %v", err)
		}
		if !res.IsError {
			t.Errorf("expected error result, got: %v", res.Content)
		}
	})

	t.Run("invalid method", func(t *testing.T) {
		req := newToolRequest(FetchURLName, map[string]any{
			"cluster_id": "cluster-a",
			"url":        srv.URL,
			"method":     "INVALID",
		})
		res, err := deps.FetchURLHandler(context.Background(), req)
		if err != nil {
			t.Fatalf("handler error: %v", err)
		}
		if !res.IsError {
			t.Errorf("expected error result, got: %v", res.Content)
		}
	})

	t.Run("basic auth header sent", func(t *testing.T) {
		authSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			auth := r.Header.Get("Authorization")
			if auth == "" {
				http.Error(w, "missing auth", http.StatusUnauthorized)
				return
			}
			parts := strings.SplitN(auth, " ", 2)
			if len(parts) != 2 || parts[0] != "Basic" {
				http.Error(w, "bad auth", http.StatusUnauthorized)
				return
			}
			w.Write([]byte(parts[1]))
		}))
		defer authSrv.Close()

		createCluster(t, repo, &cluster.Cluster{
			ID:           "cluster-auth",
			Name:         "Auth",
			IsActive:     true,
			AuthType:     cluster.AuthBasic,
			AuthUsername: "u",
			AuthPassword: "p",
			URLAllowlist: []string{authSrv.URL},
		})

		req := newToolRequest(FetchURLName, map[string]any{
			"cluster_id": "cluster-auth",
			"url":        authSrv.URL,
		})
		res, err := deps.FetchURLHandler(context.Background(), req)
		if err != nil {
			t.Fatalf("handler error: %v", err)
		}
		payload := resultJSON(t, res)
		got := payload["body"].(string)
		want := base64.StdEncoding.EncodeToString([]byte("u:p"))
		if got != want {
			t.Errorf("auth body=%q, want %q", got, want)
		}
	})

	t.Run("user authorization header preserved", func(t *testing.T) {
		authSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			w.Write([]byte(r.Header.Get("Authorization")))
		}))
		defer authSrv.Close()

		createCluster(t, repo, &cluster.Cluster{
			ID:           "cluster-user-auth",
			Name:         "UserAuth",
			IsActive:     true,
			AuthType:     cluster.AuthBasic,
			AuthUsername: "u",
			AuthPassword: "p",
			URLAllowlist: []string{authSrv.URL},
		})

		req := newToolRequest(FetchURLName, map[string]any{
			"cluster_id": "cluster-user-auth",
			"url":        authSrv.URL,
			"headers": map[string]any{
				"Authorization": "Bearer user-token",
			},
		})
		res, err := deps.FetchURLHandler(context.Background(), req)
		if err != nil {
			t.Fatalf("handler error: %v", err)
		}
		payload := resultJSON(t, res)
		got := payload["body"].(string)
		if got != "Bearer user-token" {
			t.Errorf("authorization header=%q, want user token preserved", got)
		}
	})
}

func TestFetchURL_RedirectPreservesAuth(t *testing.T) {
	var server2URL string
	server2 := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		auth := r.Header.Get("Authorization")
		parts := strings.SplitN(auth, " ", 2)
		if len(parts) == 2 && parts[0] == "Basic" {
			w.Write([]byte(parts[1]))
			return
		}
		w.Write([]byte(auth))
	}))
	defer server2.Close()
	server2URL = server2.URL

	server1 := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Location", server2URL+"/final")
		w.WriteHeader(http.StatusTemporaryRedirect)
	}))
	defer server1.Close()

	deps, repo, _, _ := testDepsWithDataDir(t)
	createCluster(t, repo, &cluster.Cluster{
		ID:           "cluster-redirect",
		Name:         "Redirect",
		IsActive:     true,
		AuthType:     cluster.AuthBasic,
		AuthUsername: "u",
		AuthPassword: "p",
		URLAllowlist: []string{server1.URL, server2.URL},
	})

	req := newToolRequest(FetchURLName, map[string]any{
		"cluster_id": "cluster-redirect",
		"url":        server1.URL + "/start",
	})
	res, err := deps.FetchURLHandler(context.Background(), req)
	if err != nil {
		t.Fatalf("handler error: %v", err)
	}

	payload := resultJSON(t, res)
	got := payload["body"].(string)
	want := base64.StdEncoding.EncodeToString([]byte("u:p"))
	if got != want {
		t.Errorf("redirect auth body=%q, want %q", got, want)
	}
}

func TestUploadFile(t *testing.T) {
	deps, _, _, auditRepo := testDepsWithDataDir(t)

	req := newToolRequest(UploadFileName, map[string]any{
		"filename": "hello.txt",
		"content":  "hello world",
	})
	res, err := deps.UploadFileHandler(context.Background(), req)
	if err != nil {
		t.Fatalf("handler error: %v", err)
	}

	payload := resultJSON(t, res)
	fileID, ok := payload["file_id"].(string)
	if !ok || !regexp.MustCompile(`^[0-9a-f]{32}$`).MatchString(fileID) {
		t.Errorf("file_id=%v, want 32 lowercase hex chars", payload["file_id"])
	}
	path, ok := payload["path"].(string)
	if !ok || !filepath.IsAbs(path) || !strings.HasSuffix(path, "/"+fileID) {
		t.Errorf("path=%v, want absolute path ending in /%s", payload["path"], fileID)
	}
	if payload["name"] != "hello.txt" {
		t.Errorf("name=%v, want hello.txt", payload["name"])
	}
	if payload["size"] != float64(len("hello world")) {
		t.Errorf("size=%v, want %d", payload["size"], len("hello world"))
	}
	sha, ok := payload["sha256"].(string)
	if !ok || !regexp.MustCompile(`^[0-9a-f]{64}$`).MatchString(sha) {
		t.Errorf("sha256=%v, want 64-char hex", payload["sha256"])
	}

	got, err := os.ReadFile(path)
	if err != nil {
		t.Fatalf("read uploaded file: %v", err)
	}
	if string(got) != "hello world" {
		t.Errorf("content=%q, want %q", got, "hello world")
	}

	info, err := os.Stat(path)
	if err != nil {
		t.Fatalf("stat uploaded file: %v", err)
	}
	if info.Mode().Perm() != 0o640 {
		t.Errorf("mode=%o, want %o", info.Mode().Perm(), 0o640)
	}

	entries, err := auditRepo.List(context.Background(), 100)
	if err != nil {
		t.Fatalf("list audit: %v", err)
	}
	found := false
	for _, e := range entries {
		if e.Action == audit.ActionUploadCreate && e.Actor == "tool:upload_file" && e.ClusterID == fileID {
			found = true
			break
		}
	}
	if !found {
		t.Errorf("missing upload.create audit entry for file_id %s", fileID)
	}
}

func TestUploadFile_PathTraversal(t *testing.T) {
	deps, _, _, _ := testDepsWithDataDir(t)

	cases := []string{
		"../../../etc/passwd",
		"/etc/passwd",
		"foo/bar",
		"foo\\bar",
		"",
		"hello world",
		"中文.txt",
		"..",
	}

	for _, name := range cases {
		t.Run(strconv.Quote(name), func(t *testing.T) {
			req := newToolRequest(UploadFileName, map[string]any{
				"filename": name,
				"content":  "x",
			})
			res, err := deps.UploadFileHandler(context.Background(), req)
			if err != nil {
				t.Fatalf("handler error: %v", err)
			}
			if !res.IsError {
				t.Errorf("expected error for filename %q, got: %v", name, res.Content)
			}
		})
	}
}

func TestUploadFile_Base64(t *testing.T) {
	deps, _, _, _ := testDepsWithDataDir(t)

	req := newToolRequest(UploadFileName, map[string]any{
		"filename": "hello.bin",
		"content":  "aGVsbG8=",
		"encoding": "base64",
	})
	res, err := deps.UploadFileHandler(context.Background(), req)
	if err != nil {
		t.Fatalf("handler error: %v", err)
	}

	payload := resultJSON(t, res)
	path, ok := payload["path"].(string)
	if !ok || !filepath.IsAbs(path) {
		t.Errorf("path=%v, want absolute path", payload["path"])
	}
	if payload["name"] != "hello.bin" {
		t.Errorf("name=%v, want hello.bin", payload["name"])
	}
	if payload["size"] != float64(len("hello")) {
		t.Errorf("size=%v, want %d", payload["size"], len("hello"))
	}

	got, err := os.ReadFile(path)
	if err != nil {
		t.Fatalf("read uploaded file: %v", err)
	}
	if string(got) != "hello" {
		t.Errorf("content=%q, want %q", got, "hello")
	}
}