package server

import (
	"bytes"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"gitea.hsrv.site/mrleo1nid/backup-master/internal/manifest"
)

func newTestServer(t *testing.T) (*Server, *httptest.Server) {
	t.Helper()
	s, err := New(Config{DataDir: t.TempDir(), PublicURL: "https://backup.test"})
	if err != nil {
		t.Fatal(err)
	}
	ts := httptest.NewServer(s.Handler())
	t.Cleanup(func() { ts.Close(); s.Close() })
	return s, ts
}

func call(t *testing.T, method, url, token string, body io.Reader) *http.Response {
	t.Helper()
	req, err := http.NewRequest(method, url, body)
	if err != nil {
		t.Fatal(err)
	}
	if token != "" {
		req.Header.Set("Authorization", "Bearer "+token)
	}
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { resp.Body.Close() })
	return resp
}

func decode(t *testing.T, resp *http.Response, v any) {
	t.Helper()
	if err := json.NewDecoder(resp.Body).Decode(v); err != nil {
		t.Fatal(err)
	}
}

func sum(b []byte) string {
	h := sha256.Sum256(b)
	return hex.EncodeToString(h[:])
}

func TestUploadAndRestoreFlow(t *testing.T) {
	s, ts := newTestServer(t)
	agentTok := newToken()
	clientID, err := s.st.CreateClient("nl1", "nl1.example.com", hashToken(agentTok))
	if err != nil {
		t.Fatal(err)
	}

	// без токена — 401
	if r := call(t, "GET", ts.URL+"/api/v1/agent/config", "", nil); r.StatusCode != 401 {
		t.Fatalf("без токена: %d", r.StatusCode)
	}
	var cfg AgentConfigResponse
	r := call(t, "GET", ts.URL+"/api/v1/agent/config", agentTok, nil)
	decode(t, r, &cfg)
	if cfg.Domain != "nl1.example.com" || !cfg.HeavyDue {
		t.Fatalf("config: %+v", cfg)
	}

	m := manifest.Manifest{FormatVersion: 1, Hostname: "nl1", Parts: []string{"main", "stoat"}}
	raw, _ := json.Marshal(m)
	r = call(t, "POST", ts.URL+"/api/v1/backups", agentTok, bytes.NewReader(raw))
	if r.StatusCode != 201 {
		t.Fatalf("create: %d", r.StatusCode)
	}
	var created struct{ ID int64 }
	decode(t, r, &created)

	mainData := []byte("main-archive-data")
	heavyData := bytes.Repeat([]byte("minio"), 1000)
	for name, data := range map[string][]byte{"main": mainData, "stoat": heavyData} {
		r = call(t, "PUT", fmt.Sprintf("%s/api/v1/backups/%d/parts/%s", ts.URL, created.ID, name), agentTok, bytes.NewReader(data))
		if r.StatusCode != 200 {
			t.Fatalf("upload %s: %d", name, r.StatusCode)
		}
	}
	// часть вне манифеста
	r = call(t, "PUT", fmt.Sprintf("%s/api/v1/backups/%d/parts/other", ts.URL, created.ID), agentTok, strings.NewReader("x"))
	if r.StatusCode != 400 {
		t.Fatalf("чужая часть: %d", r.StatusCode)
	}

	done := CompleteRequest{Parts: []PartInfo{
		{Name: "main", Size: int64(len(mainData)), SHA256: sum(mainData)},
		{Name: "stoat", Size: int64(len(heavyData)), SHA256: sum(heavyData)},
	}}
	raw, _ = json.Marshal(done)
	r = call(t, "POST", fmt.Sprintf("%s/api/v1/backups/%d/complete", ts.URL, created.ID), agentTok, bytes.NewReader(raw))
	if r.StatusCode != 200 {
		body, _ := io.ReadAll(r.Body)
		t.Fatalf("complete: %d %s", r.StatusCode, body)
	}

	c, _ := s.st.GetClient(clientID)
	if c.LastBackupAt == 0 || c.LastHeavyAt == 0 {
		t.Fatalf("клиент не отмечен: %+v", c)
	}
	r = call(t, "GET", ts.URL+"/api/v1/agent/config", agentTok, nil)
	decode(t, r, &cfg)
	if cfg.HeavyDue {
		t.Fatal("heavy только что загружен")
	}

	// upload-токен не даёт читать
	if r := call(t, "GET", ts.URL+"/api/v1/restore/manifest", agentTok, nil); r.StatusCode != 401 {
		t.Fatalf("агентский токен читает бэкапы: %d", r.StatusCode)
	}

	restoreTok := newToken()
	if err := s.st.CreateRestoreToken(hashToken(restoreTok), clientID, time.Hour); err != nil {
		t.Fatal(err)
	}
	var rm RestoreManifestResponse
	r = call(t, "GET", ts.URL+"/api/v1/restore/manifest", restoreTok, nil)
	decode(t, r, &rm)
	if rm.BackupID != created.ID || len(rm.Parts) != 2 {
		t.Fatalf("restore manifest: %+v", rm)
	}
	var got manifest.Manifest
	if err := json.Unmarshal(rm.Manifest, &got); err != nil || got.Domain != "nl1.example.com" {
		t.Fatalf("manifest domain: %q %v", got.Domain, err)
	}

	// скачивание с Range (докачка)
	req, _ := http.NewRequest("GET", fmt.Sprintf("%s/api/v1/restore/%d/parts/main", ts.URL, created.ID), nil)
	req.Header.Set("Authorization", "Bearer "+restoreTok)
	req.Header.Set("Range", "bytes=5-")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	body, _ := io.ReadAll(resp.Body)
	resp.Body.Close()
	if resp.StatusCode != 206 || string(body) != string(mainData[5:]) {
		t.Fatalf("range: %d %q", resp.StatusCode, body)
	}
}

func TestChecksumMismatchFails(t *testing.T) {
	s, ts := newTestServer(t)
	tok := newToken()
	if _, err := s.st.CreateClient("x", "x.example.com", hashToken(tok)); err != nil {
		t.Fatal(err)
	}
	raw, _ := json.Marshal(manifest.Manifest{Parts: []string{"main"}})
	r := call(t, "POST", ts.URL+"/api/v1/backups", tok, bytes.NewReader(raw))
	var created struct{ ID int64 }
	decode(t, r, &created)
	call(t, "PUT", fmt.Sprintf("%s/api/v1/backups/%d/parts/main", ts.URL, created.ID), tok, strings.NewReader("data"))
	raw, _ = json.Marshal(CompleteRequest{Parts: []PartInfo{{Name: "main", Size: 4, SHA256: "bad"}}})
	r = call(t, "POST", fmt.Sprintf("%s/api/v1/backups/%d/complete", ts.URL, created.ID), tok, bytes.NewReader(raw))
	if r.StatusCode != 400 {
		t.Fatalf("complete с неверной суммой: %d", r.StatusCode)
	}
	b, _ := s.st.GetBackup(created.ID)
	if b.Status != StatusFailed {
		t.Fatalf("статус %s", b.Status)
	}
}

func TestWebLoginAndPages(t *testing.T) {
	s, ts := newTestServer(t)
	if err := s.st.SetAdmin("admin", "secret-pass"); err != nil {
		t.Fatal(err)
	}
	client := &http.Client{CheckRedirect: func(*http.Request, []*http.Request) error { return http.ErrUseLastResponse }}
	resp, err := client.Get(ts.URL + "/")
	if err != nil {
		t.Fatal(err)
	}
	resp.Body.Close()
	if resp.StatusCode != 303 {
		t.Fatalf("без сессии: %d", resp.StatusCode)
	}
	resp, err = client.PostForm(ts.URL+"/login", map[string][]string{"user": {"admin"}, "password": {"secret-pass"}})
	if err != nil {
		t.Fatal(err)
	}
	resp.Body.Close()
	var session *http.Cookie
	for _, c := range resp.Cookies() {
		if c.Name == sessionCookie {
			session = c
		}
	}
	if session == nil {
		t.Fatal("нет cookie сессии")
	}
	for _, p := range []string{"/", "/clients/new", "/settings"} {
		req, _ := http.NewRequest("GET", ts.URL+p, nil)
		req.AddCookie(session)
		resp, err := client.Do(req)
		if err != nil {
			t.Fatal(err)
		}
		resp.Body.Close()
		if resp.StatusCode != 200 {
			t.Fatalf("%s: %d", p, resp.StatusCode)
		}
	}
	// POST без CSRF отклоняется
	req, _ := http.NewRequest("POST", ts.URL+"/clients", strings.NewReader("domain=a.example.com"))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.AddCookie(session)
	resp, err = client.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	resp.Body.Close()
	if resp.StatusCode != 403 {
		t.Fatalf("без CSRF: %d", resp.StatusCode)
	}
}