package main

import (
	"crypto/ecdh"
	"crypto/rand"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"testing"

	"github.com/novox/mesh-control/internal/catalogue"
	"github.com/novox/mesh-control/internal/inventory"
	"github.com/novox/mesh-control/internal/licences"
	"github.com/novox/mesh-control/internal/overlay"
)

// A mesh a command can be run against.
//
// The commands here were tested through the pieces they call and never through themselves, so
// three faults that only exist where the pieces meet — an assignment reported as fine while it
// blocked other machines, a read-shaped invocation that wrote, a JSON interface that stopped
// emitting JSON — were invisible to every test in this package. This raises the real stores and
// calls the real functions.

// aMesh is two placed, capable machines on a private network, with nothing assigned but the
// network itself.
//
// `anchor` is the hub. That is not decoration: a mesh whose hub cannot be resolved has no private
// network at all, which is how one machine's problem reaches every other.
func aMesh(t *testing.T) *stores {
	t.Helper()
	inventory.ForTest(t) // raises the store, migrates it, and points the environment at it
	licences.ForTest(t)  // planning reaches this one too, by name and never by connection

	open, err := openStores(t.Context())
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(open.Close)
	for _, m := range provided {
		if err := open.inventory.Provide(t.Context(), m); err != nil {
			t.Fatal(err)
		}
	}

	for i, name := range []string{"anchor", "laptop"} {
		record, err := open.inventory.AddNode(t.Context(), name)
		if err != nil {
			t.Fatal(err)
		}
		if err := open.inventory.SetPlace(t.Context(), name, name+".example:51820", "here",
			name == "anchor", fmt.Sprintf("10.77.0.%d", i+1)); err != nil {
			t.Fatal(err)
		}
		reported, err := json.Marshal(map[string]any{"capabilities": []map[string]any{
			{"name": "container-runtime", "present": true},
			{"name": "wireguard", "present": true},
			{"name": "systemd", "present": true},
		}})
		if err != nil {
			t.Fatal(err)
		}
		var profile map[string]any
		if err := json.Unmarshal(reported, &profile); err != nil {
			t.Fatal(err)
		}
		if err := open.inventory.RecordProfile(t.Context(), record.ID, profile); err != nil {
			t.Fatal(err)
		}
		if err := open.inventory.RecordSealingKey(t.Context(), record.ID, aPublicKey(t)); err != nil {
			t.Fatal(err)
		}
		if err := open.inventory.RecordOverlayKey(t.Context(), record.ID, aPublicKey(t)); err != nil {
			t.Fatal(err)
		}
		if err := open.inventory.Assign(t.Context(), name, overlay.Name); err != nil {
			t.Fatal(err)
		}
	}
	return open
}

// aPublicKey is a key a machine could have reported. Its private half is thrown away: nothing here
// opens anything, it only needs the mesh to believe a machine has a key.
func aPublicKey(t *testing.T) string {
	t.Helper()
	k, err := ecdh.X25519().GenerateKey(rand.Reader)
	if err != nil {
		t.Fatal(err)
	}
	return base64.StdEncoding.EncodeToString(k.PublicKey().Bytes())
}

// register puts a manifest in the catalogue.
func register(t *testing.T, open *stores, m catalogue.Manifest) {
	t.Helper()
	if err := open.inventory.RegisterModule(t.Context(), m, inventory.Source{}); err != nil {
		t.Fatal(err)
	}
}

// rivals are two modules that cannot share a machine, which is the shortest way to make a node's
// own set of assignments incoherent using nothing but commands a person has.
func rivals() (catalogue.Manifest, catalogue.Manifest) {
	claim := []catalogue.Claim{{Name: "the-seat", Scope: catalogue.ScopeNode}}
	return catalogue.Manifest{Module: "rival-one", Version: "1", Claims: claim},
		catalogue.Manifest{Module: "rival-two", Version: "1", Claims: claim}
}