package web

import (
	"bytes"
	"encoding/json"
	"log"
	"net/http"
	"net/http/httptest"
	"net/url"
	"strings"
	"sync/atomic"
	"testing"
)

// R-138 option C (operator ruling 2026-10-08, `09` §3 decision 190): a pasted Cloudflare API token is saved only when
// Cloudflare says it sees exactly this customer's own zone. A fake Cloudflare (httptest) stands in for the API; no
// real call is made. The CONSEQUENCE asserted is the stored config: a refused token is not stored, and on edit the
// previous token stays.
//
// RED-PROOF: remove the cfTokenReachMessage block from handleConfigCreate → TestR138_CreateRefusesWideToken stores
// customer „b" with the account-wide token → FAILS.

const (
	tokOwn   = "tok-own-zone-0123456789abcdef"
	tokWide  = "tok-account-wide-0123456789abcdef"
	tokOther = "tok-other-zone-0123456789abcdef"
	tokNone  = "tok-sees-nothing-0123456789abcdef"
	tokOwn2  = "tok-own-zone-second-0123456789abcdef"
)

type fakeCF struct {
	srv   *httptest.Server
	calls atomic.Int32
	down  atomic.Bool
}

func newFakeCF(t *testing.T) *fakeCF {
	f := &fakeCF{}
	f.srv = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		f.calls.Add(1)
		if f.down.Load() {
			http.Error(w, `{"success":false}`, http.StatusServiceUnavailable)
			return
		}
		if r.URL.Path != "/zones" {
			http.NotFound(w, r)
			return
		}
		var zones []string
		switch strings.TrimPrefix(r.Header.Get("Authorization"), "Bearer ") {
		case tokOwn, tokOwn2:
			zones = []string{"example.hu"}
		case tokWide:
			zones = []string{"example.hu", "neighbour.hu"}
		case tokOther:
			zones = []string{"neighbour.hu"}
		case tokNone:
			zones = nil
		default:
			w.WriteHeader(http.StatusForbidden)
			w.Write([]byte(`{"success":false,"errors":[{"message":"Invalid API Token"}]}`))
			return
		}
		res := []map[string]string{}
		for i, z := range zones {
			res = append(res, map[string]string{"id": "z" + string(rune('0'+i)), "name": z})
		}
		json.NewEncoder(w).Encode(map[string]interface{}{"success": true, "result": res, "result_info": map[string]int{"total_count": len(res)}})
	}))
	t.Cleanup(f.srv.Close)
	return f
}

func r138Server(t *testing.T) (*Server, *fakeCF, *bytes.Buffer) {
	s, _ := newTestServer(t)
	f := newFakeCF(t)
	s.cfAPIBase = f.srv.URL
	var logs bytes.Buffer
	s.logger = log.New(&logs, "", 0)
	return s, f, &logs
}

func r138Create(s *Server, id, domain, token string) *httptest.ResponseRecorder {
	form := url.Values{"customer_id": {id}, "customer_name": {"T " + id}, "email": {"t@example.org"}, "domain": {domain}, "cf_api_token": {token}}
	req := httptest.NewRequest(http.MethodPost, "/configs/new", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rr := httptest.NewRecorder()
	s.handleConfigCreate(rr, req)
	return rr
}

func r138Edit(s *Server, id, domain, token string) *httptest.ResponseRecorder {
	form := url.Values{"customer_name": {"T " + id}, "email": {"t@example.org"}, "domain": {domain}, "cf_api_token": {token}}
	req := httptest.NewRequest(http.MethodPost, "/configs/"+id, strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rr := httptest.NewRecorder()
	s.handleConfigUpdate(rr, req, id)
	return rr
}

func r138StoredToken(t *testing.T, s *Server, id string) (string, bool) {
	t.Helper()
	cfg, _ := s.store.GetCustomerConfig(id)
	if cfg == nil {
		return "", false
	}
	return storedCFToken(cfg.ConfigJSON), true
}

func TestR138_CreateAcceptsOwnZoneToken(t *testing.T) {
	s, f, _ := r138Server(t)
	if rr := r138Create(s, "a", "example.hu", tokOwn); rr.Code != http.StatusSeeOther {
		t.Fatalf("own-zone token must be accepted; got %d %s", rr.Code, rr.Body.String())
	}
	if tok, ok := r138StoredToken(t, s, "a"); !ok || tok != tokOwn {
		t.Fatalf("the own-zone token was not stored (stored=%v)", ok)
	}
	if f.calls.Load() != 1 {
		t.Errorf("expected exactly 1 Cloudflare call, got %d", f.calls.Load())
	}
	// A domain UNDER the token's one zone is the customer's own too (the zone is the customer's, `01` §7).
	s2, _, _ := r138Server(t)
	if rr := r138Create(s2, "sub", "home.example.hu", tokOwn); rr.Code != http.StatusSeeOther {
		t.Errorf("a domain under the token's one zone must be accepted; got %d %s", rr.Code, rr.Body.String())
	}
}

func TestR138_CreateRefusesWideToken(t *testing.T) {
	s, _, _ := r138Server(t)
	cases := []struct{ id, tok, want string }{
		{"b", tokWide, "reaches 2 zones"},
		{"c", tokOther, "neighbour.hu"},
		{"d", tokNone, "sees no zone"},
		{"e", "tok-rejected-by-cloudflare-0123456789", "could not be asked"},
	}
	for _, c := range cases {
		rr := r138Create(s, c.id, "example.hu", c.tok)
		if rr.Code == http.StatusSeeOther {
			t.Errorf("%s: token was accepted — it must be refused", c.id)
		}
		if !strings.Contains(rr.Body.String(), c.want) {
			t.Errorf("%s: the refusal must say %q; got %d", c.id, c.want, rr.Code)
		}
		if _, ok := r138StoredToken(t, s, c.id); ok {
			t.Errorf("%s: a config was stored for a refused token", c.id)
		}
	}
}

func TestR138_EditRefusedTokenKeepsOldToken(t *testing.T) {
	s, f, _ := r138Server(t)
	if rr := r138Create(s, "a", "example.hu", tokOwn); rr.Code != http.StatusSeeOther {
		t.Fatalf("create: %d", rr.Code)
	}
	// A wide token on edit: refused, old token stays.
	if rr := r138Edit(s, "a", "example.hu", tokWide); !strings.Contains(rr.Body.String(), "Nothing was saved") {
		t.Errorf("wide token on edit must be refused; got %d", rr.Code)
	}
	if tok, _ := r138StoredToken(t, s, "a"); tok != tokOwn {
		t.Errorf("after a refused edit the previous token must stay")
	}
	// Cloudflare down: refused, old token stays.
	f.down.Store(true)
	if rr := r138Edit(s, "a", "example.hu", tokOwn2); !strings.Contains(rr.Body.String(), "previous token stays") {
		t.Errorf("Cloudflare down must refuse with the clear sentence; got %d", rr.Code)
	}
	if tok, _ := r138StoredToken(t, s, "a"); tok != tokOwn {
		t.Errorf("while Cloudflare is down the previous token must stay")
	}
	// Unreachable (server closed): refused too.
	f.down.Store(false)
	f.srv.Close()
	if rr := r138Edit(s, "a", "example.hu", tokOwn2); !strings.Contains(rr.Body.String(), "previous token stays") {
		t.Errorf("unreachable Cloudflare must refuse; got %d", rr.Code)
	}
	if tok, _ := r138StoredToken(t, s, "a"); tok != tokOwn {
		t.Errorf("while Cloudflare is unreachable the previous token must stay")
	}
}

func TestR138_UnchangedOrEmptyTokenMakesNoCall(t *testing.T) {
	s, f, _ := r138Server(t)
	if rr := r138Create(s, "a", "example.hu", tokOwn); rr.Code != http.StatusSeeOther {
		t.Fatalf("create: %d", rr.Code)
	}
	before := f.calls.Load()
	f.down.Store(true) // any call would now refuse — so a successful save proves no call was needed
	if rr := r138Edit(s, "a", "example.hu", tokOwn); strings.Contains(rr.Body.String(), "Nothing was saved") || strings.Contains(rr.Body.String(), "previous token stays") {
		t.Errorf("an unchanged token on an unchanged domain must not be checked; got %s", rr.Body.String())
	}
	if f.calls.Load() != before {
		t.Errorf("unchanged token made %d Cloudflare call(s)", f.calls.Load()-before)
	}
	// Empty token (HTTP-01): no call, on create and on edit.
	if rr := r138Create(s, "h", "http01.hu", ""); rr.Code != http.StatusSeeOther {
		t.Errorf("empty token create must be accepted; got %d", rr.Code)
	}
	if rr := r138Edit(s, "a", "example.hu", ""); strings.Contains(rr.Body.String(), "previous token stays") {
		t.Errorf("clearing the token must not be checked")
	}
	if f.calls.Load() != before {
		t.Errorf("empty token made %d Cloudflare call(s)", f.calls.Load()-before)
	}
}

func TestR138_TokenNeverInLogsOrPage(t *testing.T) {
	s, f, logs := r138Server(t)
	var pages strings.Builder
	for _, tok := range []string{tokOwn, tokWide, tokOther, tokNone} {
		rr := r138Create(s, "x"+tok[4:8], "example.hu", tok)
		if rr.Code != http.StatusSeeOther {
			pages.WriteString(rr.Body.String())
		}
	}
	f.down.Store(true)
	pages.WriteString(r138Create(s, "y", "example.hu", tokOwn2).Body.String())
	for _, tok := range []string{tokOwn, tokWide, tokOther, tokNone, tokOwn2} {
		if strings.Contains(logs.String(), tok) {
			t.Errorf("a token appeared in the log")
		}
	}
	if !strings.Contains(logs.String(), "cloudflare token check") {
		t.Errorf("positive control: the check must log its outcome; log was %q", logs.String())
	}
	// The form echoes what the operator typed (as it always has), but the refusal SENTENCE never carries the token.
	for _, line := range strings.Split(pages.String(), "\n") {
		if strings.Contains(line, "Nothing was saved") || strings.Contains(line, "previous token stays") {
			for _, tok := range []string{tokWide, tokOther, tokNone, tokOwn2} {
				if strings.Contains(line, tok) {
					t.Errorf("a refusal sentence carried the token")
				}
			}
		}
	}
}