package store

import (
	"path/filepath"
	"testing"
)

// seed inserts the local + remote rows a link's foreign keys require.
// (links.local / links.remote reference their own tables, so a link cannot
// exist on its own — the same reason ClaimFn upserts them before ReplaceLinks.)
func seed(t *testing.T, st *Store, locals []string, remote string) {
	t.Helper()
	for _, n := range locals {
		if err := st.UpsertLocal(Local{Name: n, IP: "127.0.0.1", Port: 8080, Protocol: "tcp"}); err != nil {
			t.Fatal(err)
		}
	}
	if err := st.UpsertRemote(Remote{Name: remote, IP: "1.2.3.4", Port: 7000, Token: "tok", Enabled: true}); err != nil {
		t.Fatal(err)
	}
}

// TestLinkByTripleSurvivesReplaceLinks pins the reason LinkByTriple exists.
//
// ReplaceLinks() rewrites the whole table with DELETE + re-INSERT, so sqlite
// hands every row a FRESH autoincrement id. A Link captured before such a
// write (e.g. one riding inside a ring token) therefore carries an id that
// either matches a different forward or matches nothing. The natural key
// (local, remote, remotePort) is what every caller actually identifies a
// forward by, and it must survive those rewrites.
func TestLinkByTripleSurvivesReplaceLinks(t *testing.T) {
	st, err := New(filepath.Join(t.TempDir(), "test.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer st.Close()

	seed(t, st, []string{"alpha", "beta", "gamma"}, "srv")
	links := []Link{
		{Local: "alpha", Remote: "srv", RemotePort: 100},
		{Local: "beta", Remote: "srv", RemotePort: 200},
		{Local: "gamma", Remote: "srv", RemotePort: 300},
	}
	if err := st.ReplaceLinks(links); err != nil {
		t.Fatal(err)
	}

	// Capture the ids as the ring would have them.
	before := map[string]int64{}
	all, err := st.ListLinks()
	if err != nil {
		t.Fatal(err)
	}
	for _, l := range all {
		before[l.Local] = l.ID
	}
	if len(before) != 3 {
		t.Fatalf("expected 3 links, got %d", len(before))
	}

	// Rewrite the table (this is what saveCanvas and ClaimFn both do).
	if err := st.ReplaceLinks(links); err != nil {
		t.Fatal(err)
	}
	after, err := st.ListLinks()
	if err != nil {
		t.Fatal(err)
	}
	if len(after) != 3 {
		t.Fatalf("expected 3 links after rewrite, got %d", len(after))
	}

	// The natural key must still resolve to the right forward, with its
	// disabled flag and group intact.
	for _, l := range after {
		if l.Disabled {
			t.Errorf("link %s unexpectedly disabled after a plain rewrite", l.Local)
		}
	}
	got, found, err := st.LinkByTriple("beta", "srv", 200)
	if err != nil {
		t.Fatal(err)
	}
	if !found {
		t.Fatal("LinkByTriple failed to find beta after ReplaceLinks")
	}
	if got.Local != "beta" || got.RemotePort != 200 {
		t.Fatalf("LinkByTriple returned the wrong row: %+v", got)
	}
}

// TestLinkByTripleNotFoundIsNotError documents the contract callers rely on:
// "no persisted opinion yet" is (Link{}, false, nil), not an error. A fresh
// claim of a link with no row must be allowed to start.
func TestLinkByTripleNotFoundIsNotError(t *testing.T) {
	st, err := New(filepath.Join(t.TempDir(), "test.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer st.Close()

	got, found, err := st.LinkByTriple("nope", "srv", 1234)
	if err != nil {
		t.Fatalf("missing link must not be an error, got %v", err)
	}
	if found {
		t.Fatalf("missing link reported as found: %+v", got)
	}
	if got.Local != "" || got.RemotePort != 0 {
		t.Fatalf("expected zero Link on miss, got %+v", got)
	}
}

// TestLinkByTripleReadsDisabledFlag is the store-level half of the
// "stopped forwards resurrect on restart" bug: the claim path asks the store
// whether the user disabled this forward, so this lookup must return the flag
// as persisted.
func TestLinkByTripleReadsDisabledFlag(t *testing.T) {
	st, err := New(filepath.Join(t.TempDir(), "test.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer st.Close()

	seed(t, st, []string{"mc"}, "srv")
	if err := st.ReplaceLinks([]Link{{Local: "mc", Remote: "srv", RemotePort: 25565, Group: "game"}}); err != nil {
		t.Fatal(err)
	}
	if err := st.SetLinkDisabled("mc", "srv", 25565, true); err != nil {
		t.Fatal(err)
	}

	ln, found, err := st.LinkByTriple("mc", "srv", 25565)
	if err != nil {
		t.Fatal(err)
	}
	if !found {
		t.Fatal("expected to find the link")
	}
	if !ln.Disabled {
		t.Fatal("expected Disabled=true to be visible through LinkByTriple")
	}
	if ln.Group != "game" {
		t.Fatalf("group should survive, got %q", ln.Group)
	}

	// ...and the user-facing start path must be able to clear it again.
	if err := st.SetLinkDisabled("mc", "srv", 25565, false); err != nil {
		t.Fatal(err)
	}
	if ln, _, _ := st.LinkByTriple("mc", "srv", 25565); ln.Disabled {
		t.Fatal("expected Disabled=false after clearing")
	}
}

// TestGetLinkByIDIsStaleAfterReplaceLinks documents WHY callers must not use
// GetLink(id) with a previously captured id. It is not a fix — it is the trap
// being pinned shut, so the hazard stays visible if someone reintroduces it.
func TestGetLinkByIDIsStaleAfterReplaceLinks(t *testing.T) {
	st, err := New(filepath.Join(t.TempDir(), "test.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer st.Close()

	seed(t, st, []string{"alpha", "beta", "gamma"}, "srv")
	if err := st.ReplaceLinks([]Link{
		{Local: "alpha", Remote: "srv", RemotePort: 100},
		{Local: "beta", Remote: "srv", RemotePort: 200},
	}); err != nil {
		t.Fatal(err)
	}
	all, _ := st.ListLinks()
	var staleID int64
	for _, l := range all {
		if l.Local == "alpha" {
			staleID = l.ID
		}
	}

	if err := st.ReplaceLinks([]Link{
		{Local: "alpha", Remote: "srv", RemotePort: 100},
		{Local: "beta", Remote: "srv", RemotePort: 200},
		{Local: "gamma", Remote: "srv", RemotePort: 300},
	}); err != nil {
		t.Fatal(err)
	}

	// The old id may still resolve, but to whatever row now occupies that
	// id — which is exactly the silent-mis-target hazard. Assert that the
	// natural key remains the only safe handle.
	if ln, ok := st.GetLink(staleID); ok && ln.Local != "alpha" {
		t.Logf("stale id %d now points at %q (hazard confirmed; use LinkByTriple)", staleID, ln.Local)
	}
	if got, found, _ := st.LinkByTriple("alpha", "srv", 100); !found || got.Local != "alpha" {
		t.Fatalf("natural key must stay reliable, got %+v found=%v", got, found)
	}
}