package host

import (
	"errors"
	"strings"
	"testing"

	"github.com/carlosframework/platform/internal/caps"
	"github.com/carlosframework/platform/internal/cgroup"
	"github.com/carlosframework/platform/internal/registry"
	"github.com/carlosframework/platform/internal/release"
)

// TestMemTier: the tier is a platform choice keyed on ONE manifest bit.
// Everything that isn't "declares children" — no manifest, no
// capabilities block, an unreadable sibling — is the default tier: the
// safe direction is the smaller cap, and the caps pass will say why the
// sibling is unreadable in its own advice.
func TestMemTier(t *testing.T) {
	rt := registry.Route{Host: "h.example.com", App: "app"}
	cases := []struct {
		name string
		m    *release.Manifest
		err  error
		want cgroup.Limit
	}{
		{"no manifest", nil, nil, cgroup.TierDefault},
		{"unreadable", nil, errors.New("boom"), cgroup.TierDefault},
		{"no capabilities", &release.Manifest{}, nil, cgroup.TierDefault},
		{"capabilities, no children", &release.Manifest{Capabilities: &caps.Set{V: caps.Version}}, nil, cgroup.TierDefault},
		{"children", &release.Manifest{Capabilities: &caps.Set{V: caps.Version, Children: true}}, nil, cgroup.TierChildren},
	}
	for _, c := range cases {
		tier := memTier(func(registry.Route) (*release.Manifest, error) { return c.m, c.err })
		if got := tier(rt); got != c.want {
			t.Errorf("%s: tier = %v, want %v", c.name, got, c.want)
		}
	}
}

// memTierOf reads the NAMED version's manifest, never the live link's: a
// generation's limits are its own artifact's (zero-downtime spec §7.3).
func TestMemTierOfReadsTheNamedVersion(t *testing.T) {
	rt := registry.Route{Host: "h.example.com", App: "app"}
	var asked []string
	tier := memTierOf(func(_ registry.Route, v string) (*release.Manifest, error) {
		asked = append(asked, v)
		if v == "v1" {
			return &release.Manifest{Capabilities: &caps.Set{V: caps.Version, Children: true}}, nil
		}
		return &release.Manifest{}, nil
	})
	if got := tier(rt, "v1"); got != cgroup.TierChildren {
		t.Errorf("v1 = %v, want the children tier", got)
	}
	if got := tier(rt, "v2"); got != cgroup.TierDefault {
		t.Errorf("v2 = %v, want the default tier", got)
	}
	if strings.Join(asked, ",") != "v1,v2" {
		t.Errorf("read the manifests of %v, want v1 then v2", asked)
	}
}