package kbblock

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	sdkfade "git.hangman-lab.top/hzhang/Plexum-sdk-go/fade"
)

func TestSessionDir(t *testing.T) {
	got := SessionDir("/root/.plexum", "alice", "s_1")
	want := "/root/.plexum/agents/alice/sessions/s_1/plugins/harbor-forge"
	if got != want {
		t.Errorf("SessionDir = %q want %q", got, want)
	}
}

func TestOpenMissingFile(t *testing.T) {
	b, err := Open(t.TempDir(), "alice", "s_1")
	if err != nil {
		t.Fatal(err)
	}
	if b.Len() != 0 || b.NextSeq != 1 {
		t.Errorf("empty open: Len=%d NextSeq=%d", b.Len(), b.NextSeq)
	}
}

func TestOpenRequiresAllArgs(t *testing.T) {
	if _, err := Open("", "a", "s"); err == nil {
		t.Error("want error on empty profileRoot")
	}
	if _, err := Open("/x", "", "s"); err == nil {
		t.Error("want error on empty agentID")
	}
	if _, err := Open("/x", "a", ""); err == nil {
		t.Error("want error on empty sessionID")
	}
}

func TestAddAndDuplicate(t *testing.T) {
	b, _ := Open(t.TempDir(), "a", "s")
	e := b.Add(42, "KB-PAYROT", "debugging", "OOM fix", 3)
	if e == nil || e.ID != 42 || e.KBCode != "KB-PAYROT" || e.SourceTopic != "debugging" ||
		e.InsertSeq != 1 || e.AddedAtTurn != 3 {
		t.Errorf("entry wrong: %+v", e)
	}
	if b.Add(42, "X", "y", "z", 7) != nil {
		t.Error("dup should return nil")
	}
	if b.Len() != 1 {
		t.Errorf("Len=%d", b.Len())
	}
}

func TestRoundtrip(t *testing.T) {
	dir := t.TempDir()
	b, _ := Open(dir, "a", "s")
	b.Add(101, "KB-A", "topic-a", "a", 1)
	b.Add(202, "KB-A", "topic-b", "b", 2)
	if err := b.Save(); err != nil {
		t.Fatal(err)
	}
	b2, _ := Open(dir, "a", "s")
	if b2.Len() != 2 || b2.NextSeq != 3 {
		t.Errorf("reopen Len=%d NextSeq=%d", b2.Len(), b2.NextSeq)
	}
	if !b2.Has(101) || !b2.Has(202) {
		t.Error("entries missing after reopen")
	}
}

func TestRenderInsertOrder(t *testing.T) {
	b, _ := Open(t.TempDir(), "a", "s")
	b.Add(999, "K", "t", "first", 0)
	b.Add(1, "K", "t", "second", 0)
	out := b.Render()
	idx999 := strings.Index(out, "id=999")
	idx1 := strings.Index(out, "id=1 ")
	if !(idx999 >= 0 && idx1 > idx999) {
		t.Errorf("order broken: %q", out)
	}
}

func TestRenderAttributes(t *testing.T) {
	b, _ := Open(t.TempDir(), "a", "s")
	b.Add(42, "KB-PAYROT", "debugging", "OOM fix: bump heap", 0)
	out := b.Render()
	if !strings.HasPrefix(out, "<kb-fact id=42 kb=KB-PAYROT source=topic:debugging>\n") {
		t.Errorf("head wrong: %q", out)
	}
	if !strings.HasSuffix(out, "</kb-fact>\n") {
		t.Errorf("tail wrong: %q", out)
	}
}

func TestRenderOmitsSourceWhenEmpty(t *testing.T) {
	b, _ := Open(t.TempDir(), "a", "s")
	b.Add(7, "KB-X", "", "raw", 0)
	out := b.Render()
	if strings.Contains(out, "source=topic:") {
		t.Errorf("source attr leaked: %q", out)
	}
	if !strings.Contains(out, "<kb-fact id=7 kb=KB-X>") {
		t.Errorf("tight tag missing: %q", out)
	}
}

func TestRemove(t *testing.T) {
	b, _ := Open(t.TempDir(), "a", "s")
	b.Add(1, "K", "t", "a", 0)
	b.Add(2, "K", "t", "b", 0)
	b.Add(3, "K", "t", "c", 0)
	removed := b.Remove(2, 99, 3)
	if len(removed) != 2 {
		t.Errorf("removed=%v", removed)
	}
	if b.Len() != 1 || !b.Has(1) {
		t.Errorf("post-state wrong: Len=%d", b.Len())
	}
}

func TestRenderEmpty(t *testing.T) {
	b, _ := Open(t.TempDir(), "a", "s")
	if b.Render() != "" {
		t.Error("empty Render should be \"\"")
	}
}

func TestAddPopulatesSeed(t *testing.T) {
	b, _ := Open(t.TempDir(), "a", "s")
	e := b.Add(1, "K", "t", "x", 0)
	if e == nil || e.Seed == 0 {
		t.Errorf("Seed should be non-zero, got %d", e.Seed)
	}
}

func TestRenderFadedDistanceZeroIsIdentity(t *testing.T) {
	b, _ := Open(t.TempDir(), "a", "s")
	b.Add(1, "K", "t", "hello world", 5)
	plain := b.Render()
	faded := b.RenderFaded(5, sdkfade.DefaultFadeParams())
	if plain != faded {
		t.Errorf("d=0 should be no-op:\nplain=%q\nfaded=%q", plain, faded)
	}
}

func TestRenderFadedAppliesMaskOverTime(t *testing.T) {
	b, _ := Open(t.TempDir(), "a", "s")
	b.Add(1, "K", "t", "the quick brown fox jumps over the lazy dog", 0)
	plain := b.Render()
	faded := b.RenderFaded(20, sdkfade.DefaultFadeParams())
	if plain == faded {
		t.Errorf("d=20 should mask, but identical: %q", plain)
	}
	if !strings.Contains(faded, "_") {
		t.Errorf("expected underscore masking in faded output: %q", faded)
	}
}

func TestTickDropsHighlyFaded(t *testing.T) {
	b, _ := Open(t.TempDir(), "a", "s")
	b.Add(1, "K", "t", "short", 0)
	b.Add(2, "K", "t", "this entry stays freshish", 100)
	res := b.Tick(105, sdkfade.DefaultFadeParams())
	hasID1Dropped := false
	for _, id := range res.FadedOut {
		if id == 1 {
			hasID1Dropped = true
		}
	}
	if !hasID1Dropped {
		t.Errorf("entry 1 (d=105) should have crossed drop threshold: faded=%v", res.FadedOut)
	}
	if !b.Has(2) {
		t.Error("entry 2 (d=5) should still be present")
	}
}

func TestRefreshResetsClock(t *testing.T) {
	b, _ := Open(t.TempDir(), "a", "s")
	b.Add(1, "K", "t", "content", 0)
	oldSeed := b.Lookup(1).Seed
	got := b.Refresh([]int{1, 99}, 50)
	if len(got) != 1 || got[0] != 1 {
		t.Errorf("Refresh returned %v, want [1]", got)
	}
	e := b.Lookup(1)
	if e.LastRefreshAtTurn != 50 {
		t.Errorf("LastRefreshAtTurn = %d, want 50", e.LastRefreshAtTurn)
	}
	if e.Seed == oldSeed {
		t.Error("Refresh should regenerate Seed")
	}
}

func TestSaveEmptyNoFile(t *testing.T) {
	dir := t.TempDir()
	b, _ := Open(dir, "a", "s")
	if err := b.Save(); err != nil {
		t.Fatal(err)
	}
	path := filepath.Join(SessionDir(dir, "a", "s"), FileName)
	if _, err := os.Stat(path); !os.IsNotExist(err) {
		t.Errorf("file should not exist: %v", err)
	}
}