package main

import (
	"encoding/json"
	"strings"
	"testing"
	"time"

	"github.com/novox/mesh-controller/internal/inventory"
	"github.com/novox/mesh-controller/internal/link"
)

// The assignment generation a declaration was composed from (novox/hq issue 234).

func bodyKeys(t *testing.T, s sendable) map[string]any {
	t.Helper()
	raw, err := s.Body()
	if err != nil {
		t.Fatal(err)
	}
	var keys map[string]any
	if err := json.Unmarshal(raw, &keys); err != nil {
		t.Fatal(err)
	}
	return keys
}

// **The generation goes on the wire only to a machine whose node-engine said it reads one**: an older
// node-engine decodes strictly and refuses an unknown key, whole. No put-back mark is ever sent: a gate
// composes its put-back afresh, with the generation as it stands.
func TestTheGenerationIsSentOnlyToAMachineThatReadsOne(t *testing.T) {
	resources := []map[string]any{{"id": "a", "type": "file", "path": "/etc/a", "content": "x\n"}}
	reads := order{sequence: 12, epoch: 57, generation: 40, readsGeneration: true, acting: 57}
	var told sendable
	told.Resources = resources
	reads.stamp(&told)
	keys := bodyKeys(t, told)
	if keys["generation"] != float64(40) || keys["sequence"] != float64(12) {
		t.Fatalf("a machine that reads a generation was sent %v", keys)
	}
	if _, there := keys["put_back"]; there {
		t.Fatalf("a put-back mark was sent: %v", keys)
	}
	if told.composedFrom != 40 || told.actingEpoch != 57 {
		t.Errorf("the send does not keep what it was composed from for its record: %+v", told)
	}

	older := order{sequence: 12, epoch: 57, generation: 40, readsGeneration: false, acting: 57}
	var untold sendable
	untold.Resources = resources
	older.stamp(&untold)
	if _, there := bodyKeys(t, untold)["generation"]; there {
		t.Fatal("a machine whose node-engine never said it reads a generation was sent one")
	}
	if untold.composedFrom != 40 {
		t.Errorf("the generation it was composed from is recorded whether or not it was sent: %+v", untold)
	}
}

// **The sender is named**: the caller of the seat call when there is one, else the shell's account, and the
// process and build that composed it.
func TestASendNamesItsSender(t *testing.T) {
	said := senderOf("g14.node-tools, through the mesh-controller seat")
	if !strings.Contains(said, "g14.node-tools") || !strings.Contains(said, "pid ") || !strings.Contains(said, "build ") {
		t.Fatalf("the sender reads %q", said)
	}
}

// refusedSend is a send a machine refused for its generation at a moment.
func refusedSend(at time.Time) inventory.Send {
	return inventory.Send{NodeName: "anchor", Sequence: 12, Epoch: 57, Generation: 38, RefusedApplied: 40,
		Sender:  "a one-shot push by jochen at a shell on anchor (pid 4242 on anchor, build 2026.10.11)",
		Modules: []string{"docker"}, SentAt: at.Add(-time.Second), RefusedAt: &at, Recorded: true}
}

// **A refused send is raised naming its sender** (novox/hq issue 234): who sent it, from which generation,
// against which the machine applied, and its sequence — the facts that took a morning to look for.
func TestARefusedSendIsRaisedNamingItsSender(t *testing.T) {
	now := time.Date(2026, 10, 11, 12, 0, 0, 0, time.UTC)
	f := calm(now)
	f.refusedSends = []inventory.Send{refusedSend(now.Add(-time.Minute))}
	got := watchGenerationRefusals(f)
	if len(got) != 1 {
		t.Fatalf("%+v", got)
	}
	o := got[0]
	if o.Key() != "machine.anchor.older-generation" || o.Machine != "anchor" {
		t.Errorf("raised as %s about %q", o.Key(), o.Machine)
	}
	for _, want := range []string{"a one-shot push by jochen", "generation 38", "generation 40", "sequence 12"} {
		if !strings.Contains(o.Summary, want) {
			t.Errorf("the summary does not say %q: %s", want, o.Summary)
		}
	}
	if o.Headline == "" || o.Explanation == "" || o.Resolved == "" {
		t.Errorf("the condition is not worded for the operator: %+v", o)
	}
}

// **A refusal of a send the mesh has no record of is raised too, its sender said to be unknown** — never
// only a line on stderr.
func TestARefusalOfAnUnrecordedSendIsRaisedSayingTheSenderIsUnknown(t *testing.T) {
	now := time.Date(2026, 10, 11, 12, 0, 0, 0, time.UTC)
	f := calm(now)
	s := refusedSend(now.Add(-time.Minute))
	s.Recorded, s.Sender, s.Modules = false, "a sender the mesh has no record of (no send of this sequence was recorded)", nil
	f.refusedSends = []inventory.Send{s}
	got := watchGenerationRefusals(f)
	if len(got) != 1 || !strings.Contains(got[0].Summary, "no record of") {
		t.Fatalf("an unattributed refusal was not raised as one: %+v", got)
	}
}

// **When the refusal showed the mesh's counter behind the machine, the condition asks for a push** — it was
// raised, and nothing has sent the machine its declaration since — and does not say there is nothing to do.
func TestACounterBehindTheMachineAsksForAPush(t *testing.T) {
	now := time.Date(2026, 10, 11, 12, 0, 0, 0, time.UTC)
	f := calm(now)
	s := refusedSend(now.Add(-time.Minute))
	s.Generation, s.RefusedApplied, s.CounterRaisedTo = 12, 40, 41
	f.refusedSends = []inventory.Send{s}
	got := watchGenerationRefusals(f)
	if len(got) != 1 {
		t.Fatalf("%+v", got)
	}
	if !strings.Contains(got[0].Summary, "`push anchor`") || !strings.Contains(got[0].Explanation, "push anchor") ||
		strings.Contains(got[0].Explanation, "Nothing for you to do") {
		t.Errorf("a counter behind the machine does not ask for a push: %s / %s", got[0].Summary, got[0].Explanation)
	}
}

// **Only a refusal of the counter as it stands is the counter behind**: a stale sender's generation is below
// it, and the counter is left alone for that.
func TestOnlyARefusalOfTheCounterAsItStandsRaisesIt(t *testing.T) {
	for _, c := range []struct {
		refused, applied, now int64
		behind                bool
	}{
		{refused: 12, applied: 40, now: 12, behind: true},  // the store was put back: the mesh says 12, the machine had 40
		{refused: 38, applied: 40, now: 41, behind: false}, // a stale sender: the counter is already past
		{refused: 38, applied: 40, now: 40, behind: false}, // a stale sender: the counter is where the machine is
	} {
		r := link.GenerationRefusal{Generation: c.refused, Applied: c.applied}
		if got := counterBehind(r, c.now); got != c.behind {
			t.Errorf("refused %d, applied %d, counter %d: behind %v, want %v", c.refused, c.applied, c.now, got, c.behind)
		}
	}
}