package web

import (
	"encoding/json"
	"os"
	"testing"

	"gitea.dooplex.hu/admin/felhom-controller/internal/agentapi"
)

// R-1192 follow-up (night 2026-10-21): the install page adds „A gépen nincs elég cserehely (swap)…" when memory is
// tight AND the agent reports the host's swap below the guest's RAM. An older agent (no number) is not judged.
// RED-PROOF: swapShort returning false always → the first case fails.
func TestR1192_SwapShortJudgesTheHostSwapAgainstTheGuestRAM(t *testing.T) {
	mb := func(v int64) *int64 { return &v }
	for _, c := range []struct {
		name string
		info agentapi.GuestMemoryInfo
		want bool
	}{
		{"a host with no swap", agentapi.GuestMemoryInfo{AllocatedMB: 4096, HostSwapMB: mb(0)}, true},
		{"a host with 2 GB swap behind a 4 GB guest", agentapi.GuestMemoryInfo{AllocatedMB: 4096, HostSwapMB: mb(2048)}, true},
		{"the installer's 8 GB host (7.75 GB swap)", agentapi.GuestMemoryInfo{AllocatedMB: 4096, HostSwapMB: mb(7935)}, false},
		{"an older agent (no number)", agentapi.GuestMemoryInfo{AllocatedMB: 4096}, false},
	} {
		if got := swapShort(c.info); got != c.want {
			t.Errorf("%s: swapShort = %v, want %v", c.name, got, c.want)
		}
	}
}

// R-1216 / D28 = A: the shared case table (byte-identical in felhom.eu hub/internal/api/testdata/, checked by felhom.eu
// scripts/host_swap_rule_gate.py), plus the page's own input: a 12 GB guest on an 8 GB-swap host (demo-felhom) is NOT
// short; the guest's RAM stands in when the agent sends no guest_swap_mb.
// RED-PROOF: with the morning's rule (`host < the guest's RAM`) the demo-hp, demo-felhom and 32 GB rows fail — seen
// failing 2026-10-22.
func TestR1216_HostSwapRuleCases(t *testing.T) {
	b, err := os.ReadFile("testdata/host_swap_rule_cases.json")
	if err != nil {
		t.Fatal(err)
	}
	var f struct {
		Cases []struct {
			Name  string `json:"name"`
			Host  int64  `json:"host_swap_mb"`
			Guest int64  `json:"guest_swap_mb"`
			Short bool   `json:"short"`
		} `json:"cases"`
	}
	if err := json.Unmarshal(b, &f); err != nil || len(f.Cases) < 10 {
		t.Fatalf("case table: %v (%d cases)", err, len(f.Cases))
	}
	mb := func(v int64) *int64 { return &v }
	for _, c := range f.Cases {
		if got := hostSwapRuleShort(c.Host, c.Guest); got != c.Short {
			t.Errorf("%s: host %d / guests %d → short=%t, want %t", c.Name, c.Host, c.Guest, got, c.Short)
		}
		// Through the page's own input, the agent's answer.
		if got := swapShort(agentapi.GuestMemoryInfo{AllocatedMB: c.Guest, HostSwapMB: mb(c.Host), GuestSwapMB: mb(c.Guest)}); got != c.Short {
			t.Errorf("%s (page input): short=%t, want %t", c.Name, got, c.Short)
		}
	}
	if swapShort(agentapi.GuestMemoryInfo{AllocatedMB: 12288, HostSwapMB: mb(8191)}) {
		t.Error("demo-felhom without guest_swap_mb (the guest's RAM stands in) must not be short")
	}
}