package api

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"testing"
	"time"

	"gitea.dooplex.hu/admin/felhom-controller/internal/backup"
	"gitea.dooplex.hu/admin/felhom-controller/internal/config"
	"gitea.dooplex.hu/admin/felhom-controller/internal/settings"
	"gitea.dooplex.hu/admin/felhom-controller/internal/stacks"
)

// Update arc slice 4 through the PRODUCTION handler: actionStack → the real stacks.Manager
// (NewManager + ScanStacks) and the real backup.Manager over real settings. No docker is reached:
// every path here refuses, or fails at the pin (the app's catalog template is absent on purpose).

type apiFakeGuards struct {
	b            *backup.Manager
	points       []stacks.UpdateRestorePoint
	cannotBackUp bool
	// blindToHolds makes the manager-side preflight NOT see holds, so a test can prove the ROUTER's
	// own hold check refuses — the two layers are each pinned separately (the preflight's by
	// TestSlice4_D_CheapRefusals/held). Without it, removing either layer passes inertly, because the
	// other refuses with the same sentence (observed on the first run of red-proof 4, 2026-09-13).
	blindToHolds bool
}

func (g *apiFakeGuards) HoldFor(n string) (bool, string) {
	if g.blindToHolds {
		return false, ""
	}
	return g.b.RestoreHoldFor(n)
}
func (g *apiFakeGuards) Busy(string) (bool, string) { return false, "" }
func (g *apiFakeGuards) RestorePoints(_ context.Context, _ string, accept func(stacks.UpdateRestorePoint) bool) (stacks.UpdateRestorePoint, bool, []stacks.UpdateRestorePoint) {
	for _, p := range g.points {
		if accept == nil || accept(p) {
			return p, true, g.points
		}
	}
	return stacks.UpdateRestorePoint{}, false, g.points
}
func (g *apiFakeGuards) CanBackUp(string) (bool, string)         { return !g.cannotBackUp, "fake: no drive" }
func (g *apiFakeGuards) BackupNow(context.Context, string) error { return nil }
func (g *apiFakeGuards) SafetyDump(context.Context, string) ([]string, error) {
	return nil, nil
}
func (g *apiFakeGuards) HoldAfterFailedUpdate(string, time.Time, stacks.UpdateRestorePoint, string) error {
	return nil
}

const slice4AppYAML = "deployed: true\nenv: {}\npinned_images:\n    app: nginx:1.27\n"

func newSlice4Router(t *testing.T) (*Router, *settings.Settings, *apiFakeGuards, string) {
	t.Helper()
	root := t.TempDir()
	dir := filepath.Join(root, "stacks", "app")
	if err := os.MkdirAll(dir, 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(dir, "docker-compose.yml"), []byte("services:\n  app:\n    image: nginx:1.27\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(dir, "app.yaml"), []byte(slice4AppYAML), 0o600); err != nil {
		t.Fatal(err)
	}
	cfg := &config.Config{}
	cfg.Paths.StacksDir = filepath.Join(root, "stacks")
	cfg.Paths.DataDir = filepath.Join(root, "data")
	cfg.Paths.SystemDataPath = filepath.Join(root, "sys")
	cfg.Stacks.ComposeCommand = "docker compose"
	lg := log.New(io.Discard, "", 0)
	m, err := stacks.NewManager(cfg, lg)
	if err != nil {
		t.Fatal(err)
	}
	if err := m.ScanStacks(); err != nil {
		t.Fatal(err)
	}
	sett, err := settings.Load(filepath.Join(root, "settings.json"), lg)
	if err != nil {
		t.Fatal(err)
	}
	b := backup.NewManager(cfg, sett, lg)
	g := &apiFakeGuards{b: b, points: []stacks.UpdateRestorePoint{{Tier: stacks.UpdateTierSecondDrive, ProvenAt: time.Now().Add(-time.Hour)}}}
	m.SetUpdateGuards(g)
	return &Router{cfg: cfg, stackMgr: m, backupMgr: b, logger: lg}, sett, g, dir
}

func postUpdate(t *testing.T, r *Router) (int, apiResponse) {
	t.Helper()
	w := httptest.NewRecorder()
	r.actionStack(w, httptest.NewRequest("POST", "/api/stacks/x/action", nil), "update", "app")
	var resp apiResponse
	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
		t.Fatalf("non-JSON body %q: %v", w.Body.String(), err)
	}
	return w.Code, resp
}

// TestR439_UpdateOfAHeldAppIsRefused — R-439 closed.
//
// COMPANION RED-PROOF 4 (REPORT.md): remove `|| action == "update"` from actionStack's hold check. The
// preflight then refuses on its own grounds with a DIFFERENT sentence, and this test fails on the
// message — which is what proves the router line is the one doing it.
func TestR439_UpdateOfAHeldAppIsRefused(t *testing.T) {
	r, sett, g, dir := newSlice4Router(t)
	g.points, g.cannotBackUp = nil, true // the preflight's own refusal would say "no backup" — not the hold
	g.blindToHolds = true                // only the router's line can produce the hold's sentence
	if err := sett.SetRestoreHold(settings.RestoreHold{Stack: "app", At: "2026-09-13T08:00:00Z", Reason: settings.HoldReasonUpdateFailed, CopyDate: "2026-09-13T01:30:00Z"}); err != nil {
		t.Fatal(err)
	}
	before, _ := os.ReadFile(filepath.Join(dir, "app.yaml"))
	code, resp := postUpdate(t, r)
	_, holdText := r.backupMgr.RestoreHoldFor("app")
	if code != http.StatusConflict || resp.OK || resp.Error != holdText {
		t.Fatalf("a HELD app's update must be refused with the hold's own sentence: code=%d ok=%v error=%q", code, resp.OK, resp.Error)
	}
	after, _ := os.ReadFile(filepath.Join(dir, "app.yaml"))
	if string(before) != string(after) {
		t.Error("a refused update must record no intent — app.yaml changed")
	}
}

func TestSlice4_Router_NoBackupIs409AndRecordsNothing(t *testing.T) {
	r, _, g, dir := newSlice4Router(t)
	g.points, g.cannotBackUp = nil, true
	before, _ := os.ReadFile(filepath.Join(dir, "app.yaml"))
	code, resp := postUpdate(t, r)
	if code != http.StatusConflict || resp.Error != fmt.Sprintf(stacks.MsgUpdateNoBackupFmt, "app") {
		t.Fatalf("code=%d error=%q", code, resp.Error)
	}
	if after, _ := os.ReadFile(filepath.Join(dir, "app.yaml")); string(before) != string(after) {
		t.Error("the preflight refusal must come BEFORE the intent write")
	}
}

// TestR443_UpdateIsNeverReportedCompleteSynchronously — R-443 closed. The handler answers 202 with
// completed:false; the job then runs (and here fails at the pin, the catalog being absent), and the
// outcome exists ONLY on GET /api/stacks/{name}.
func TestR443_UpdateIsNeverReportedCompleteSynchronously(t *testing.T) {
	r, _, _, _ := newSlice4Router(t)
	code, resp := postUpdate(t, r)
	if code != http.StatusAccepted {
		t.Fatalf("an accepted update must answer 202, got %d (%+v)", code, resp)
	}
	data, _ := resp.Data.(map[string]interface{})
	if data["completed"] != false || data["accepted"] != true {
		t.Errorf("the body must say accepted and NOT completed, got %v", resp.Data)
	}
	if resp.Message == "Stack app update completed" {
		t.Error("the synchronous response claimed completion — R-443")
	}
	deadline := time.Now().Add(5 * time.Second)
	for time.Now().Before(deadline) {
		if st, ok := r.stackMgr.GetStack("app"); ok && !st.Updating {
			if st.UpdatePhase != stacks.UpdatePhaseFailed || st.UpdateError != stacks.MsgUpdatePinFailed {
				t.Errorf("the job's truth must be on the stack: phase=%q err=%q", st.UpdatePhase, st.UpdateError)
			}
			return
		}
		time.Sleep(10 * time.Millisecond)
	}
	t.Fatal("the job never finished")
}