package main

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

// ADR 0329 §10, §12: derived from every desktop node's profile, laid out per layer, and proposed one layer at a
// time, carrying the layer as it stands.

// derivingMesh is two desktop nodes, g14 (this one, f) and shanks (f2), and a server that holds no Betterbird, as the
// controller answers them; layers are the controller's layers, open the proposals that wait.
type derivingMesh struct {
	t        *testing.T
	shanks   *fake
	layers   map[string]map[string]any
	open     bool
	proposed []map[string]any
	asked    []string
	asleep   bool
	// garbled answers the layer in words that are not its JSON.
	garbled bool
}

func (d *derivingMesh) ask(key string, body any) (json.RawMessage, error) {
	d.asked = append(d.asked, key)
	args, _ := body.(map[string]any)
	answer := func(ok bool, text string) (json.RawMessage, error) {
		b, _ := json.Marshal(map[string]any{"ok": ok, "output": text})
		return b, nil
	}
	switch {
	case key == "seat:mesh-controller.nodes":
		return answer(true, `[{"name": "g14"}, {"name": "novox"}, {"name": "shanks"}]`)
	case key == "seat:mesh-controller.node":
		if args["node"] == "novox" {
			return answer(true, "novox\n  assigned: postgres, nats\n")
		}
		return answer(true, fmt.Sprintf("%s\n  last heard from   here\n  assigned: adwaita, betterbird, dunst\n", args["node"]))
	case key == "betterbird.betterbird_derive@shanks":
		if d.asleep {
			return nil, errors.New("nats: no responders available for request")
		}
		here, err := d.shanks.deriveHere(stringsOf(args["kinds"]))
		if err != nil {
			d.t.Fatal(err)
		}
		text, _ := json.Marshal(credentialChecked(DeriveAnswer{Here: &here}))
		return json.Marshal(map[string]any{"content": []any{map[string]any{"type": "text", "text": string(text)}}})
	case key == "seat:mesh-controller.settings" && args["proposals"] == "true":
		if d.open {
			return answer(true, "sab12  set betterbird on the whole mesh  (accounts, identities)\n    by g14.node-tools at 2026-10-13 01:00; fingerprint ab12\n    waiting for the operator until 2026-10-14 01:00\n"+
				"scd34  set mounts on shanks  (sources)\n    by g14.node-tools at 2026-10-11 00:05; fingerprint dd0b\n    chosen: done\n")
		}
		return answer(true, "scd34  set mounts on shanks  (sources)\n    by g14.node-tools; fingerprint dd0b\n    chosen: done\n")
	case key == "seat:mesh-controller.settings" && args["propose"] == "true":
		d.proposed = append(d.proposed, args)
		return answer(true, "proposal sab12: Set the settings of betterbird?\n  fingerprint ab12")
	case key == "seat:mesh-controller.settings":
		node, _ := args["node"].(string)
		if d.garbled {
			return answer(true, "Settings of betterbird on "+node+":\n  accounts = {…}\n")
		}
		layer := d.layers[node]
		if layer == nil {
			where := node
			if where == "" {
				where = "the whole mesh"
			}
			return answer(true, "betterbird on "+where+": no layer — the module's definition says\nbetterbird on "+where+", every value")
		}
		b, _ := json.MarshalIndent(layer, "", "  ")
		return answer(true, string(b)+"\n  approved by the operator\nbetterbird on the whole mesh, every value and where it comes from:\n")
	}
	d.t.Fatalf("asked %s %v", key, body)
	return nil, nil
}

func stringsOf(v any) []string {
	switch x := v.(type) {
	case []string:
		return x
	case []any:
		var out []string
		for _, s := range x {
			out = append(out, s.(string))
		}
		return out
	}
	return nil
}

func TestDeriveLaysEachEntryOutPerLayerAndProposesOneLayerAtATime(t *testing.T) {
	f := newFake(t)
	f.profileWithAccounts()
	f.profileWithConfiguration()
	f.write(profileDir+"/prefs.js", f.read(profileDir+"/prefs.js")+
		`user_pref("calendar.registry.c6.type", "caldav");`+"\n"+
		`user_pref("calendar.registry.c6.uri", "https://other:hunter2@dav.example.org/cal/x/");`+"\n"+
		`user_pref("calendar.registry.c6.name", "Old");`+"\n")
	f.declareAccounts(adoptable)
	links(t, nil)
	f2 := newFake(t)
	f2.profileWithAccounts()
	f2.profileWithConfiguration()
	// shanks holds the same accounts and calendars, another signature, another tag colour and a calendar of its own.
	f2.write(profileDir+"/prefs.js", strings.NewReplacer(`"Regards"`, `"Cheers"`, `"#FF0000"`, `"#CC0000"`).Replace(f2.read(profileDir+"/prefs.js"))+
		`user_pref("calendar.registry.s1.type", "caldav");`+"\n"+
		`user_pref("calendar.registry.s1.uri", "https://dav.example.org/cal/standup/");`+"\n"+
		`user_pref("calendar.registry.s1.name", "Standup");`+"\n")
	f2.declareAccounts(adoptable)
	mesh := &derivingMesh{t: t, shanks: f2, layers: map[string]map[string]any{"": {"accounts": map[string]any{"mail": "as approved"}}}}
	oldNode, oldAsk := nodeName, asker
	t.Cleanup(func() { nodeName, asker = oldNode, oldAsk })
	nodeName = func() string { return "g14" }
	asker = mesh.ask

	a, err := f.Derive(nil, false, false, nil, "")
	if err != nil {
		t.Fatal(err)
	}
	if !reflect.DeepEqual(a.From, []string{"g14", "shanks"}) || len(a.NotHeard) != 0 {
		t.Fatalf("derived from the nodes holding Betterbird: %v %v", a.From, a.NotHeard)
	}
	whole := mustJSON(a)
	mw := a.Layers[meshWide]
	ids, _ := mw[kindIdentities].(map[string]any)
	if mail, _ := ids["mail"].(map[string]any); mail == nil || mustJSON(mail["signature"]) != `["Regards"]` || mail["address"] != nil {
		t.Errorf("an identity on both nodes is mesh-wide with this node's value, the default without its address: %v", ids)
	}
	cals, _ := mw[kindCalendars].(map[string]any)
	if cals["home"] == nil || cals["standup"] != nil {
		t.Errorf("a calendar both hold is mesh-wide, one only shanks holds is not: %v", cals)
	}
	if sh := mustJSON(a.Layers["shanks"]); !strings.Contains(sh, "https://dav.example.org/cal/standup/") {
		t.Errorf("an entry on one node only goes into that node's layer: %s", sh)
	}
	tags, _ := mw[kindTags].(map[string]any)
	if l1, _ := tags["$label1"].(map[string]any); l1 == nil || l1["color"] != "#FF0000" {
		t.Errorf("the tag is mesh-wide with this node's colour: %v", tags)
	}
	diffs := map[string]difference{}
	for _, d := range a.Differences {
		diffs[d.Kind+"/"+d.Entry+"/"+d.Field] = d
	}
	if d := diffs["identities/mail/signature"]; d.Node != "shanks" || mustJSON(d.There) != `["Cheers"]` {
		t.Errorf("the answer lists the field shanks holds differently: %+v", a.Differences)
	}
	if d := diffs["tags/$label1/color"]; d.There != "#CC0000" || d.MeshWide != "#FF0000" {
		t.Errorf("%+v", a.Differences)
	}
	for _, never := range []string{"secret-token", "hunter2", "owl://", `"Work"`} {
		if strings.Contains(mustJSON(a.Layers), never) {
			t.Errorf("no ICS address, credential or Owl calendar is derived: %s in %s", never, mustJSON(a.Layers))
		}
	}
	if !strings.Contains(whole, "Holidays") || !strings.Contains(whole, "‹withheld›") || strings.Contains(mustJSON(credentialChecked(a)), "hunter2") {
		t.Errorf("what is left out is named, an ICS calendar by its name and a password as ‹withheld›: %v", a.NotDerived)
	}
	if len(mesh.proposed) != 0 {
		t.Fatal("without propose nothing is proposed")
	}

	// Propose: the mesh-wide layer first, as it stands with the derived kinds, and the operator's setup of prefs.
	prefs := map[string]any{}
	for n, v := range shippedDefaultsWant {
		prefs[n], _ = prefValue(v)
	}
	a, err = f.Derive(nil, false, true, prefs, "")
	if err != nil {
		t.Fatal(err)
	}
	if len(mesh.proposed) != 1 || mesh.proposed[0]["node"] != nil || mesh.proposed[0]["replace"] != "true" || a.Next != meshWide {
		t.Fatalf("the mesh-wide layer is proposed first: %v %s", mesh.proposed, a.Next)
	}
	var values map[string]any
	_ = json.Unmarshal([]byte(mesh.proposed[0]["values"].(string)), &values)
	if values["accounts"] == nil || values[kindIdentities] == nil || values[kindTags] == nil || values["prefs"] == nil {
		t.Fatalf("the layer as it stands, with every derived kind and prefs: %v", values)
	}
	body, _ := json.Marshal(map[string]any{"prefs": values["prefs"]})
	if got, err := parseDeclaredPrefs(body); err != nil || !reflect.DeepEqual(got, shippedDefaultsWant) {
		t.Fatalf("the operator's 21 preferences, one entry each: %v %v", got, err)
	}
	if !strings.Contains(a.Proposed, "sab12") {
		t.Fatalf("%s", a.Proposed)
	}

	// While it waits nothing more is proposed.
	mesh.open = true
	if _, err := f.Derive(nil, false, true, nil, ""); err == nil || !strings.Contains(err.Error(), "sab12 (the whole mesh)") || len(mesh.proposed) != 1 {
		t.Fatalf("one open proposal of the module's at a time: %v", err)
	}
	// Approved: the mesh-wide layer holds it, so the next layer is shanks's own.
	mesh.open = false
	mesh.layers[""] = values
	a, err = f.Derive(nil, false, true, prefs, "")
	if err != nil {
		t.Fatal(err)
	}
	if len(mesh.proposed) != 2 || mesh.proposed[1]["node"] != "shanks" || a.Next != "shanks" ||
		!strings.Contains(mesh.proposed[1]["values"].(string), "standup") {
		t.Fatalf("then the node's own layer: %v", mesh.proposed)
	}
	var shanks map[string]any
	if err := json.Unmarshal([]byte(mesh.proposed[1]["values"].(string)), &shanks); err != nil {
		t.Fatal(err)
	}
	mesh.layers["shanks"] = shanks
	if a, err = f.Derive(nil, false, true, prefs, ""); err != nil || len(mesh.proposed) != 2 || !strings.HasPrefix(a.Next, "none") {
		t.Fatalf("nothing left to propose: %v %s", err, a.Next)
	}

	// A desktop node that does not answer: derived without it, never proposed.
	mesh.asleep = true
	a, err = f.Derive(nil, false, true, nil, meshWide)
	if err == nil || len(a.NotHeard) != 1 || !strings.Contains(err.Error(), "did not answer") || len(mesh.proposed) != 2 {
		t.Fatalf("a layer is never proposed without a desktop node: %v %v", err, a.NotHeard)
	}

	// A key to adopt is a node's: the mesh-wide layer's proposal refuses one.
	if err := proposable(map[string]any{kindCalendars: map[string]any{"c": map[string]any{"name": "C",
		"url": "https://dav.example.org/c/", "key": "c3"}}}, true); err == nil || !strings.Contains(err.Error(), "node's own layer") {
		t.Fatalf("%v", err)
	}
}

// Review 121: a layer the controller answers in any other words than its JSON or "no layer" refuses the proposal,
// because a proposal replaces the layer whole and would drop accounts.
func TestALayerThatCannotBeReadRefusesTheProposal(t *testing.T) {
	f := newFake(t)
	f.profileWithAccounts()
	f.profileWithConfiguration()
	f.declareAccounts(adoptable)
	links(t, nil)
	f2 := newFake(t)
	f2.profileWithAccounts()
	f2.declareAccounts(adoptable)
	mesh := &derivingMesh{t: t, shanks: f2, garbled: true}
	oldNode, oldAsk := nodeName, asker
	t.Cleanup(func() { nodeName, asker = oldNode, oldAsk })
	nodeName = func() string { return "g14" }
	asker = mesh.ask
	if _, err := f.Derive(nil, false, true, nil, ""); err == nil || !strings.Contains(err.Error(), "cannot be read as the layer") ||
		len(mesh.proposed) != 0 {
		t.Fatalf("the derive refuses: %v %v", err, mesh.proposed)
	}
	if _, err := f.ProfileAccounts(true); err == nil || !strings.Contains(err.Error(), "cannot be read as the layer") ||
		len(mesh.proposed) != 0 {
		t.Fatalf("betterbird_accounts refuses: %v %v", err, mesh.proposed)
	}
	if _, err := readLayer(""); err == nil {
		t.Fatal("an unreadable layer is an error, never an empty layer")
	}
	mesh.garbled = false
	if got, err := readLayer("shanks"); err != nil || len(got) != 0 {
		t.Fatalf("no layer, in the controller's words, is an empty layer: %v %v", got, err)
	}
}