package app

import (
	"testing"
	"time"
)

func TestMarqueeStepFits(t *testing.T) {
	var m marqueeState
	now := time.Unix(0, 0)
	off, animating, _ := m.step("a", 5, 10, now)
	if animating {
		t.Fatalf("expected no animation when name fits in budget")
	}
	if off != 0 {
		t.Fatalf("expected offset 0, got %d", off)
	}
}

func TestMarqueePhaseProgression(t *testing.T) {
	var m marqueeState
	// name 10 runes, budget 5 → maxOffset = 5.
	const nameLen, budget = 10, 5
	t0 := time.Unix(0, 0)

	// At t0: phaseHoldStart, offset 0, animating.
	off, anim, wake := m.step("row", nameLen, budget, t0)
	if off != 0 || !anim || wake != marqueeHoldStart {
		t.Fatalf("t0: off=%d anim=%v wake=%v", off, anim, wake)
	}

	// Just before hold expires: still offset 0.
	off, anim, _ = m.step("row", nameLen, budget, t0.Add(marqueeHoldStart-time.Millisecond))
	if off != 0 || !anim {
		t.Fatalf("pre-expiry hold: off=%d anim=%v", off, anim)
	}

	// At hold expiry + 1 step: should have transitioned to scroll, offset 1.
	off, anim, _ = m.step("row", nameLen, budget, t0.Add(marqueeHoldStart+marqueeStep))
	if !anim || off != 1 {
		t.Fatalf("first scroll step: off=%d anim=%v", off, anim)
	}

	// Mid-scroll: offset == 3.
	off, _, _ = m.step("row", nameLen, budget, t0.Add(marqueeHoldStart+3*marqueeStep))
	if off != 3 {
		t.Fatalf("mid scroll: off=%d", off)
	}

	// Tail reached: offset == maxOffset == 5.
	off, _, _ = m.step("row", nameLen, budget, t0.Add(marqueeHoldStart+5*marqueeStep+time.Millisecond))
	if off != 5 {
		t.Fatalf("tail: off=%d", off)
	}

	// Hold-end window still pegged at maxOffset.
	off, _, _ = m.step("row", nameLen, budget, t0.Add(marqueeHoldStart+5*marqueeStep+marqueeHoldEnd/2))
	if off != 5 {
		t.Fatalf("hold-end mid: off=%d", off)
	}

	// After hold-end: snap back to offset 0.
	off, _, _ = m.step("row", nameLen, budget, t0.Add(marqueeHoldStart+5*marqueeStep+marqueeHoldEnd+time.Millisecond))
	if off != 0 {
		t.Fatalf("snap back: off=%d", off)
	}
}

func TestMarqueeIDChangeResets(t *testing.T) {
	var m marqueeState
	t0 := time.Unix(0, 0)
	_, _, _ = m.step("a", 10, 5, t0)
	// Advance well into scroll for row "a".
	_, _, _ = m.step("a", 10, 5, t0.Add(marqueeHoldStart+3*marqueeStep))
	// Now focus moves to "b": offset must reset to 0 and phase to hold-start.
	off, anim, wake := m.step("b", 10, 5, t0.Add(marqueeHoldStart+3*marqueeStep))
	if off != 0 || !anim || wake != marqueeHoldStart {
		t.Fatalf("id reset: off=%d anim=%v wake=%v", off, anim, wake)
	}
}

func TestMarqueeActive(t *testing.T) {
	var m marqueeState
	if m.active() {
		t.Fatalf("fresh marquee should not be active")
	}
	_, _, _ = m.step("row", 10, 5, time.Unix(0, 0))
	if !m.active() {
		t.Fatalf("expected active after overflow step")
	}
	_, _, _ = m.step("row", 4, 5, time.Unix(0, 0))
	if m.active() {
		t.Fatalf("should not be active when name fits")
	}
}

func TestMarqueeReset(t *testing.T) {
	var m marqueeState
	_, _, _ = m.step("row", 10, 5, time.Unix(0, 0))
	m.reset()
	if m.active() {
		t.Fatalf("expected inactive after reset")
	}
	// After reset, stepping the same id starts fresh.
	off, _, wake := m.step("row", 10, 5, time.Unix(5, 0))
	if off != 0 || wake != marqueeHoldStart {
		t.Fatalf("post-reset start: off=%d wake=%v", off, wake)
	}
}

func TestFitName(t *testing.T) {
	cases := []struct {
		name, in string
		budget   int
		want     string
	}{
		{"fits", "abc", 5, "abc"},
		{"exact", "abcde", 5, "abcde"},
		{"truncate", "abcdef", 5, "abcd…"},
		{"budget1", "abcdef", 1, "…"},
		{"budget0", "abc", 0, ""},
		{"unicode", "αβγδεζη", 4, "αβγ…"},
	}
	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			got := fitName(c.in, c.budget)
			if got != c.want {
				t.Fatalf("fitName(%q, %d) = %q want %q", c.in, c.budget, got, c.want)
			}
		})
	}
}

func TestMarqueeWindow(t *testing.T) {
	got := marqueeWindow("abcdefgh", 4, 2)
	if got != "cdef" {
		t.Fatalf("window = %q", got)
	}
	// Clamp end-of-string overflow.
	got = marqueeWindow("abcdef", 4, 10)
	if got != "cdef" {
		t.Fatalf("clamped window = %q", got)
	}
}

func TestClampVisible(t *testing.T) {
	// Plain string longer than width.
	if got := clampVisible("abcdef", 3); visibleLen(got) != 3 {
		t.Fatalf("plain clamp visible = %d (%q)", visibleLen(got), got)
	}
	// Already-fitting string is unchanged.
	if got := clampVisible("abc", 5); got != "abc" {
		t.Fatalf("unchanged = %q", got)
	}
	// SGR-wrapped string: visible portion must be <= width.
	in := "\x1b[1mhello\x1b[0m world"
	got := clampVisible(in, 5)
	if visibleLen(got) != 5 {
		t.Fatalf("sgr clamp visible = %d (%q)", visibleLen(got), got)
	}
}