package checks

import (
	"fmt"
	"io/fs"
	"os"
	"path"
	"regexp"
	"runtime"
	"sort"
	"strings"
	"sync"
	"testing"
	"testing/fstest"
	"time"
	"unicode"
)

// One word per thing, checked (words.py until ADR 0527; ADR 0244). The glossary (00-META/glossary.md) is the
// authority on the mesh's words. It names the words it retired on one fixed kind of line, so a program can read them:
//
//	*Not:* ~~control plane~~, ~~overlay~~ (hq)
//
// A struck word with no scope is retired everywhere; `(hq)` retires it in this repository's prose only; `(tools)`
// in the descriptions of the mesh's tools only. And it names code that still carries an old name until it is renamed:
//
//	*Identifier until renamed:* `mesh-host` - the repository, binary and service unit
//
// An identifier is allowed inside a code span and nowhere else.
//
// What is enforced:
//
//	retired  no retired word of scope hq (or none), and no identifier, in running prose of a checked document.
//	         Running prose is what is left once code blocks, code spans, block quotes, text in quotation marks,
//	         struck-through text, link targets, HTML comments and frontmatter are taken out. A word's plural is the word.
//	unique   no head word heads two entries, and none is also struck through on a *Not:* line.
//	lines    no daemon's line in a checked document (ADR 0272, its insight of 2026-10-09): the operator types `nox`.
//	copy     with MESH_CATALOG_DIR set to a checkout of the catalogue, its copies of the retired words and the
//	         daemons' lines equal this glossary's and this list (skipped, with its reason, when unset).
//
// Checked documents: 00-META/, 03-DESIGN/ (both layers), AGENTS.md and README.md, always; an issue opened on or after
// wordsFrom (on or after linesFrom for the lines). A document that cannot be reworded in the change that found it is
// named, with a date and a reason, in words-allowed.md beside this file; an entry past its date fails like the word
// itself, and so does an entry for a document that no longer needs it.

const (
	glossaryFile = "00-META/glossary.md"
	allowedFile  = "00-META/checks/words-allowed.md"
	// The day the rule began (ADR 0244): issues opened from it on are held to it.
	wordsFrom = "2026-10-07"
	// The day the daemons' lines rule began.
	linesFrom = "2026-10-09"
)

var wordsAlways = []string{"00-META/", "03-DESIGN/", "AGENTS.md", "README.md"}

// daemonLines are the daemons' lines (ADR 0272): each daemon's commands. "alone" is a command that is a line by
// itself; "with an argument" one that is a line only when written as one ("the mesh-controller module" is prose;
// `mesh-controller module check ...` is a line). The node-engine's install-time subcommands are not lines here.
var daemonLines = []struct {
	daemon, alone, withArgument string
}{
	{"mesh-controller",
		"adopt assign broker cancel cleanup collect conditions converge doctor durations hand-act hand-acts healers identity kill licence " +
			"migrate operator pause pin plan prepare push rebuild rehearse replay resume retire rollout rotate secret settings status token " +
			"unassign unpin upgrade",
		"artifacts ask builds bus collection data delivery images mirrors module node overlay plans queue seat seats take version"},
	{"mesh-host", "apply bundle enrol enroll hand-over help inventory key overlay owned profile reconcile run version", ""},
	{"nox-mesh-host", "hand-over", ""},
}

var (
	notLineRx   = regexp.MustCompile(`(?m)^\s*(?:[-*]\s+)?\*Not:\*(.*)$`)
	struckRx    = regexp.MustCompile(`~~([^~]+)~~(?:\s*\((hq|tools)\))?`)
	identLineRx = regexp.MustCompile(`(?m)^\s*(?:[-*]\s+)?\*Identifier until renamed:\*(.*)$`)
	spanRx      = regexp.MustCompile("`([^`]+)`")
	headRx      = regexp.MustCompile(`(?m)^\s*-\s+\*\*([^*]+)\*\*`)
	openedRx    = regexp.MustCompile(`(?m)^opened:\s*(\S+)`)
)

type retiredWord struct{ word, scope string }

// parseGlossary reads the retired words with their scope, the identifiers and the head words from the glossary.
func parseGlossary(text string) (retired []retiredWord, identifiers, heads []string) {
	for _, m := range notLineRx.FindAllStringSubmatch(text, -1) {
		for _, s := range struckRx.FindAllStringSubmatch(m[1], -1) {
			scope := s[2]
			if scope == "" {
				scope = "all"
			}
			for _, one := range strings.Split(s[1], " / ") {
				retired = append(retired, retiredWord{strings.TrimSpace(one), scope})
			}
		}
	}
	for _, m := range identLineRx.FindAllStringSubmatch(text, -1) {
		for _, s := range spanRx.FindAllStringSubmatch(m[1], -1) {
			identifiers = append(identifiers, strings.TrimSpace(s[1]))
		}
	}
	for _, m := range headRx.FindAllStringSubmatch(text, -1) {
		for _, h := range strings.Split(m[1], " / ") {
			heads = append(heads, strings.TrimSpace(h))
		}
	}
	return
}

func isWordRune(r rune) bool {
	return unicode.IsLetter(r) || unicode.IsDigit(r) || r == '_' || r == '-'
}

// findBounded returns the start offsets of the matches of rx that are whole words: no word character or hyphen
// before or after (the lookarounds of the Python check, which RE2 has not).
func findBounded(rx *regexp.Regexp, text string) []int {
	var out []int
	pos := 0
	for pos <= len(text) {
		loc := rx.FindStringIndex(text[pos:])
		if loc == nil {
			break
		}
		start, end := pos+loc[0], pos+loc[1]
		before, after := true, true
		if start > 0 {
			r := []rune(text[max(0, start-4):start])
			before = !isWordRune(r[len(r)-1])
		}
		if end < len(text) {
			r := []rune(text[end:min(len(text), end+4)])
			after = !isWordRune(r[0])
		}
		if before && after {
			out = append(out, start)
			pos = end
			if end == start {
				pos++
			}
		} else {
			pos = start + 1
		}
	}
	return out
}

// wordRegexp matches a word whole, case-insensitively; a space in the word matches a space, a line break or a hyphen.
// The plural is the word too: its last part may end in s or es ("alerts", "control planes").
func wordRegexp(word string) *regexp.Regexp {
	var parts []string
	for _, p := range strings.Fields(word) {
		parts = append(parts, regexp.QuoteMeta(p))
	}
	return regexp.MustCompile(`(?i)` + strings.Join(parts, `[\s-]+`) + `(?:e?s)?`)
}

// blank replaces every byte of s but the line breaks, so offsets and line numbers hold.
func blank(s string) string {
	b := []byte(s)
	for i, c := range b {
		if c != '\n' {
			b[i] = ' '
		}
	}
	return string(b)
}

func blankFrontmatter(text string) string {
	if strings.HasPrefix(text, "---\n") {
		if end := strings.Index(text[4:], "\n---"); end != -1 {
			end += 4
			return blank(text[:end+4]) + text[end+4:]
		}
	}
	return text
}

func blankAll(text string, steps []*regexp.Regexp) string {
	for _, rx := range steps {
		text = rx.ReplaceAllStringFunc(text, blank)
	}
	return text
}

func compileAll(patterns ...string) []*regexp.Regexp {
	var out []*regexp.Regexp
	for _, p := range patterns {
		out = append(out, regexp.MustCompile(p))
	}
	return out
}

// What is not the document's own words, in the order it is taken out.
const (
	stepComment     = `(?s)<!--.*?-->`
	stepBlockQuote  = `(?m)^\s*>.*$`
	stepLinkTarget  = `\]\([^)\s]*\)`
	stepStruck      = `~~[^~\n]+~~`
	stepQuoted      = `"[^"\n]*"`
	stepCurlyDouble = `\x{201c}[^\x{201d}]*\x{201d}`
	stepCurlySingle = `\x{2018}[^\x{2019}\n]*\x{2019}`
)

var (
	proseSteps = compileAll("(?ms)^\\s*```.*?^\\s*```", stepComment, stepBlockQuote, "`[^`\\n]+`", stepLinkTarget, stepStruck,
		stepQuoted, stepCurlyDouble, stepCurlySingle)
	// In the glossary the *Not:* and *Identifier until renamed:* lines name the retired words, so they are taken out first.
	glossaryProseSteps = append(compileAll(notLineRx.String(), identLineRx.String()), proseSteps...)
	// The daemons' lines are looked for in the document's own words: a code block and a code span are kept, since a
	// line to type is written in one.
	ownWordsSteps = compileAll(stepComment, stepBlockQuote, stepLinkTarget, stepStruck, stepQuoted, stepCurlyDouble, stepCurlySingle)
)

// prose is the text with everything that is not running prose blanked, keeping offsets and line numbers.
func prose(text string, glossaryDoc bool) string {
	text = blankFrontmatter(text)
	if glossaryDoc {
		return blankAll(text, glossaryProseSteps)
	}
	return blankAll(text, proseSteps)
}

func ownWords(text string) string { return blankAll(blankFrontmatter(text), ownWordsSteps) }

// issueDocuments lists the issue reports' files opened on or after since.
func issueDocuments(fsys fs.FS, since string) []string {
	var out []string
	entries, _ := fs.ReadDir(fsys, "04-ISSUES")
	for _, e := range entries {
		if !e.IsDir() {
			continue
		}
		head := readFile(fsys, path.Join("04-ISSUES", e.Name(), "00-report.md"))
		front := ""
		if strings.HasPrefix(head, "---\n") {
			if end := strings.Index(head[4:], "\n---"); end != -1 {
				if m := openedRx.FindStringSubmatch(head[4 : 4+end]); m != nil {
					front = m[1]
				}
			}
		}
		if front == "" || front < since {
			continue
		}
		files, _ := fs.ReadDir(fsys, path.Join("04-ISSUES", e.Name()))
		for _, f := range files {
			if strings.HasSuffix(f.Name(), ".md") {
				out = append(out, path.Join("04-ISSUES", e.Name(), f.Name()))
			}
		}
	}
	return out
}

// perDocument runs fn over the documents on all processors (the unit level is short) and joins the problems in
// the documents' order.
func perDocument(docs []string, fn func(doc string) []string) []string {
	results := make([][]string, len(docs))
	var wg sync.WaitGroup
	sem := make(chan struct{}, runtime.NumCPU())
	for i, d := range docs {
		wg.Add(1)
		sem <- struct{}{}
		go func() {
			defer wg.Done()
			results[i] = fn(d)
			<-sem
		}()
	}
	wg.Wait()
	var out []string
	for _, r := range results {
		out = append(out, r...)
	}
	return out
}

func checkedDocuments(fsys fs.FS, since string) []string {
	var docs []string
	for _, entry := range wordsAlways {
		if strings.HasSuffix(entry, "/") {
			_ = fs.WalkDir(fsys, strings.TrimSuffix(entry, "/"), func(p string, d fs.DirEntry, err error) error {
				if err == nil && !d.IsDir() && strings.HasSuffix(p, ".md") {
					docs = append(docs, p)
				}
				return nil
			})
		} else if _, err := fs.Stat(fsys, entry); err == nil {
			docs = append(docs, entry)
		}
	}
	return append(docs, issueDocuments(fsys, since)...)
}

var dateRx = regexp.MustCompile(`^\d{4}-\d{2}-\d{2}$`)

// parseAllowed reads words-allowed.md: one row per document, | `document` | until | why |. Until is a date, after
// which the allowance fails like the words themselves. The clock is the caller's: today is YYYY-MM-DD.
func parseAllowed(text, today string) (allowed map[string]string, problems []string) {
	allowed = map[string]string{}
	for _, line := range strings.Split(text, "\n") {
		cells := strings.Split(strings.Trim(strings.TrimSpace(line), "|"), "|")
		if len(cells) != 3 {
			continue
		}
		for i := range cells {
			cells[i] = strings.TrimSpace(cells[i])
		}
		if !strings.HasPrefix(cells[0], "`") {
			continue
		}
		doc, until, why := strings.Trim(cells[0], "`"), cells[1], cells[2]
		if why == "" {
			problems = append(problems, fmt.Sprintf("%s: the allowance for %s gives no reason", allowedFile, doc))
		}
		if !dateRx.MatchString(until) {
			problems = append(problems, fmt.Sprintf("%s: the allowance for %s has no date", allowedFile, doc))
			continue
		}
		if until < today {
			problems = append(problems, fmt.Sprintf("%s: the allowance for %s ran out on %s — reword it", allowedFile, doc, until))
			continue
		}
		allowed[doc] = until
	}
	return
}

func checkRetired(fsys fs.FS, retired []retiredWord, identifiers []string, today string) []string {
	allowance, out := parseAllowed(readFile(fsys, allowedFile), today)
	type matcher struct {
		word string
		rx   *regexp.Regexp
		why  string
	}
	var words []matcher
	for _, r := range retired {
		if r.scope == "all" || r.scope == "hq" {
			words = append(words, matcher{r.word, wordRegexp(r.word), "retired"})
		}
	}
	for _, i := range identifiers {
		words = append(words, matcher{i, wordRegexp(i), "an identifier, allowed only in a code span"})
	}
	var mu sync.Mutex
	used := map[string]bool{}
	out = append(out, perDocument(checkedDocuments(fsys, wordsFrom), func(d string) []string {
		var found []string
		text := prose(readFile(fsys, d), d == glossaryFile)
		lower := strings.ToLower(text)
		for _, w := range words {
			// Every match holds the word's first part literally, so a text without it is not searched (the unit level is short).
			if !strings.Contains(lower, strings.ToLower(strings.Fields(w.word)[0])) {
				continue
			}
			for _, start := range findBounded(w.rx, text) {
				if _, ok := allowance[d]; ok {
					mu.Lock()
					used[d] = true
					mu.Unlock()
					continue
				}
				m := w.rx.FindString(text[start:])
				found = append(found, fmt.Sprintf("%s:%d: %q is %s (glossary)", d, lineOf(text, start), strings.ReplaceAll(m, "\n", " "), w.why))
			}
		}
		return found
	})...)
	var unused []string
	for d := range allowance {
		if !used[d] {
			unused = append(unused, d)
		}
	}
	sort.Strings(unused)
	for _, d := range unused {
		out = append(out, fmt.Sprintf("%s: %s no longer uses a retired word — remove its allowance", allowedFile, d))
	}
	return out
}

func checkUnique(retired []retiredWord, heads []string) []string {
	var out []string
	seen := map[string]bool{}
	for _, h := range heads {
		k := strings.ToLower(h)
		if seen[k] {
			out = append(out, fmt.Sprintf("%s: %q heads two entries", glossaryFile, h))
		}
		seen[k] = true
	}
	for _, r := range retired {
		if seen[strings.ToLower(r.word)] {
			out = append(out, fmt.Sprintf("%s: %q is a head word and also retired", glossaryFile, r.word))
		}
	}
	return out
}

// linesList is the daemons' lines as the catalogue's copy lists them: "<daemon> <command>", with " …" when an
// argument must follow.
func linesList() []string {
	var out []string
	for _, d := range daemonLines {
		for _, c := range strings.Fields(d.alone) {
			out = append(out, d.daemon+" "+c)
		}
		for _, c := range strings.Fields(d.withArgument) {
			out = append(out, d.daemon+" "+c+" …")
		}
	}
	sort.Strings(out)
	return out
}

func checkLines(fsys fs.FS) []string {
	type pat struct {
		daemon, command string
		rx              *regexp.Regexp
		bounded         bool
	}
	var pats []pat
	for _, d := range daemonLines {
		dq := regexp.QuoteMeta(d.daemon)
		for _, c := range strings.Fields(d.alone) {
			pats = append(pats, pat{d.daemon, c, regexp.MustCompile(dq + `\s+` + regexp.QuoteMeta(c)), true})
		}
		for _, c := range strings.Fields(d.withArgument) {
			// A line only when written as one: at the start of a line or a code span, a prompt allowed, an argument after.
			pats = append(pats, pat{d.daemon, c, regexp.MustCompile("(?m)(?:^|`)[ \\t]*(?:\\$[ \\t]*)?(" + dq + `\s+` + regexp.QuoteMeta(c) + "\\s+[^\\s`])"), false})
		}
	}
	return perDocument(checkedDocuments(fsys, linesFrom), func(d string) []string {
		var out []string
		text := ownWords(readFile(fsys, d))
		for _, p := range pats {
			if !strings.Contains(text, p.daemon) {
				continue
			}
			var starts []int
			if p.bounded {
				starts = findBounded(p.rx, text)
			} else {
				for _, loc := range p.rx.FindAllStringSubmatchIndex(text, -1) {
					starts = append(starts, loc[2])
				}
			}
			for _, s := range starts {
				out = append(out, fmt.Sprintf("%s:%d: `%s %s` is a daemon's line — the operator types `nox …` (ADR 0272)", d, lineOf(text, s), p.daemon, p.command))
			}
		}
		return out
	})
}

func toolsList(retired []retiredWord) []string {
	seen := map[string]bool{}
	var out []string
	for _, r := range retired {
		if (r.scope == "all" || r.scope == "tools") && !seen[r.word] {
			seen[r.word] = true
			out = append(out, r.word)
		}
	}
	sort.Slice(out, func(i, j int) bool { return strings.ToLower(out[i]) < strings.ToLower(out[j]) })
	return out
}

func readList(file string) ([]string, error) {
	b, err := os.ReadFile(file)
	if err != nil {
		return nil, err
	}
	var out []string
	for _, l := range strings.Split(string(b), "\n") {
		if l = strings.TrimSpace(l); l != "" && !strings.HasPrefix(l, "#") {
			out = append(out, l)
		}
	}
	return out, nil
}

// checkCopy compares the catalogue's copies of the retired words and the daemons' lines with this glossary's. A
// difference names what the copy should list, so regenerating it is copying that from the failure.
func checkCopy(catalogue string, retired []retiredWord) []string {
	var out []string
	copyWords, err := readList(path.Join(catalogue, "retired-words"))
	if err != nil {
		return []string{"the catalogue's copy of the retired words cannot be read: " + err.Error()}
	}
	sort.Slice(copyWords, func(i, j int) bool { return strings.ToLower(copyWords[i]) < strings.ToLower(copyWords[j]) })
	want := toolsList(retired)
	if strings.Join(copyWords, "\n") != strings.Join(want, "\n") {
		out = append(out, "the catalogue's retired-words differs from the glossary: it should list "+strings.Join(want, ", "))
	}
	copyLines, err := readList(path.Join(catalogue, "retired-lines"))
	if err != nil {
		return append(out, "the catalogue's copy of the daemons' lines cannot be read: "+err.Error())
	}
	sort.Strings(copyLines)
	if strings.Join(copyLines, "\n") != strings.Join(linesList(), "\n") {
		out = append(out, "the catalogue's retired-lines differs from this check's list: it should list, one per line:\n"+strings.Join(linesList(), "\n"))
	}
	return out
}

// The real tree.

func today() string { return time.Now().Format("2006-01-02") }

func TestWordsGlossaryNamesRetiredWords(t *testing.T) {
	retired, identifiers, heads := parseGlossary(readFile(rootFS(), glossaryFile))
	if len(retired) == 0 {
		t.Fatal("the glossary names no retired word on a *Not:* line — the check would pass on anything")
	}
	if len(identifiers) == 0 || len(heads) == 0 {
		t.Errorf("the glossary names %d identifiers and %d head words; both are expected", len(identifiers), len(heads))
	}
}

func TestWordsEachHeadWordHeadsOneEntry(t *testing.T) {
	retired, _, heads := parseGlossary(readFile(rootFS(), glossaryFile))
	expectNone(t, checkUnique(retired, heads))
}

func TestWordsNoRetiredWordInRunningProse(t *testing.T) {
	retired, identifiers, _ := parseGlossary(readFile(rootFS(), glossaryFile))
	expectNone(t, checkRetired(rootFS(), retired, identifiers, today()))
}

func TestWordsNoDaemonLineWritten(t *testing.T) { expectNone(t, checkLines(rootFS())) }

func TestWordsCatalogueCopyAgrees(t *testing.T) {
	catalogue := os.Getenv("MESH_CATALOG_DIR")
	if catalogue == "" {
		t.Skip("NOT COMPARED: MESH_CATALOG_DIR is not set, so the catalogue's copy of the list was not read")
	}
	retired, _, _ := parseGlossary(readFile(rootFS(), glossaryFile))
	expectNone(t, checkCopy(catalogue, retired))
}

// The checks themselves, against broken trees (H5a: the glossary).

const glossaryFixture = `# Glossary

- **control plane** — the retired one's replacement is below.
  *Not:* ~~control plane~~, ~~overlay~~ (hq), ~~alert~~ (tools), ~~a / b~~
- **controller** — decides.
  *Not:* ~~control plane~~
- **Controller** — again.
- *Identifier until renamed:* ` + "`mesh-host`, `nox-old`" + ` — the repository
`

func TestGlossaryReadsNotLinesScopesIdentifiersAndHeads(t *testing.T) {
	retired, identifiers, heads := parseGlossary(glossaryFixture)
	want := []retiredWord{{"control plane", "all"}, {"overlay", "hq"}, {"alert", "tools"}, {"a", "all"}, {"b", "all"}, {"control plane", "all"}}
	if fmt.Sprint(retired) != fmt.Sprint(want) {
		t.Errorf("retired = %v, want %v", retired, want)
	}
	if fmt.Sprint(identifiers) != "[mesh-host nox-old]" {
		t.Errorf("identifiers = %v", identifiers)
	}
	if fmt.Sprint(heads) != "[control plane controller Controller]" {
		t.Errorf("heads = %v", heads)
	}
	got := checkUnique(retired, heads)
	expectProblem(t, got, `"Controller" heads two entries`)
	expectProblem(t, got, `"control plane" is a head word and also retired`)
}

func TestToolsListHoldsTheWordsOfScopeAllAndTools(t *testing.T) {
	retired, _, _ := parseGlossary(glossaryFixture)
	if got := fmt.Sprint(toolsList(retired)); got != "[a alert b control plane]" {
		t.Errorf("toolsList = %s", got)
	}
}

// H5b: prose blanking and matching.

func TestProseBlanksWhatIsNotRunningProse(t *testing.T) {
	text := "---\nfm: overlay\n---\n" +
		"bare overlay one\n" +
		"```\noverlay in a block\n```\n" +
		"span `overlay` x\n" +
		"> quoted overlay\n" +
		"say \"overlay\" and “overlay” and ‘overlay’\n" +
		"~~overlay~~ struck\n" +
		"[link](overlay.md)\n" +
		"<!-- overlay\nover lines -->\n" +
		"bare overlay two\n"
	got := prose(text, false)
	if strings.Count(got, "overlay") != 2 {
		t.Errorf("only the two bare uses stay: %q", got)
	}
	if strings.Count(got, "\n") != strings.Count(text, "\n") || len(got) != len(text) {
		t.Error("blanking keeps offsets and line numbers")
	}
}

func TestProseOfTheGlossaryBlanksNotAndIdentifierLines(t *testing.T) {
	got := prose("- **x** — y\n  *Not:* control plane, plain\n- *Identifier until renamed:* mesh-host\nthe control plane\n", true)
	if strings.Count(got, "control plane") != 1 || strings.Contains(got, "mesh-host") {
		t.Errorf("only the running use stays: %q", got)
	}
}

func TestWordMatchesWholeWordsPluralsAndLineBreaks(t *testing.T) {
	rx := wordRegexp("control plane")
	count := func(s string) int { return len(findBounded(rx, s)) }
	for s, want := range map[string]int{
		"the control plane runs":           1,
		"Control Planes":                   1,
		"control-plane and control\nplane": 2,
		"uncontrol plane":                  0,
		"control planet":                   0,
		"control plane-x":                  0,
		"x-control plane":                  0,
		"control planexs":                  0,
	} {
		if got := count(s); got != want {
			t.Errorf("%q: %d matches, want %d", s, got, want)
		}
	}
}

func TestRetiredCatchesAWordInProseAndNamesDocumentAndLine(t *testing.T) {
	retired := []retiredWord{{"control plane", "all"}, {"overlay", "hq"}, {"alert", "tools"}}
	broken := mapOf(map[string]string{
		"AGENTS.md":               "fine\nthe control plane here\n",
		"03-DESIGN/01-to-be/a.md": "an overlay and \"a control plane quoted\" and `overlay` alert\n",
		"README.md":               "mesh-host runs; `mesh-host` too\n",
	})
	got := checkRetired(broken, retired, []string{"mesh-host"}, "2026-10-23")
	expectProblem(t, got, `AGENTS.md:2: "control plane" is retired`)
	expectProblem(t, got, `03-DESIGN/01-to-be/a.md:1: "overlay" is retired`)
	expectProblem(t, got, `README.md:1: "mesh-host" is an identifier, allowed only in a code span`)
	if len(got) != 3 {
		t.Errorf("a quotation, a code span and a word of scope tools are not problems: %q", got)
	}
}

func TestIssuesAreHeldToTheRuleFromItsDay(t *testing.T) {
	retired := []retiredWord{{"overlay", "all"}}
	fsys := mapOf(map[string]string{
		"04-ISSUES/1-old/00-report.md":    "---\nopened: 2026-10-06\n---\noverlay\n",
		"04-ISSUES/2-new/00-report.md":    "---\nopened: 2026-10-07\n---\nfine\n",
		"04-ISSUES/2-new/01-notes.md":     "an overlay\n",
		"04-ISSUES/3-nodate/00-report.md": "overlay\n",
	})
	got := checkRetired(fsys, retired, nil, "2026-10-23")
	expectProblem(t, got, "04-ISSUES/2-new/01-notes.md:1")
	if len(got) != 1 {
		t.Errorf("only the issue opened from 2026-10-07 on is read: %q", got)
	}
}

// H5c: allowances, with an injected clock.

const allowedFixture = `# Words allowed

| Document | Until | Why |
|---|---|---|
| ` + "`a.md`" + ` | 2026-12-01 | quotes what was |
| ` + "`b.md`" + ` | 2026-10-01 | ran out |
| ` + "`c.md`" + ` | soon | no date |
| ` + "`d.md`" + ` | 2026-12-01 | |
`

func TestAllowedReadsRowsAndTheInjectedClock(t *testing.T) {
	allowed, problems := parseAllowed(allowedFixture, "2026-10-23")
	if _, ok := allowed["a.md"]; !ok || len(allowed) != 2 {
		t.Errorf("a.md and d.md are in date: %v", allowed)
	}
	expectProblem(t, problems, "the allowance for b.md ran out on 2026-10-01")
	expectProblem(t, problems, "the allowance for c.md has no date")
	expectProblem(t, problems, "the allowance for d.md gives no reason")
	// The same text on an earlier day: b.md is still in date.
	if early, _ := parseAllowed(allowedFixture, "2026-09-30"); len(early) != 3 {
		t.Errorf("on 2026-09-30 a, b and d are in date: %v", early)
	}
}

func TestAllowanceHoldsAWordBackUntilItsDateAndShrinks(t *testing.T) {
	retired := []retiredWord{{"overlay", "all"}}
	allowedRow := "| `AGENTS.md` | 2026-12-01 | quotes what was |\n"
	tree := func(agents, allowed string) map[string]string {
		return map[string]string{"AGENTS.md": agents, allowedFile: allowed}
	}
	expectNone(t, checkRetired(mapOf(tree("an overlay\n", allowedRow)), retired, nil, "2026-10-23"))
	expectProblem(t, checkRetired(mapOf(tree("an overlay\n", allowedRow)), retired, nil, "2026-12-02"), "ran out on 2026-12-01")
	expectProblem(t, checkRetired(mapOf(tree("clean\n", allowedRow)), retired, nil, "2026-10-23"), "AGENTS.md no longer uses a retired word")
	expectProblem(t, checkRetired(mapOf(tree("an overlay\n", "")), retired, nil, "2026-10-23"), `AGENTS.md:1: "overlay" is retired`)
}

// H5d: the daemons' lines and the catalogue comparison.

func TestLinesCatchesADaemonsLineButNotProse(t *testing.T) {
	fsys := mapOf(map[string]string{
		"AGENTS.md": "the mesh-controller module is prose\n" +
			"run `mesh-controller module check x` now\n" +
			"or:\n```\n$ mesh-controller push\n```\n" +
			"a quotation \"mesh-controller status\" stays\n" +
			"> mesh-controller doctor in a block quote\n" +
			"a mesh-controller pushed is another word\n",
		"04-ISSUES/1/00-report.md": "---\nopened: 2026-10-08\n---\nmesh-host apply\n",
		"04-ISSUES/2/00-report.md": "---\nopened: 2026-10-09\n---\nmesh-host apply\n",
	})
	got := checkLines(fsys)
	expectProblem(t, got, "AGENTS.md:2: `mesh-controller module` is a daemon's line")
	expectProblem(t, got, "AGENTS.md:5: `mesh-controller push` is a daemon's line")
	expectProblem(t, got, "04-ISSUES/2/00-report.md:4: `mesh-host apply`")
	if len(got) != 3 {
		t.Errorf("prose, quotations, block quotes and issues before 2026-10-09 are not problems: %q", got)
	}
}

func TestLinesListNamesEachLineOnce(t *testing.T) {
	list := linesList()
	seen := map[string]bool{}
	for _, l := range list {
		if seen[l] {
			t.Errorf("%q listed twice", l)
		}
		seen[l] = true
	}
	if !seen["mesh-controller push"] || !seen["mesh-controller module …"] || !seen["nox-mesh-host hand-over"] {
		t.Errorf("the list lacks a known line: %v", list[:5])
	}
}

func TestCatalogueCopyDifferenceIsCaughtAndNamesTheList(t *testing.T) {
	retired := []retiredWord{{"overlay", "all"}, {"alert", "tools"}, {"hq only", "hq"}}
	dir := t.TempDir()
	write := func(name, content string) {
		if err := os.WriteFile(path.Join(dir, name), []byte(content), 0o644); err != nil {
			t.Fatal(err)
		}
	}
	write("retired-words", "# copy\nalert\noverlay\n")
	write("retired-lines", strings.Join(linesList(), "\n")+"\n")
	expectNone(t, checkCopy(dir, retired))

	write("retired-words", "alert\n")
	write("retired-lines", "mesh-controller push\n")
	got := checkCopy(dir, retired)
	expectProblem(t, got, "retired-words differs from the glossary: it should list alert, overlay")
	expectProblem(t, got, "retired-lines differs from this check's list")
	expectProblem(t, checkCopy(t.TempDir(), retired), "cannot be read")
}

func mapOf(files map[string]string) fs.FS {
	m := fstest.MapFS{}
	for k, v := range files {
		m[k] = doc(v)
	}
	return m
}