package busstate

import (
	"bufio"
	"encoding/json"
	"io"
	"testing"
	"time"

	stdio "git.novox.be/novox/mesh-sdk/go"
	"git.novox.be/novox/mesh-sdk/go/buscalls"
)

// A bundle keeps objects in its own object store through the runtime (ADR 0595 §2, §9; A3's request for distribution's
// incoming): each call is the runtime's method of buscalls, naming the store by its local name, and answers as the
// runtime answered; a method that is no bus-state call is refused before the runtime is asked.
func TestABundleKeepsObjectsThroughTheRuntime(t *testing.T) {
	t.Setenv(stdio.ServedAs, "distribution")
	inR, inW := io.Pipe()
	outR, outW := io.Pipe()
	type result struct {
		what string
		err  error
		got  any
	}
	results := make(chan result, 8)
	go func() {
		_ = stdio.ServeOn("", []stdio.Tool{{Name: "keep", Run: func(map[string]any) (any, error) {
			go func() {
				in := ObjectsOf("incoming")
				info, err := in.Put("t1.part0", []byte("hello"), "a part")
				results <- result{"put", err, info.Digest}
				data, err := in.Get("t1.part0")
				results <- result{"get", err, string(data.Data)}
				list, err := in.List()
				results <- result{"list", err, len(list)}
				results <- result{"delete", in.Delete("t1.part0"), nil}
				fill, err := in.Fill()
				results <- result{"fill", err, fill.MaxBytes}
				_, err = stdio.BusState("mesh/state.get", nil)
				results <- result{"refused", err, nil}
			}()
			return "started", nil
		}}}, inR, outW)
	}()
	lines := bufio.NewScanner(outR)
	next := func() map[string]any {
		done := make(chan map[string]any, 1)
		go func() {
			if lines.Scan() {
				var m map[string]any
				_ = json.Unmarshal(lines.Bytes(), &m)
				done <- m
			}
		}()
		select {
		case m := <-done:
			return m
		case <-time.After(3 * time.Second):
			t.Fatal("the bundle said nothing")
			return nil
		}
	}
	send := func(m map[string]any) { b, _ := json.Marshal(m); _, _ = inW.Write(append(b, '\n')) }
	send(map[string]any{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": map[string]any{"name": "keep"}})
	answers := map[string]any{
		buscalls.ObjectsPut:    buscalls.ObjectInfo{Name: "t1.part0", Size: 5, Digest: "SHA-256=x"},
		buscalls.ObjectsGet:    buscalls.ObjectData{Info: buscalls.ObjectInfo{Name: "t1.part0"}, Data: []byte("hello")},
		buscalls.ObjectsList:   buscalls.ObjectsListed{Objects: []buscalls.ObjectInfo{{Name: "t1.part0"}}},
		buscalls.ObjectsDelete: buscalls.Done{},
		buscalls.ObjectsInfo:   buscalls.Fill{Count: 0, MaxBytes: 20 << 30},
	}
	asked := map[string]map[string]any{}
	for len(asked) < len(answers) {
		m := next()
		method, _ := m["method"].(string)
		if method == "" {
			continue // the tool's own answer
		}
		p, _ := m["params"].(map[string]any)
		asked[method] = p
		send(map[string]any{"jsonrpc": "2.0", "id": m["id"], "result": answers[method]})
	}
	want := map[string]any{"put": "SHA-256=x", "get": "hello", "list": 1, "delete": nil, "fill": uint64(20 << 30)}
	for range 5 {
		r := <-results
		if r.err != nil || r.got != want[r.what] {
			t.Errorf("%s answered %v, %v; want %v", r.what, r.got, r.err, want[r.what])
		}
	}
	if r := <-results; r.err == nil {
		t.Error("a call that is not on the bundle's bus state was asked of the runtime")
	}
	for method, p := range asked {
		if p["objects"] != "incoming" {
			t.Errorf("%s named the store %v, not its local name", method, p["objects"])
		}
	}
	if p := asked[buscalls.ObjectsPut]; p["name"] != "t1.part0" || p["data"] != "aGVsbG8=" || p["description"] != "a part" {
		t.Errorf("put asked %v", p)
	}
}