package app

import (
	"io"
	"os"
	"testing"

	"github.com/hjbdev/patterm/internal/scratchpad"
)

func silenceStdout(t *testing.T) {
	t.Helper()
	old := os.Stdout
	r, w, err := os.Pipe()
	if err != nil {
		t.Fatalf("pipe stdout: %v", err)
	}
	done := make(chan struct{})
	go func() {
		_, _ = io.Copy(io.Discard, r)
		close(done)
	}()
	os.Stdout = w
	t.Cleanup(func() {
		os.Stdout = old
		_ = w.Close()
		<-done
		_ = r.Close()
	})
}

func newScratchpadDeleteTestState(t *testing.T) (*uiState, *scratchpad.Store) {
	t.Helper()
	t.Setenv("XDG_DATA_HOME", t.TempDir())
	pads, err := scratchpad.Open("scratchpad-delete-test")
	if err != nil {
		t.Fatalf("scratchpad.Open: %v", err)
	}
	sess := NewSession(t.TempDir(), "scratchpad-delete-test")
	t.Cleanup(sess.Shutdown)
	st := &uiState{
		sess:       sess,
		pads:       pads,
		hostCols:   120,
		hostRows:   40,
		chromeWake: make(chan struct{}, 1),
	}
	return st, pads
}

func TestDeletingFocusedScratchpadFocusesAnotherPad(t *testing.T) {
	silenceStdout(t)
	st, pads := newScratchpadDeleteTestState(t)
	if _, err := pads.Write("alpha.md", "alpha", ""); err != nil {
		t.Fatalf("write alpha: %v", err)
	}
	if _, err := pads.Write("beta.md", "beta", ""); err != nil {
		t.Fatalf("write beta: %v", err)
	}
	st.focusedPad = "alpha.md"
	st.focusedName = "alpha.md"
	st.padOffsetName = "alpha.md"
	st.padOffset = 3

	st.handlePadDelete("alpha.md")

	if st.focusedPad != "beta.md" {
		t.Fatalf("focusedPad = %q, want beta.md", st.focusedPad)
	}
	if st.focusedID != "" {
		t.Fatalf("focusedID = %q, want empty while another pad is focused", st.focusedID)
	}
	if st.padOffset != 0 || st.padOffsetName != "beta.md" {
		t.Fatalf("pad offset = (%q,%d), want (beta.md,0)", st.padOffsetName, st.padOffset)
	}
}

func TestDeletingLastFocusedScratchpadFocusesRunningChild(t *testing.T) {
	silenceStdout(t)
	st, pads := newScratchpadDeleteTestState(t)
	if _, err := pads.Write("only.md", "only", ""); err != nil {
		t.Fatalf("write only: %v", err)
	}
	child := makeFakeChild("pid", "devserver", KindCommand)
	addChild(st.sess, child)
	st.focusedPad = "only.md"
	st.focusedName = "only.md"

	st.handlePadDelete("only.md")

	if st.focusedPad != "" {
		t.Fatalf("focusedPad = %q, want empty after falling back to child", st.focusedPad)
	}
	if st.focusedID != "pid" {
		t.Fatalf("focusedID = %q, want pid", st.focusedID)
	}
}