package main

import (
	"testing"

	"github.com/kami/maven/internal/router"
)

// The floor, and it is the reason a destination is safe to add at all: a box
// whose model is down names nothing, and naming nothing has to walk the chain
// the way it walked before the field existed.
func TestNoDestinationWalksTheWholeChain(t *testing.T) {
	walk, skipped := queryWalk(router.SourceUnknown, false)
	if len(skipped) != 0 {
		t.Errorf("skipped %d sources with no destination named, want none", len(skipped))
	}
	if len(walk) != len(querySources) {
		t.Fatalf("walk has %d sources, want the whole table of %d", len(walk), len(querySources))
	}
	for i := range walk {
		if walk[i].name != querySources[i].name {
			t.Fatalf("position %d is %q, want %q", i, walk[i].name, querySources[i].name)
		}
	}
}

// The 2026-08-07 defects, one per line. Each is a source that decides by seed
// similarity claiming a turn that was never its own, and then answering it
// because it has no lookup that could come back empty.
func TestANamedDestinationSilencesTheOtherGuessers(t *testing.T) {
	cases := []struct {
		dest      router.Source
		utterance string
		silenced  string
		anchored  bool // a stage 0 grammar named the destination
	}{
		{router.SourceWorld, "что такое TCP?", "weather", true},
		{router.SourceWorld, "сколько будет 17 на 23?", "weather", true},
		{router.SourceWorld, "кто такой Линус Торвальдс?", "personal", true},
		{router.SourceRecall, "какой у меня любимый язык?", "feeds", false},
		{router.SourceCalendar, "что в календаре на завтра?", "weather", true},
	}
	for _, c := range cases {
		walk, skipped := queryWalk(c.dest, c.anchored)
		if inWalk(walk, c.silenced) {
			t.Errorf("%q named %q: %q is still asked", c.utterance, c.dest, c.silenced)
		}
		if !inWalk(skipped, c.silenced) {
			t.Errorf("%q named %q: %q is missing from the record of who was skipped",
				c.utterance, c.dest, c.silenced)
		}
	}
}

// Naming the world must not send the turn outside. His notes, his facts and the
// boundary in front of them are the invariant CLAUDE.md states as "the owner's
// data first, then the world", and a destination a model wrote must not be able
// to reverse it.
func TestNamingTheWorldStillReadsHisDataFirst(t *testing.T) {
	walk, _ := queryWalk(router.SourceWorld, true)
	for _, look := range []string{"fact-by-key", "embed", "memory", "notes"} {
		if !inWalk(walk, look) {
			t.Errorf("%q was dropped; only the sources that guess may be dropped", look)
		}
	}
	if posOf(walk, "notes") > posOf(walk, "search") {
		t.Error("search is asked before his notes are")
	}
	if posOf(walk, "search") < 0 {
		t.Fatal("search is not in the walk at all")
	}
}

// The boundary belongs to his data, so naming recall keeps it. That is what
// makes "какой у меня любимый язык?" answer "не нашла у тебя такой записи"
// rather than reaching SearXNG once nothing local had it.
func TestNamingRecallKeepsTheBoundary(t *testing.T) {
	walk, _ := queryWalk(router.SourceRecall, true)
	if !inWalk(walk, "personal") {
		t.Fatal("the personal boundary was skipped on a turn named for his own data")
	}
	if posOf(walk, "personal") > posOf(walk, "search") {
		t.Error("the boundary no longer sits in front of the world")
	}
}

// The owner's call of 2026-08-09 (V-666): only a stage 0 grammar may take the
// personal boundary off a turn. The routing heads and the resident model both
// name a destination by inference, and an inferred SourceWorld would send a
// question about him upstream. Every other guesser still goes.
func TestOnlyAGrammarMayDropTheBoundary(t *testing.T) {
	walk, skipped := queryWalk(router.SourceWorld, false)
	if !inWalk(walk, "personal") {
		t.Error("an inferred destination took the boundary off the turn")
	}
	if !inWalk(skipped, "weather") {
		t.Error("weather is still asked; the rule covers the boundary alone")
	}
	if posOf(walk, "personal") > posOf(walk, "search") {
		t.Error("the boundary no longer sits in front of the world")
	}
	if anchored, _ := queryWalk(router.SourceWorld, true); inWalk(anchored, "personal") {
		t.Error(`a grammar named the world and the boundary stayed: ` +
			`"кто такой Линус Торвальдс?" is answered "не нашла у тебя такой записи" again`)
	}
}

// Whatever the destination, the walk is a subsequence of the table. Every
// comment on that table argues an order between two sources, and none of those
// reasons is about this field.
func TestTheWalkNeverReordersTheTable(t *testing.T) {
	for _, dest := range append([]router.Source{router.SourceUnknown}, router.Sources...) {
		walk, skipped := queryWalk(dest, true)
		if len(walk)+len(skipped) != len(querySources) {
			t.Errorf("%q: %d walked + %d skipped, want %d", dest, len(walk), len(skipped), len(querySources))
		}
		last := -1
		for _, s := range walk {
			at := posOf(querySources, s.name)
			if at <= last {
				t.Errorf("%q: %q is out of table order", dest, s.name)
			}
			last = at
		}
	}
}

func inWalk(list []querySource, name string) bool { return posOf(list, name) >= 0 }

func posOf(list []querySource, name string) int {
	for i, s := range list {
		if s.name == name {
			return i
		}
	}
	return -1
}