package announce

import (
	"encoding/json"
	"fmt"
	"strings"
	"testing"
)

// What a machine serves fits the bus's largest message (1 MiB) with room to spare at several hundred
// tools: a module's tool is announced without its schema, which made a machine with ~200 tools outgrow it
// and vanish from discovery (2026-10-04). A seat's verb keeps its schema.
func TestAMachinesAnnouncementFitsTheBusAtSeveralHundredTools(t *testing.T) {
	schema := json.RawMessage(`{"type":"object","properties":{` + strings.Repeat(`"field_with_a_long_name":{"type":"string","description":"a description of what this argument means, long enough to matter"},`, 12) + `"last":{"type":"string"}}}`)
	description := strings.Repeat("A tool that does something useful, described at the length the catalogue's tools are. ", 3)
	var endpoints []Endpoint
	for i := 0; i < 400; i++ {
		for _, subject := range []string{fmt.Sprintf("mesh.mod.m%d.tool.t", i), fmt.Sprintf("mesh.mod.m%d.tool.t.laptop", i)} {
			endpoints = append(endpoints, Endpoint{Kind: KindTool, Module: fmt.Sprintf("m%d", i), Tool: "t", Node: "laptop",
				Description: description, Schema: schema, Subject: subject})
		}
	}
	endpoints = append(endpoints, Endpoint{Kind: KindSeat, Module: "m0", Tool: "verb", Seat: "a-seat", Scope: "mesh",
		Description: "a verb", Schema: schema, Subject: "mesh.seat.a-seat.tool.verb"})
	body, err := json.Marshal(Info(Service{Name: "node-tools", ID: "laptop"}, endpoints))
	if err != nil {
		t.Fatal(err)
	}
	if len(body) > 1<<20 {
		t.Fatalf("400 tools announce %d bytes, beyond the bus's 1 MiB", len(body))
	}
	t.Logf("400 tools on two subjects each announce %d bytes", len(body))
	back := Endpoints(Info(Service{Name: "node-tools", ID: "laptop"}, endpoints))
	if len(back[0].Schema) != 0 {
		t.Fatalf("a module's tool still carries its schema: %s", back[0].Schema)
	}
	if seat := back[len(back)-1]; !strings.Contains(string(seat.Schema), "field_with_a_long_name") {
		t.Fatalf("a seat's verb lost its schema: %s", seat.Schema)
	}
	withSchemas := 0
	for range endpoints {
		withSchemas += len(schema) * 2 // escaped inside a string
	}
	t.Logf("with every schema it would have been over %d bytes", len(body)+withSchemas)
}

func TestFirstLineShortensADescription(t *testing.T) {
	if got := firstLine("One thing. And more after it."); got != "One thing." {
		t.Fatalf("%q", got)
	}
	if got := firstLine(strings.Repeat("x", 300)); len(got) != 160 {
		t.Fatalf("%d", len(got))
	}
}