package main

import (
	"bytes"
	"os"
	"strings"
	"testing"

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

// An act says what it changed about the node it acted on, and nothing about the rest of the mesh
// (novox/hq ADR 0207): after the seat dependencies shipped, every `push <node>` and `assign` printed
// every node's unmet dependencies, a hundred lines around the one about the module just assigned.

func aContainer(name string) catalogue.Manifest {
	return catalogue.Manifest{Module: name, Version: "1",
		Resources: []map[string]any{{"id": name, "type": "container", "image": name}}}
}

func TestAnAssignmentSaysOnlyWhatItChangedOnItsOwnNode(t *testing.T) {
	open := aMesh(t)
	ctx := t.Context()
	register(t, open, aContainer("web"))
	register(t, open, aContainer("db"))
	// anchor already lacks a runtime for db: true, and not this act's to say.
	if _, err := open.inventory.Assign(ctx, "anchor", "db"); err != nil {
		t.Fatal(err)
	}
	if _, err := open.inventory.Assign(ctx, "laptop", "db"); err != nil {
		t.Fatal(err)
	}
	said, err := assign(ctx, open, "laptop", "web")
	if err != nil {
		t.Fatalf("%v\n%s", err, said)
	}
	if !strings.Contains(said, "web on laptop depends on "+catalogue.ContainerRuntimeSeat) {
		t.Errorf("the assignment does not say what the module it assigned depends on:\n%s", said)
	}
	for _, not := range []string{"db on laptop", "db on anchor", "anchor:"} {
		if strings.Contains(said, not) {
			t.Errorf("the assignment says %q, which it did not change:\n%s", not, said)
		}
	}
}

func TestAnAssignmentThatMeetsADependencySaysSo(t *testing.T) {
	shelf := map[string]catalogue.Manifest{
		"web": aContainer("web"),
		"docker": {Module: "docker", Claims: []catalogue.Claim{{Name: catalogue.ContainerRuntimeSeat}},
			Resources: []map[string]any{{"id": "d", "type": "container", "image": "dind"}}},
	}
	lines := unheldChange(shelf, "laptop", []string{"web"}, []string{"web", "docker"})
	if len(lines) != 1 || !strings.Contains(lines[0], "web on laptop now has "+catalogue.ContainerRuntimeSeat+" held") {
		t.Errorf("meeting a dependency said %v", lines)
	}
	// Taking the dependent off says nothing: the dependency went with its module.
	if lines := unheldChange(shelf, "laptop", []string{"web"}, nil); len(lines) != 0 {
		t.Errorf("unassigning the dependent said %v", lines)
	}
}

func TestAPushSaysANamedNodesDependenciesAndCountsTheRest(t *testing.T) {
	unheld := map[string][]catalogue.Unheld{
		"anchor": {{Node: "anchor", Module: "db", Seat: catalogue.ContainerRuntimeSeat}},
		"laptop": {{Node: "laptop", Module: "web", Seat: catalogue.ContainerRuntimeSeat},
			{Node: "laptop", Module: "sshd", Seat: catalogue.ServiceManagerSeat}},
	}
	var named bytes.Buffer
	reportUnheldPushed(&named, true, []string{"laptop"}, unheld)
	got := named.String()
	if !strings.Contains(got, "laptop has 2 unmet") || !strings.Contains(got, "web on laptop") ||
		!strings.Contains(got, "sshd on laptop") || strings.Contains(got, "anchor") {
		t.Errorf("a named push said:\n%s", got)
	}
	var all bytes.Buffer
	reportUnheldPushed(&all, false, []string{"anchor", "laptop", "quiet"}, unheld)
	want := "anchor: 1 unmet seat dependenc(ies) — see `status`\nlaptop: 2 unmet seat dependenc(ies) — see `status`\n"
	if all.String() != want {
		t.Errorf("a push to every node said:\n%s\nwant\n%s", all.String(), want)
	}
}

func TestOnlyTheServingControllerLogsEachChange(t *testing.T) {
	read := func(f func()) string {
		old := os.Stderr
		r, w, _ := os.Pipe()
		os.Stderr = w
		f()
		_ = w.Close()
		os.Stderr = old
		var b bytes.Buffer
		_, _ = b.ReadFrom(r)
		return b.String()
	}
	u := []catalogue.Unheld{{Node: "n1", Module: "web", Seat: catalogue.ContainerRuntimeSeat}}
	if got := read(func() { logUnheld("n1", u) }); got != "" {
		t.Errorf("a command logged:\n%s", got)
	}
	logUnheldChanges = true
	defer func() { logUnheldChanges = false }()
	if got := read(func() { logUnheld("n1", u) }); !strings.Contains(got, "web on n1") {
		t.Errorf("the serving controller did not log a change:\n%s", got)
	}
	if got := read(func() { logUnheld("n1", u) }); got != "" {
		t.Errorf("an unchanged report was logged again:\n%s", got)
	}
}