package main

import (
	"context"
	"strings"
	"testing"
	"time"

	"github.com/novox/mesh-controller/internal/broker"
	"github.com/novox/mesh-controller/internal/conditions"
	"github.com/novox/mesh-controller/internal/link"
	"github.com/novox/mesh-controller/internal/testbus"
)

// The serving controller's bus, with the mesh's streams, for the verb to read and act on.
func servingDeadLetters(t *testing.T) *broker.JetStream {
	t.Helper()
	js, err := broker.Dial(testbus.URL(t))
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(js.Close)
	if err := broker.AssertMeshStreams(js); err != nil {
		t.Fatal(err)
	}
	if err := js.EnsureControllerBuckets(); err != nil {
		t.Fatal(err)
	}
	before := servingBus.Load()
	servingBus.Store(js)
	t.Cleanup(func() { servingBus.Store(before) })
	return js
}

func askDeadLetters(t *testing.T, args map[string]any) (any, error) {
	t.Helper()
	a, err := readArguments("dead-letters", args)
	if err != nil {
		return nil, err
	}
	return deadLettersAnswer(context.Background(), a)
}

func TestDeadLettersListsDropsAndRecordsWhy(t *testing.T) {
	js := servingDeadLetters(t)
	if _, err := js.Context().Publish("mesh.mod.gitea.event.pull.merged", []byte(`{"n":1}`)); err != nil {
		t.Fatal(err)
	}
	d, err := link.KeepDeadLetter(js.Context(), []byte(`{"stream":"EVENTS","consumer":"media_sonarr","stream_seq":1,"deliveries":5}`))
	if err != nil {
		t.Fatal(err)
	}

	answer, err := askDeadLetters(t, map[string]any{})
	if err != nil {
		t.Fatal(err)
	}
	listed := answer.(map[string]any)
	if listed["held"] != 1 || len(listed["dead_letters"].([]link.DeadLetter)) != 1 {
		t.Fatalf("listed %v", listed)
	}

	// Refused before anything is done: an act without why, an argument the shape passes over, both acts.
	for _, args := range []map[string]any{
		{"drop": "1"},
		{"drop": "1", "why": "x", "limit": "3"},
		{"drop": "1", "deliver": "1", "why": "x"},
		{"why": "x"},
		{"id": "nought"},
	} {
		if _, err := askDeadLetters(t, args); err == nil {
			t.Errorf("%v was done", args)
		}
	}
	if _, total, _ := link.DeadLetters(js.Context(), "", 0); total != 1 {
		t.Fatalf("a refused call changed what is kept: %d left", total)
	}

	done, err := askDeadLetters(t, map[string]any{"drop": "1", "why": "the media server took the download in by hand"})
	if err != nil {
		t.Fatal(err)
	}
	if said := done.(map[string]any); said["recorded"] == nil || !strings.Contains(said["done"].(string), "dropped") {
		t.Fatalf("answered %v", said)
	}
	acts, err := link.HandActs(context.Background(), js.Conn(), time.Now().Add(-time.Minute))
	if err != nil || len(acts) != 1 || acts[0].Verb != "dead-letters drop" || acts[0].Cause != causeDeadLetter ||
		!strings.Contains(acts[0].Condition, "media_sonarr") {
		t.Fatalf("recorded %+v (%v)", acts, err)
	}
	if !personsDecision(acts[0]) {
		t.Error("dropping a dead letter is counted as a repair, so S15 would want a healer for it")
	}
	if _, err := askDeadLetters(t, map[string]any{"id": "1"}); err == nil {
		t.Errorf("dead letter %d is still answered after it was dropped", d.ID)
	}
}

// Open while DEAD_LETTERS holds a message for the consumer, in words the operator reads in one pass:
// what is held, and where to act.
func TestAConsumersDeadLettersAreSaidUntilActedOn(t *testing.T) {
	f := &signalFacts{now: time.Now(), deadLetters: map[string]int{"EVENTS.media_sonarr": 4, "EVENTS.controller": 1}}
	found := watchDeadLetters(f)
	if len(found) != 2 {
		t.Fatalf("said %d conditions", len(found))
	}
	for _, o := range found {
		if o.Kind != "max-deliveries" || o.Severity != conditions.Warning || o.Needs == "" {
			t.Errorf("%+v", o)
		}
		if why, ok := conditions.PlainWords(conditions.Words{Headline: o.Headline, Needs: o.Needs,
			Explanation: o.Explanation, Resolved: o.Resolved}, "media"); !ok {
			t.Errorf("%q is not plain: %s", o.Headline, why)
		}
		if !strings.Contains(o.Needs, "mesh MCP server") {
			t.Errorf("does not say where to act: %q", o.Needs)
		}
	}
	sonarr := found[1]
	if sonarr.ID != "EVENTS.media_sonarr" || sonarr.Machine != "media" ||
		sonarr.Headline != "Sonarr on media could not handle 4 messages" ||
		!strings.Contains(sonarr.Summary, "DEAD_LETTERS") {
		t.Errorf("%+v", sonarr)
	}
	if found[0].Headline != "The controller could not handle a message" {
		t.Errorf("%q", found[0].Headline)
	}
	// None held, none said: it clears when they are delivered again or dropped.
	if left := watchDeadLetters(&signalFacts{now: time.Now()}); len(left) != 0 {
		t.Fatalf("%v", left)
	}
}