package app

import (
	"strings"
	"testing"
)

// A bracketed paste inserts at the cursor in the main composer (insert mode, no overlay).
func TestHandlePasteIntoComposer(t *testing.T) {
	m := NewModel(nil)
	m.editMode, m.overlay = ModeInsert, OverlayNone
	m.inputBuffer, m.inputCursor = "ab", 1
	m = m.handlePaste("XY").(Model)
	if m.inputBuffer != "aXYb" || m.inputCursor != 3 {
		t.Fatalf("composer paste = (%q,%d), want (%q,3)", m.inputBuffer, m.inputCursor, "aXYb")
	}
}

// A paste while steering appends to the steer note, not the input buffer.
func TestHandlePasteWhileSteering(t *testing.T) {
	m := NewModel(nil)
	m.steering = true
	m.steerBuffer = "go "
	m = m.handlePaste("now").(Model)
	if m.steerBuffer != "go now" || m.inputBuffer != "" {
		t.Fatalf("steer paste = steer:%q input:%q", m.steerBuffer, m.inputBuffer)
	}
}

// Alt+Backspace deletes the word (plus trailing spaces) left of the cursor.
func TestDeleteWordBack(t *testing.T) {
	cases := []struct {
		buf     string
		cur     int
		wantBuf string
		wantCur int
	}{
		{"foo bar", 7, "foo ", 4},
		{"foo bar  ", 9, "foo ", 4},
		{"foo bar baz", 7, "foo  baz", 4}, // cursor mid-string
		{"one", 3, "", 0},
		{"", 0, "", 0},
	}
	for _, c := range cases {
		m := NewModel(nil)
		m.inputBuffer, m.inputCursor = c.buf, c.cur
		m.deleteWordBack()
		if m.inputBuffer != c.wantBuf || m.inputCursor != c.wantCur {
			t.Errorf("deleteWordBack(%q,%d) = (%q,%d), want (%q,%d)",
				c.buf, c.cur, m.inputBuffer, m.inputCursor, c.wantBuf, c.wantCur)
		}
	}
}

// F-006: a multi-line paste must collapse to a single display line so the fixed-height
// input box can't overflow and leave a smeared/stale region.
func TestFlattenForDisplay(t *testing.T) {
	cases := map[string]string{
		"plain text":         "plain text",
		"line one\nline two": "line one↵ line two",
		"crlf\r\nhere":       "crlf↵ here",
		"tab\tseparated":     "tab separated",
		"a\nb\nc":            "a↵ b↵ c",
	}
	for in, want := range cases {
		if got := flattenForDisplay(in); got != want {
			t.Errorf("flattenForDisplay(%q) = %q, want %q", in, got, want)
		}
		if strings.ContainsAny(flattenForDisplay(in), "\n\r\t") {
			t.Errorf("flattenForDisplay(%q) still contains a control char", in)
		}
	}
}