package console

import (
	"encoding/json"
	"testing"

	"github.com/carlosframework/platform/internal/boxid"
)

// The predicate and the choice are tested in internal/boxchoice. These
// tests hold console's conversion to it: every field the predicate reads
// must survive boxSnapshot, or a box would silently read as missing it.

// haBox is an eligible box's edges file in placement "uk".
func haBox(id string, mut func(m map[string]any)) string {
	m := map[string]any{
		"v": 1, "box": id, "box_id": id, "eip": "1.2.3.4", "region": "eu-west-2", "placement": "uk",
		"hosts": map[string]any{}, "hibernation_configured": true, "serves_shared_pool": true,
		"accepts_inbound": true, "secrets_key_fp": testKeyFP, "capabilities": []string{"region-ha-1"},
		"headroom": map[string]any{"mem_free_mib": 1000, "disk_free_mib": 2000, "awake": 3},
	}
	if mut != nil {
		mut(m)
	}
	b, _ := json.Marshal(m)
	return string(b)
}

func ids(cs []boxCandidate) []string {
	out := make([]string, len(cs))
	for i, c := range cs {
		out[i] = c.BoxID
	}
	return out
}

// rosterFor enrolls each box in placement "uk" as an instance in eu-west-2.
func rosterFor(boxes ...string) map[string]rosterBox {
	out := map[string]rosterBox{}
	for _, b := range boxes {
		out[b] = rosterBox{Placement: "uk", Cloud: boxid.Cloud{Provider: "aws", Account: "1", Region: "eu-west-2", InstanceID: "i-" + b}}
	}
	return out
}

func TestEligibleBoxesCarriesEveryFieldThePredicateReads(t *testing.T) {
	del := func(k string) func(map[string]any) { return func(m map[string]any) { delete(m, k) } }
	set := func(k string, v any) func(map[string]any) { return func(m map[string]any) { m[k] = v } }
	cases := []struct {
		name string
		mut  func(map[string]any)
		want bool
	}{
		{"all present", nil, true},
		{"no dial address", set("eip", ""), false},
		{"hibernation unconfigured", set("hibernation_configured", false), false},
		{"hibernation unknown", del("hibernation_configured"), false},
		{"refuses the shared pool", set("serves_shared_pool", false), false},
		{"refuses inbound", set("accepts_inbound", false), false},
		{"wrong secrets key", set("secrets_key_fp", "sha256:other"), false},
		{"no capability", del("capabilities"), false},
		{"draining", set("draining", true), false},
		{"another placement", set("placement", "us"), false},
		{"another region", set("region", "us-east-1"), false},
		{"box_id names no roster entry", set("box_id", "i-0zzz"), false},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			snap := views(t, haBox("i-0aaa", tc.mut))
			got := eligibleBoxes(snap, rosterFor("i-0aaa"), "uk", "eu-west-2", "ie", testKeyFP, nil)
			if (len(got) == 1) != tc.want {
				t.Fatalf("eligible = %v, want %v", ids(got), tc.want)
			}
		})
	}
	got := eligibleBoxes(views(t, haBox("i-0aaa", nil)), rosterFor("i-0aaa"), "uk", "eu-west-2", "ie", testKeyFP, nil)
	if want := (boxCandidate{BoxID: "i-0aaa", Region: "eu-west-2", MemFreeMiB: 1000, DiskFreeMiB: 2000, Awake: 3}); len(got) != 1 || got[0] != want {
		t.Fatalf("got %+v, want %+v", got, want)
	}
	if got := eligibleBoxes(markStale(views(t, haBox("i-0aaa", nil)), "i-0aaa"), rosterFor("i-0aaa"), "uk", "eu-west-2", "ie", testKeyFP, nil); len(got) != 0 {
		t.Fatalf("a stale box is eligible: %v", ids(got))
	}
}

// Both halves of console's completeness carry over: an unread edges file,
// and unknown liveness.
func TestEligibleBoxesAnIncompleteSnapshotOffersNothing(t *testing.T) {
	for _, bend := range []func(*edgesSnapshot){
		func(s *edgesSnapshot) { s.Complete = false },
		func(s *edgesSnapshot) { s.BoxesComplete = false },
	} {
		snap := views(t, haBox("i-0aaa", nil))
		bend(&snap)
		if got := eligibleBoxes(snap, rosterFor("i-0aaa"), "uk", "eu-west-2", "ie", testKeyFP, nil); len(got) != 0 {
			t.Fatalf("got %v from an incomplete snapshot", ids(got))
		}
	}
}

func TestChooseBoxIsBoxchoiceChoose(t *testing.T) {
	a, b := boxCandidate{BoxID: "i-0aaa"}, boxCandidate{BoxID: "i-0bbb"}
	got, ok := chooseBox("shop.bab.oncarlos.com", []boxCandidate{a, b}, map[string]boxLoad{"i-0aaa": {Hosts: 5}, "i-0bbb": {Hosts: 2}}, "bab/jam")
	if !ok || got.BoxID != "i-0bbb" {
		t.Fatalf("got %s ok=%v, want i-0bbb", got.BoxID, ok)
	}
}