package backup

import (
	"context"
	"log"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"
)

// R-645 (09 §3 decision 142) — the night backup skips an app whose pinned version is not the version
// it runs.
//
// THE HAND-LIFT SHAPE, measured 2026-09-23 on 9202: docmost was HELD after a failed 0.95.0 → 0.96.0
// update; `--clear-restore-hold docmost` + the restart ran, and three seconds later the capture wrote
// the 0.96.0 definition into the unit the hold sentence had named. This drives the whole night run
// (DB leg, volume leg, capture) and then Tier 2 over that state — the hold is gone, the stack dir names
// the failed version, the pin says 0.96.0, the running record says 0.95.0 — and asserts the
// CONSEQUENCE: the good unit's tree is byte-identical afterwards, and its compose still names 0.95.0.
//
// COMPANION RED-PROOF: make versionSkip return ("", false) — the unit's compose/docker-compose.yml then
// names docmost/docmost:0.96.0 and the tree fingerprint differs, and this test fails.
func TestR645_HandLiftedHoldKeepsTheGoodUnit(t *testing.T) {
	h := newAdmissionHarness(t, "docmost", "free")
	h.m.settings = slice4Settings(t)
	ns := h.nsRoot()

	// The good unit: written by an earlier backup of 0.95.0. Its manifest carries no data stamps (a unit
	// from before v0.275.0), so nothing else in the capture freezes its definition — this skip is the
	// only thing standing between the failed definition and the restore point.
	h.seedUnit(t, "docmost", 0)
	goodCompose := "services:\n  docmost:\n    image: docmost/docmost:0.95.0\n"
	if err := os.WriteFile(filepath.Join(RecoveryUnitComposePath(ns, "docmost"), "docker-compose.yml"), []byte(goodCompose), 0o644); err != nil {
		t.Fatal(err)
	}
	// The stack dir after the failed update: it names the version that just failed.
	for _, app := range []string{"docmost", "free"} {
		dir := filepath.Join(h.dir, "stacks", app)
		if err := os.MkdirAll(dir, 0o755); err != nil {
			t.Fatal(err)
		}
		img := "docmost/docmost:0.96.0"
		if app == "free" {
			img = "free/free:1.0"
		}
		if err := os.WriteFile(filepath.Join(dir, "docker-compose.yml"), []byte("services:\n  "+app+":\n    image: "+img+"\n"), 0o644); err != nil {
			t.Fatal(err)
		}
	}

	// The hold existed and was lifted by hand — exactly the operator CLI's act.
	if err := h.m.HoldAfterFailedUpdate("docmost", time.Now(), time.Now(), UpdateTierLocal); err != nil {
		t.Fatal(err)
	}
	if _, err := h.m.settings.ClearRestoreHold("docmost"); err != nil {
		t.Fatal(err)
	}
	if held, _ := h.m.RestoreHoldFor("docmost"); held {
		t.Fatal("setup: the hold must be lifted")
	}

	// stacks.Manager.PinNotRunning's answer for this shape (pinned by TestR645_PinNotRunning_* there).
	h.m.SetVersionCheck(func(name string) (string, bool) {
		if name == "docmost" {
			return "docmost runs docmost/docmost:0.95.0, pinned docmost/docmost:0.96.0", true
		}
		return "", false
	})

	var dumped []string
	h.m.discoverDBs = func(context.Context) ([]DiscoveredDB, error) {
		return []DiscoveredDB{
			{StackName: "docmost", ContainerName: "docmost-postgres"},
			{StackName: "free", ContainerName: "free-postgres"},
		}, nil
	}
	h.m.dumpOne = func(_ context.Context, db DiscoveredDB, dumpDir string, _ *log.Logger, _ bool) DumpResult {
		dumped = append(dumped, db.StackName)
		_ = os.MkdirAll(dumpDir, 0o755)
		p := filepath.Join(dumpDir, db.StackName+"-postgres.sql")
		_ = os.WriteFile(p, []byte("-- FRESH DUMP OF THE FAILED VERSION\n"), 0o644)
		return DumpResult{DB: db, FilePath: p, Size: 36}
	}

	unitRoot := RecoveryUnitPath(ns, "docmost")
	before := treeFingerprint(t, unitRoot)

	_ = h.m.runDBDumpsInternal(context.Background())
	var mirrored []string
	h.m.perAppTier2 = func(name string) error { mirrored = append(mirrored, name); return nil }
	h.m.RunAllTier2()

	if after := treeFingerprint(t, unitRoot); after != before {
		t.Errorf("the good unit was rewritten by the night run after a hand-lifted hold:\nbefore:\n%s\nafter:\n%s", before, after)
	}
	b, _ := os.ReadFile(filepath.Join(RecoveryUnitComposePath(ns, "docmost"), "docker-compose.yml"))
	if !strings.Contains(string(b), "docmost/docmost:0.95.0") {
		t.Errorf("the unit's definition must still be the good 0.95.0 one, got:\n%s", b)
	}
	for _, list := range [][]string{dumped, h.volDumped, h.prov.stopped, mirrored} {
		for _, n := range list {
			if n == "docmost" {
				t.Errorf("a night leg touched docmost (db=%v vol=%v stopped=%v mirrored=%v)", dumped, h.volDumped, h.prov.stopped, mirrored)
			}
		}
	}
	// It says so in the log — the operator's half of the ruling.
	if !strings.Contains(h.logs.String(), "Recovery unit NOT captured for docmost — it is not running its pinned version") {
		t.Errorf("the skip must be logged, log:\n%s", h.logs.String())
	}
	// Positive control: the app that runs its pin is backed up as before.
	if len(dumped) != 1 || dumped[0] != "free" || len(h.volDumped) != 1 || h.volDumped[0] != "free" || len(mirrored) != 1 || mirrored[0] != "free" {
		t.Errorf("positive control: the other app must still be dumped and mirrored (db=%v vol=%v mirrored=%v)", dumped, h.volDumped, mirrored)
	}
	if _, err := os.Stat(RecoveryUnitManifestPath(ns, "free")); err != nil {
		t.Errorf("positive control: the other app's unit must be captured: %v", err)
	}
}

// The page's half: the household reads one plain sentence, in their language; nothing when the app
// runs its pin or when nothing is wired (unknown never skips).
func TestR645_VersionSkipSentence(t *testing.T) {
	m := &Manager{}
	if skip, why := m.VersionSkipFor("docmost", "hu"); skip || why != "" {
		t.Fatalf("no check wired must read as no skip, got (%v, %q)", skip, why)
	}
	m.SetVersionCheck(func(name string) (string, bool) { return "x", name == "docmost" })
	skip, hu := m.VersionSkipFor("docmost", "hu")
	if !skip || !strings.Contains(hu, "docmost") || !strings.Contains(hu, "jszakai ment") || !strings.Contains(hu, "Vedd fel") {
		t.Errorf("hu sentence = %q", hu)
	}
	_, en := m.VersionSkipFor("docmost", "en")
	if !strings.Contains(en, "night backup leaves it out") || strings.Contains(en, "jszakai") {
		t.Errorf("en sentence = %q", en)
	}
	if skip, _ := m.VersionSkipFor("free", "hu"); skip {
		t.Error("an app running its pin must not read as skipped")
	}
}