package backup

import (
	"go/ast"
	"go/parser"
	"go/token"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

// R-383 — the double-failure message claimed the undo copy EXISTED without ever asking the disk.
//
// THE DEFECT. The branch where BOTH the replay and the rollback failed ended with
// „a korábbi állapot mentése megvan: <file>". The filename came from the path `writeSafetyDump`
// returned. One of the two ways `rollbackSafetyDump` fails is that the file is NOT THERE — so the
// sentence was most likely to be false in precisely the case it was printed. Measured twice live, on
// v0.220.2 and v0.221.1.
//
// THE LAYER. The guard sits on the phrase builder, because that is where the claim is MADE. A test
// at the reconstitute level would need a whole failed off-site restore to reach one sentence, and the
// AST test below is what pins that the sentence is still wired to this builder.
//
// RED-PROOF (observed, see REPORT.md): replace undoCopyPhrase's body with the pre-fix shape
//
//	return "a korábbi állapot mentése megvan: " + filepath.Base(set.First())
//
// and TestR383_AbsentUndoCopyIsNotClaimedToExist fails with the message asserting the file exists.
func TestR383_AbsentUndoCopyIsNotClaimedToExist(t *testing.T) {
	dir := t.TempDir()
	real := filepath.Join(dir, "pre-restore-20260823T120000Z-app-postgres.sql")
	if err := os.WriteFile(real, []byte("-- a real dump\n"), 0o600); err != nil {
		t.Fatal(err)
	}
	gone := filepath.Join(dir, "pre-restore-20260823T120000Z-app-mariadb.sql")
	empty := filepath.Join(dir, "pre-restore-20260823T120000Z-app-empty.sql")
	if err := os.WriteFile(empty, nil, 0o600); err != nil {
		t.Fatal(err)
	}

	set := func(paths ...string) safetyDumpSet {
		s := safetyDumpSet{Stamp: "20260823T120000Z"}
		for _, p := range paths {
			s.Files = append(s.Files, safetyDumpFile{Path: p})
		}
		return s
	}

	cases := []struct {
		name        string
		set         safetyDumpSet
		mustContain []string
		mustNotHave []string
	}{
		{
			name:        "present — the operator still gets the filename",
			set:         set(real),
			mustContain: []string{"megvan", filepath.Base(real)},
		},
		{
			// THE DEFECT ITSELF: the file is gone and the sentence used to say it was there.
			name:        "absent — must NOT claim it exists, must still name where it should be",
			set:         set(gone),
			mustContain: []string{"NEM találjuk", filepath.Base(gone)},
			mustNotHave: []string{"mentése megvan"},
		},
		{
			// A 0-byte dump restores nothing. Calling it present is the same false reassurance.
			name:        "zero-length — counts as missing",
			set:         set(empty),
			mustContain: []string{"NEM találjuk", filepath.Base(empty)},
			mustNotHave: []string{"mentése megvan"},
		},
		{
			name:        "partial — both halves named, neither hidden",
			set:         set(real, gone),
			mustContain: []string{"RÉSZBEN", filepath.Base(real), "HIÁNYZIK", filepath.Base(gone)},
		},
		{
			name:        "no undo was ever written — said plainly, not silently",
			set:         set(),
			mustContain: []string{"nem készült"},
			mustNotHave: []string{"megvan"},
		},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			got := newNoteManager(t).undoCopyPhrase(tc.set)
			for _, want := range tc.mustContain {
				if !strings.Contains(got, want) {
					t.Errorf("phrase %q does not contain %q", got, want)
				}
			}
			for _, bad := range tc.mustNotHave {
				if strings.Contains(got, bad) {
					t.Errorf("phrase %q contains %q — it asserts a file that is not on disk", got, bad)
				}
			}
		})
	}
}

// The seam, through production wiring (§10). A correct phrase builder nobody calls is R-106's defect
// — "seam built but never wired", four instances in this project. This walks the AST rather than
// grepping for a substring, so a commented-out call or a similarly-named local cannot satisfy it.
func TestR383_TheDoubleFailureMessageIsWiredToTheBuilder(t *testing.T) {
	fset := token.NewFileSet()
	f, err := parser.ParseFile(fset, "offbox_reconstitute.go", nil, 0)
	if err != nil {
		t.Fatalf("parse: %v", err)
	}

	var holdCalled, phraseCalled bool
	ast.Inspect(f, func(n ast.Node) bool {
		call, ok := n.(*ast.CallExpr)
		if !ok {
			return true
		}
		switch fn := call.Fun.(type) {
		case *ast.SelectorExpr:
			// v0.254.0 (R-557 release C): undoCopyPhrase became a METHOD, because a saved note is
			// rendered in the box's language and that needs the Manager. A method call is a
			// SelectorExpr, not an Ident — so it is matched here as well as below, and the test keeps
			// asserting what it always asserted rather than passing because the shape moved.
			if fn.Sel.Name == "holdAppAfterFailedRollback" {
				holdCalled = true
			}
			if fn.Sel.Name == "undoCopyPhrase" {
				phraseCalled = true
			}
		case *ast.Ident:
			if fn.Name == "undoCopyPhrase" {
				phraseCalled = true
			}
		}
		return true
	})
	if !holdCalled {
		t.Fatal("holdAppAfterFailedRollback is no longer called — the double-failure branch moved; " +
			"re-point this test before trusting it")
	}
	if !phraseCalled {
		t.Fatal("undoCopyPhrase is never called from offbox_reconstitute.go — the message is back to " +
			"asserting a file it did not check (R-383)")
	}

	// And the claim must not be re-typed OUTSIDE the builder. Inside undoCopyPhrase it is the
	// verified branch and belongs there; anywhere else it is unconditional again, which is R-383.
	// The builder's extent comes from the AST, so this cannot be defeated by moving the function.
	var lo, hi token.Pos
	for _, d := range f.Decls {
		if fd, ok := d.(*ast.FuncDecl); ok && fd.Name.Name == "undoCopyPhrase" {
			lo, hi = fd.Pos(), fd.End()
		}
	}
	if lo == token.NoPos {
		t.Fatal("undoCopyPhrase is not declared in offbox_reconstitute.go")
	}
	ast.Inspect(f, func(n ast.Node) bool {
		lit, ok := n.(*ast.BasicLit)
		if !ok || lit.Kind != token.STRING {
			return true
		}
		if lit.Pos() >= lo && lit.End() <= hi {
			return true // inside the builder — the verified branch
		}
		if strings.Contains(lit.Value, "állapot mentése megvan") {
			t.Errorf("%s: the unconditional claim is back outside undoCopyPhrase: %s",
				fset.Position(lit.Pos()), lit.Value)
		}
		return true
	})
}