package main

import (
	"reflect"
	"strings"
	"testing"

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

// novox/hq ADR 0419: a group's order, from the module graph and the manifests' change alone, the same on every
// reading — what a module stands on before it, the controller before a manifest that needs it, the node-engine
// before the controller, a verb's server before its caller — and no `after:` line read.
func TestAGroupIsOrderedByTheGraphAndTheManifestsChange(t *testing.T) {
	members := []orderMember{
		{ID: "cat", Repository: "novox/mesh-catalog"},
		{ID: "ctl", Repository: "novox/mesh-controller"},
		{ID: "host", Repository: "novox/mesh-host"},
		{ID: "base", Repository: "novox/base"},
		{ID: "app", Repository: "novox/app"},
		{ID: "lab", Repository: "novox/lab"},
	}
	reach := map[string]orderReach{
		"cat":  {Moved: []string{"gitea"}, Manifests: []string{"modules/gitea/module.json"}},
		"ctl":  {Moved: []string{"mesh-controller"}, Manifests: []string{"module.json"}},
		"host": {Moved: []string{"mesh-host"}, Manifests: []string{"module.json"}},
		"base": {Moved: []string{"base"}},
		"app":  {Moved: []string{"app"}},
		"lab":  {Moved: []string{"lab"}},
	}
	edges := []inventory.Edge{{From: "app", To: "base", Kind: inventory.EdgeStandsOn},
		{From: "gitea", To: "postgres", Kind: inventory.EdgeDeclared}}
	changes := map[string]moduleChange{"gitea": {Manifest: true}, "mesh-controller": {Manifest: true},
		"mesh-host": {Manifest: true}, "lab": {Serves: []string{"seat.v"}}, "app": {Invokes: []string{"seat.v"}}}
	got := orderOf(members, reach, edges, changes)
	if len(got.Cycle) > 0 {
		t.Fatalf("a cycle where there is none: %v", got.Cycle)
	}
	// By repository among those with nothing before them: app waits for base and lab; gitea's catalogue for the controller.
	want := []string{"base", "lab", "app", "host", "ctl", "cat"}
	if !reflect.DeepEqual(got.Order, want) {
		t.Fatalf("ordered %v, wanted %v; pairs %+v", got.Order, want, got.Pairs)
	}
	why := map[string]string{}
	for _, p := range got.Pairs {
		why[p.Before+">"+p.After] = p.Why
	}
	for pair, reason := range map[string]string{"host>ctl": ruleEngineFirst, "ctl>cat": ruleVersionSkew,
		"ctl>host": "", "base>app": orderBuiltBy, "lab>app": ruleVerbBeforeCaller + ": seat.v"} {
		if why[pair] != reason {
			t.Errorf("%s is ordered %q, wanted %q", pair, why[pair], reason)
		}
	}
	// The same members in another order read the same.
	shuffled := []orderMember{members[5], members[3], members[0], members[4], members[2], members[1]}
	if again := orderOf(shuffled, reach, edges, changes); !reflect.DeepEqual(again.Order, want) {
		t.Fatalf("another reading ordered %v", again.Order)
	}
}

// A cycle is the one refusal, and it names every module and edge. A description's `after:` line changes nothing.
func TestAGroupInACycleIsNamedAndNothingElseIsRefused(t *testing.T) {
	members := []orderMember{
		{ID: "x", Repository: "novox/x", Number: 7},
		{ID: "y", Repository: "novox/y", Number: 9},
	}
	reach := map[string]orderReach{"x": {Moved: []string{"mx"}}, "y": {Moved: []string{"my"}}}
	changes := map[string]moduleChange{
		"mx": {Serves: []string{"s.a"}, Invokes: []string{"s.b"}},
		"my": {Serves: []string{"s.b"}, Invokes: []string{"s.a"}},
	}
	got := orderOf(members, reach, nil, changes)
	if !reflect.DeepEqual(got.Cycle, []string{"x", "y"}) || len(got.Order) > 0 {
		t.Fatalf("a cycle was ordered: %v, cycle %v", got.Order, got.Cycle)
	}
	for _, w := range []string{"mx", "my", "s.a", "s.b"} {
		if !strings.Contains(got.CycleSaid, w) {
			t.Errorf("the cycle does not say %q: %s", w, got.CycleSaid)
		}
	}
	// Without the edges the same members are ordered by repository.
	got = orderOf(members, reach, nil, nil)
	if !reflect.DeepEqual(got.Order, []string{"x", "y"}) || len(got.Cycle) > 0 || len(got.Pairs) > 0 {
		t.Fatalf("members with no edge: %v %v %+v", got.Order, got.Cycle, got.Pairs)
	}
}

// novox/hq ADR 0239 decision 8: a walk waits for the delivery's owner only while the seat has a holder on
// record, and never one that moves a module on the controller's own path.
func TestAWalkWaitsOnlyWhileTheDeliverySeatIsHeldAndNeverForTheCore(t *testing.T) {
	holder := inventory.Entry{Manifest: catalogue.Manifest{Module: "mesh-delivery",
		Claims: []catalogue.Claim{{Name: catalogue.DeliverySeat, Scope: catalogue.ScopeMesh}}}, On: []string{"anchor"}}
	unassigned := holder
	unassigned.On = nil
	for _, c := range []struct {
		entries []inventory.Entry
		moved   []string
		waits   bool
	}{
		{nil, []string{"gitea"}, false},
		{[]inventory.Entry{unassigned}, []string{"gitea"}, false},
		{[]inventory.Entry{holder}, []string{"gitea", "plex"}, true},
		{[]inventory.Entry{holder}, []string{"gitea", "mesh-controller"}, false},
		{[]inventory.Entry{holder}, []string{"mesh-host"}, false},
		{[]inventory.Entry{holder}, []string{"node-tools"}, false},
		{[]inventory.Entry{holder}, []string{"nats"}, false},
		{[]inventory.Entry{holder}, []string{"mesh-delivery", "gitea"}, false},
	} {
		d := awaitsFor(c.entries, c.moved)
		if (d != nil) != c.waits {
			t.Errorf("held %v, moving %v: waits %v, wanted %v", len(c.entries) > 0 && len(c.entries[0].On) > 0,
				c.moved, d != nil, c.waits)
		}
		if d != nil && d.Awaits != catalogue.DeliverySeat {
			t.Errorf("waits for %q", d.Awaits)
		}
	}
}

// novox/hq ADR 0239: with mesh-delivery on record, a merge opens its walk and asks nothing until the
// delivery's word; the word starts it; the core's own merge never waits; a person starts a waiting walk by
// hand when the owner is down, and the owner's stop ends one as stopped.

// The verbs mesh-delivery asks with become the commands they name, and nothing a caller sends is passed over.
func TestTheDeliveryVerbsComposeTheirCommands(t *testing.T) {
	for _, c := range []struct {
		verb string
		args map[string]any
		want []string
	}{
		{"deliver", map[string]any{"plan": "plan-1", "why": "its turn"},
			[]string{"delivery", "go", "plan-1", "--by", "mesh-delivery", "--why", "its turn"}},
		{"delivery-stop", map[string]any{"plan": "plan-1", "why": "w", "by": "jochen"},
			[]string{"delivery", "stop", "plan-1", "--why", "w", "--by", "mesh-delivery for jochen"}},
		{"delivery-walks", map[string]any{}, []string{"delivery", "walks"}},
		{"delivery-walks", map[string]any{"plan": "plan-1"}, []string{"delivery", "walks", "--plan", "plan-1"}},
		{"delivery-order", map[string]any{"members": "[]"}, []string{"delivery", "order", "--members", "[]"}},
		{"delivery-check", map[string]any{"group": "feat/x", "members": "[]"},
			[]string{"delivery", "check", "--group", "feat/x", "--members", "[]"}},
		{"delivery-plan", map[string]any{"repository": "novox/a", "paths": "x", "head": "c0"},
			[]string{"delivery", "plan", "--repository", "novox/a", "--paths", "x", "--head", "c0"}},
		{"plans", map[string]any{"go": "plan-1", "why": "down"}, []string{"plans", "go", "plan-1", "--why", "down"}},
	} {
		got, err := argvFor(c.verb, c.args)
		if err != nil || !reflect.DeepEqual(got, c.want) {
			t.Errorf("%s %v → %v %v, wanted %v", c.verb, c.args, got, err, c.want)
		}
	}
	if _, err := argvFor("deliver", map[string]any{}); err == nil {
		t.Error("deliver without a walk was composed")
	}
	if _, err := argvFor("delivery-stop", map[string]any{"plan": "p"}); err == nil {
		t.Error("a stop without why was composed")
	}
}

// A verb runs as a command of its own: what it keeps of a walk is still said as plan-moved, on a bus of the
// command's own, so the delivery's owner hears it at once and not only when it reads the walks back.