// SPDX-License-Identifier: GPL-3.0-or-later

package main

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"krino/internal/plan"
	"krino/internal/scan"
)

// TestRelWidthAndPadCellCountRunes: C4. relWidth and padCell must measure
// column width in runes, not bytes, or a name carrying diacritics
// misaligns its column - "próba.txt" is 9 runes but 10 bytes (ó is a
// two-byte UTF-8 sequence), one column narrower than its byte length
// would suggest.
func TestRelWidthAndPadCellCountRunes(t *testing.T) {
	rels := []string{"a.txt", "próba.txt"}
	if w := relWidth(rels); w != 9 {
		t.Fatalf("relWidth(%q) = %d, want 9 (rune count of próba.txt, not its %d bytes)", rels, w, len("próba.txt"))
	}
	if got, want := padCell("a.txt", 9), "a.txt    "; got != want {
		t.Fatalf("padCell(%q, 9) = %q, want %q", "a.txt", got, want)
	}
	if got, want := padCell("próba.txt", 9), "próba.txt"; got != want {
		t.Fatalf("padCell(%q, 9) = %q, want %q (already at width: no padding)", "próba.txt", got, want)
	}
}

// TestActionableChainsAgreesWithCountActing is fix wave item 4 / Minor 5:
// countActing (render.go) and actionableChains used to disagree over a
// chain every one of whose steps is skipped (len(Steps) > 0, but every
// step's own Skip is set) - countActing already excluded it from "to act
// on", while actionableChains's own len(Steps) > 0 check still offered it
// for approval, so a directory could print "N scanned · 0 to act on" and
// then still ask the user to approve a file it had just said there were
// none of. Converged on chainActing (render.go), both must now agree.
func TestActionableChainsAgreesWithCountActing(t *testing.T) {
	chains := []plan.Chain{
		{File: scan.File{Rel: "a.txt"}, Steps: []plan.Step{{Kind: plan.Move, Skip: "target exists"}}},
		{File: scan.File{Rel: "b.txt"}, Steps: []plan.Step{{Kind: plan.Move, Dst: "/r/W/b.txt"}}},
	}
	if got := countActing(chains); got != 1 {
		t.Errorf("countActing = %d, want 1 (a.txt is all-skipped)", got)
	}
	actionable := actionableChains(chains)
	if len(actionable) != 1 || actionable[0].File.Rel != "b.txt" {
		t.Errorf("actionableChains = %+v, want only b.txt - an all-skipped chain must never be offered for approval", actionable)
	}
}

// TestAllSkippedDirectoryReportsZeroAndLogsNothing is fix wave item 4 /
// Minor 5 and 6, end to end. Before the fix: a directory whose one file
// matches a rule under (on-conflict skip) - so its single step's own Skip
// is set ("target exists") - printed "0 to act on" (countActing) and then,
// with -y, still ran that chain through Apply anyway (actionableChains'
// own len(Steps) > 0 check approved it regardless), logging a
// run-start/run-end pair holding only a "skipped" entry while the outcome
// line read "0 applied · 0 failed · 0 declined" for a file that had just
// been silently processed. After the fix, the chain is never offered for
// approval, Apply is never even called for this directory, and the journal
// gains nothing at all.
func TestAllSkippedDirectoryReportsZeroAndLogsNothing(t *testing.T) {
	h := home(t)
	dl := filepath.Join(h, "dl")
	if err := os.MkdirAll(filepath.Join(dl, "Out"), 0o755); err != nil {
		t.Fatal(err)
	}
	old := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
	for _, p := range []string{filepath.Join(dl, "a.txt"), filepath.Join(dl, "Out", "a.txt")} {
		if err := os.WriteFile(p, []byte("x"), 0o644); err != nil {
			t.Fatal(err)
		}
		if err := os.Chtimes(p, old, old); err != nil {
			t.Fatal(err)
		}
	}
	if code, _, errOut := runCLI(t, "init"); code != 0 {
		t.Fatal(errOut)
	}
	if code, _, errOut := runCLI(t, "new", "dl", dl); code != 0 {
		t.Fatal(errOut)
	}
	rules := "(path \"~/dl\")\n(min-age 0s)\n(on-conflict skip)\n(rule \"r\" (when (type text)) (move \"Out\"))\n"
	if err := os.WriteFile(filepath.Join(h, ".config", "krino", "dirs", "dl.conf"), []byte(rules), 0o644); err != nil {
		t.Fatal(err)
	}

	code, out, errOut := runCLI(t, "-y")
	if code != 0 {
		t.Fatalf("run: %d %s", code, errOut)
	}
	if !strings.Contains(out, "1 scanned · 0 to act on") {
		t.Errorf("output = %q, want \"0 to act on\"", out)
	}
	if !strings.Contains(out, zeroOutcome) {
		t.Errorf("output = %q, want the honest zero outcome %q", out, zeroOutcome)
	}

	logPath := filepath.Join(h, ".local", "state", "krino", "krino.log")
	data, err := os.ReadFile(logPath)
	if err != nil {
		t.Fatalf("reading the journal: %v", err)
	}
	if len(data) != 0 {
		t.Errorf("journal gained entries for a directory with nothing to act on:\n%s", data)
	}
}

// TestDuplicatesUnderOverlappingDirMoveOnlyTheLooseCopy drives the whole run
// end to end on the shape where a (duplicate "DIR") overlaps the scanned
// tree: a recursive root holding Archive/x.pdf and a loose, older
// x-copy.pdf with the same bytes, and a rule that moves duplicates of
// anything under Archive aside. Every lookup must elect the same original,
// so the archived copy stays where it is and only the loose one is moved;
// an inconsistent election would move both.
func TestDuplicatesUnderOverlappingDirMoveOnlyTheLooseCopy(t *testing.T) {
	h := home(t)
	dl := filepath.Join(h, "dl")
	content := []byte("%PDF acme statement")
	archived := filepath.Join(dl, "Archive", "x.pdf")
	loose := filepath.Join(dl, "x-copy.pdf")
	old := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
	for p, mt := range map[string]time.Time{archived: old.Add(time.Hour), loose: old} {
		if err := os.MkdirAll(filepath.Dir(p), 0o755); err != nil {
			t.Fatal(err)
		}
		if err := os.WriteFile(p, content, 0o644); err != nil {
			t.Fatal(err)
		}
		if err := os.Chtimes(p, mt, mt); err != nil {
			t.Fatal(err)
		}
	}
	if code, _, errOut := runCLI(t, "init"); code != 0 {
		t.Fatal(errOut)
	}
	if code, _, errOut := runCLI(t, "new", "dl", dl); code != 0 {
		t.Fatal(errOut)
	}
	rules := "(path \"~/dl\")\n(recursive yes)\n(min-age 0s)\n" +
		"(rule \"dups\" (when (duplicate \"Archive\")) (move \"~/dupes\") (stop))\n"
	if err := os.WriteFile(filepath.Join(h, ".config", "krino", "dirs", "dl.conf"), []byte(rules), 0o644); err != nil {
		t.Fatal(err)
	}

	code, out, errOut := runCLI(t, "-y")
	if code != 0 {
		t.Fatalf("run: exit %d\nstdout:\n%s\nstderr:\n%s", code, out, errOut)
	}
	moved := filepath.Join(h, "dupes", "x-copy.pdf")
	for _, p := range []string{archived, moved} {
		b, err := os.ReadFile(p)
		if err != nil || string(b) != string(content) {
			t.Errorf("%s: want the content there, got err %v", p, err)
		}
	}
	if _, err := os.Stat(loose); !os.IsNotExist(err) {
		t.Errorf("%s is still in place; want it moved to %s", loose, moved)
	}
}

// TestCheckRefusesDuplicateWithDelete: krino check reports the §4.5
// refusal on stderr and fails, before any run could act on the rule.
func TestCheckRefusesDuplicateWithDelete(t *testing.T) {
	h := home(t)
	dl := filepath.Join(h, "dl")
	if err := os.MkdirAll(dl, 0o755); err != nil {
		t.Fatal(err)
	}
	if code, _, errOut := runCLI(t, "init"); code != 0 {
		t.Fatal(errOut)
	}
	if code, _, errOut := runCLI(t, "new", "dl", dl); code != 0 {
		t.Fatal(errOut)
	}
	rules := "(path \"~/dl\")\n(rule \"d\" (when (duplicate)) (delete))\n"
	if err := os.WriteFile(filepath.Join(h, ".config", "krino", "dirs", "dl.conf"), []byte(rules), 0o644); err != nil {
		t.Fatal(err)
	}
	code, _, errOut := runCLI(t, "check")
	want := `rule "d": (duplicate) cannot be combined with (delete)`
	if code == 0 || !strings.Contains(errOut, want) {
		t.Errorf("check: exit %d, stderr %q; want non-zero and %q", code, errOut, want)
	}
}

// TestDryRunShowsNeverDeletedSkip pins the plan line spec §5.5 names.
func TestDryRunShowsNeverDeletedSkip(t *testing.T) {
	h := home(t)
	dl := filepath.Join(h, "dl")
	old := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
	for name, mt := range map[string]time.Time{"a.pdf": old, "b.pdf": old.Add(time.Hour)} {
		p := filepath.Join(dl, name)
		if err := os.MkdirAll(dl, 0o755); err != nil {
			t.Fatal(err)
		}
		if err := os.WriteFile(p, []byte("%PDF same"), 0o644); err != nil {
			t.Fatal(err)
		}
		if err := os.Chtimes(p, mt, mt); err != nil {
			t.Fatal(err)
		}
	}
	if code, _, errOut := runCLI(t, "init"); code != 0 {
		t.Fatal(errOut)
	}
	if code, _, errOut := runCLI(t, "new", "dl", dl); code != 0 {
		t.Fatal(errOut)
	}
	rules := "(path \"~/dl\")\n(min-age 0s)\n" +
		"(rule \"dupes\" (when (duplicate)) (move \"Dupes\"))\n" +
		"(rule \"cleanup\" (when (matched)) (delete))\n"
	if err := os.WriteFile(filepath.Join(h, ".config", "krino", "dirs", "dl.conf"), []byte(rules), 0o644); err != nil {
		t.Fatal(err)
	}
	code, out, errOut := runCLI(t, "-n")
	if code != 0 {
		t.Fatalf("exit %d: %s", code, errOut)
	}
	if !strings.Contains(out, "skipped: a duplicate is never deleted") {
		t.Errorf("plan lacks the skipped delete:\n%s", out)
	}
	// explain shows it too, for the copy that is the duplicate (triage 30a).
	_, outA, _ := runCLI(t, "explain", filepath.Join(dl, "a.pdf"))
	_, outB, _ := runCLI(t, "explain", filepath.Join(dl, "b.pdf"))
	if strings.Count(outA+outB, "a duplicate is never deleted") != 1 {
		t.Errorf("explain should name the skipped delete for exactly one copy:\n%s\n%s", outA, outB)
	}
}

// TestLaterDirectoryIsNotBlockedByAnEarlierOnesClaims: in a real run each
// directory is applied before the next is planned, so the disk is the
// truth; a path an earlier directory moved a file away from, or planned and
// did not apply, is not "taken" for a later one (triage 28i).
func TestLaterDirectoryIsNotBlockedByAnEarlierOnesClaims(t *testing.T) {
	h := home(t)
	old := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
	for _, p := range []string{"ca/x.txt", "cb/x.txt"} {
		full := filepath.Join(h, p)
		os.MkdirAll(filepath.Dir(full), 0o755)
		os.WriteFile(full, []byte(p), 0o644)
		os.Chtimes(full, old, old)
	}
	if code, _, errOut := runCLI(t, "init"); code != 0 {
		t.Fatal(errOut)
	}
	for _, n := range []string{"ca", "cb"} {
		if code, _, errOut := runCLI(t, "new", n, filepath.Join(h, n)); code != 0 {
			t.Fatal(errOut)
		}
	}
	dirs := filepath.Join(h, ".config", "krino", "dirs")
	os.WriteFile(filepath.Join(dirs, "ca.conf"), []byte("(path \"~/ca\")\n(rule \"away\" (move \"~/elsewhere\"))\n"), 0o644)
	os.WriteFile(filepath.Join(dirs, "cb.conf"), []byte("(path \"~/cb\")\n(on-conflict skip)\n(rule \"in\" (move \"~/ca\"))\n"), 0o644)
	code, out, errOut := runCLI(t, "-y", "ca", "cb")
	if code != 0 {
		t.Fatalf("exit %d\n%s\n%s", code, out, errOut)
	}
	if b, err := os.ReadFile(filepath.Join(h, "ca", "x.txt")); err != nil || string(b) != "cb/x.txt" {
		t.Errorf("cb's x.txt did not move into the place ca's left free: %q, %v\n%s", b, err, out)
	}
}

// devFullFixture builds two directories, d1 and d2, each with two files a
// rule moves, and a log at /dev/full, where every write fails: applying
// anything is a genuine apply error, not a step failure.
func devFullFixture(t *testing.T) {
	t.Helper()
	if _, err := os.Stat("/dev/full"); err != nil {
		t.Skip("no /dev/full on this system")
	}
	h := home(t)
	old := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
	if code, _, errOut := runCLI(t, "init"); code != 0 {
		t.Fatal(errOut)
	}
	for _, n := range []string{"d1", "d2"} {
		for _, name := range []string{"a.pdf", "b.pdf"} {
			p := filepath.Join(h, n, name)
			os.MkdirAll(filepath.Dir(p), 0o755)
			os.WriteFile(p, []byte(n+name), 0o644)
			os.Chtimes(p, old, old)
		}
		if code, _, errOut := runCLI(t, "new", n, filepath.Join(h, n)); code != 0 {
			t.Fatal(errOut)
		}
		os.WriteFile(filepath.Join(h, ".config", "krino", "dirs", n+".conf"), []byte("(path \"~/"+n+"\")\n(rule \"r\" (move \"Out\"))\n"), 0o644)
	}
	f, err := os.OpenFile(filepath.Join(h, ".config", "krino", "krino.conf"), os.O_APPEND|os.O_WRONLY, 0)
	if err != nil {
		t.Fatal(err)
	}
	f.WriteString("(log \"/dev/full\")\n")
	f.Close()
}

// TestApplyErrorExitsOne: an error applying a directory - here the log
// cannot be written - makes krino exit 1 (triage 34m: removing that exit
// code left every test passing).
func TestApplyErrorExitsOne(t *testing.T) {
	devFullFixture(t)
	code, _, errOut := runCLI(t, "-y", "d1")
	if code != 1 || !strings.Contains(errOut, "no space left") {
		t.Errorf("exit %d, stderr %q; want 1 and the write error", code, errOut)
	}
}

// TestWriteStopsKrinoWhenApplyFails: [w] in review stops krino after its
// directory even when applying it fails - the next directory is not planned
// or asked about (review cli F3), driven through the real command with a
// pipe standing in for the terminal (triage 28m).
func TestWriteStopsKrinoWhenApplyFails(t *testing.T) {
	devFullFixture(t)
	r, w, err := os.Pipe()
	if err != nil {
		t.Fatal(err)
	}
	w.WriteString("cyw") // choose per file, yes to a.pdf, write before b.pdf
	w.Close()
	oldStdin, oldTerm := stdin, stdinIsTerminal
	stdin, stdinIsTerminal = r, func() bool { return true }
	t.Cleanup(func() { stdin, stdinIsTerminal = oldStdin, oldTerm })
	code, out, errOut := runCLI(t, "--no-pager")
	if code != 1 {
		t.Errorf("exit %d, want 1\n%s\n%s", code, out, errOut)
	}
	if strings.Contains(out, "krino: d2") {
		t.Errorf("d2 was planned after [w]:\n%s", out)
	}
}

// TestLaterDirectoryNeverOverwritesAnEarlierOnesResult: what an earlier
// directory of the run put somewhere stays claimed, so a later directory's
// (on-conflict overwrite) takes a free name instead of trashing it - as a
// dry run of the same two directories shows (plan 11 review M1).
func TestLaterDirectoryNeverOverwritesAnEarlierOnesResult(t *testing.T) {
	h := home(t)
	old := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
	if code, _, errOut := runCLI(t, "init"); code != 0 {
		t.Fatal(errOut)
	}
	for _, n := range []string{"a", "b"} {
		p := filepath.Join(h, n, "x.pdf")
		os.MkdirAll(filepath.Dir(p), 0o755)
		os.WriteFile(p, []byte("from "+n), 0o644)
		os.Chtimes(p, old, old)
		if code, _, errOut := runCLI(t, "new", n, filepath.Join(h, n)); code != 0 {
			t.Fatal(errOut)
		}
		os.WriteFile(filepath.Join(h, ".config", "krino", "dirs", n+".conf"), []byte("(path \"~/"+n+"\")\n(on-conflict overwrite)\n(rule \"out\" (move \"~/Out\"))\n"), 0o644)
	}
	if code, out, errOut := runCLI(t, "-y", "a", "b"); code != 0 {
		t.Fatalf("exit %d\n%s\n%s", code, out, errOut)
	}
	for rel, want := range map[string]string{"Out/x.pdf": "from a", "Out/x_1.pdf": "from b"} {
		if b, err := os.ReadFile(filepath.Join(h, rel)); err != nil || string(b) != want {
			t.Errorf("%s: %q, %v; want %q", rel, b, err, want)
		}
	}
	if entries, _ := os.ReadDir(filepath.Join(h, ".local", "share", "Trash", "files")); len(entries) != 0 {
		t.Errorf("the Trash holds %d entries; nothing should have been displaced", len(entries))
	}
}

// TestOnlyWhereFilesEndedUpStaysClaimed: a path an earlier directory's file
// passed through and left - renamed, then moved on - is free for a later
// directory; only where files ended up stays claimed (plan 11 re-check).
func TestOnlyWhereFilesEndedUpStaysClaimed(t *testing.T) {
	h := home(t)
	old := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
	if code, _, errOut := runCLI(t, "init"); code != 0 {
		t.Fatal(errOut)
	}
	for _, n := range []string{"a", "b"} {
		p := filepath.Join(h, n, "x.pdf")
		os.MkdirAll(filepath.Dir(p), 0o755)
		os.WriteFile(p, []byte("from "+n), 0o644)
		os.Chtimes(p, old, old)
		if code, _, errOut := runCLI(t, "new", n, filepath.Join(h, n)); code != 0 {
			t.Fatal(errOut)
		}
	}
	dirs := filepath.Join(h, ".config", "krino", "dirs")
	os.WriteFile(filepath.Join(dirs, "a.conf"), []byte("(path \"~/a\")\n(rule \"r\" (rename \"x-r.pdf\") (move \"~/Out\"))\n"), 0o644)
	os.WriteFile(filepath.Join(dirs, "b.conf"), []byte("(path \"~/b\")\n(rule \"r\" (rename \"x-r.pdf\") (move \"~/a\"))\n"), 0o644)
	if code, out, errOut := runCLI(t, "-y", "a", "b"); code != 0 {
		t.Fatalf("exit %d\n%s\n%s", code, out, errOut)
	}
	if b, err := os.ReadFile(filepath.Join(h, "a", "x-r.pdf")); err != nil || string(b) != "from b" {
		t.Errorf("a/x-r.pdf: %q, %v; want b's file under its planned name", b, err)
	}
}