package tui

import "testing"

func TestPushHistory_Basic(t *testing.T) {
    m := newTestModel(t)
    m.pushHistory("hello")
    m.pushHistory("world")

    if len(m.promptHistory) != 2 {
        t.Fatalf("expected 2 history entries, got %d", len(m.promptHistory))
    }
    if m.promptHistory[0] != "hello" || m.promptHistory[1] != "world" {
        t.Errorf("unexpected history: %v", m.promptHistory)
    }
}

func TestPushHistory_Empty(t *testing.T) {
    m := newTestModel(t)
    m.pushHistory("")
    if len(m.promptHistory) != 0 {
        t.Error("empty string should not be added to history")
    }
}

func TestPushHistory_DedupConsecutive(t *testing.T) {
    m := newTestModel(t)
    m.pushHistory("hello")
    m.pushHistory("hello")
    m.pushHistory("hello")

    if len(m.promptHistory) != 1 {
        t.Errorf("expected 1 entry after dedup, got %d", len(m.promptHistory))
    }
}

func TestPushHistory_DedupNonConsecutive(t *testing.T) {
    m := newTestModel(t)
    m.pushHistory("hello")
    m.pushHistory("world")
    m.pushHistory("hello")

    if len(m.promptHistory) != 3 {
        t.Errorf("non-consecutive duplicates should be kept, got %d", len(m.promptHistory))
    }
}

func TestPushHistory_CapAt100(t *testing.T) {
    m := newTestModel(t)
    for i := 0; i < 110; i++ {
        m.pushHistory(string(rune('a' + i%26)) + string(rune('0'+i/26)))
    }

    if len(m.promptHistory) > 100 {
        t.Errorf("history should be capped at 100, got %d", len(m.promptHistory))
    }
}

func TestNavigateHistory_EmptyHistory(t *testing.T) {
    m := newTestModel(t)
    if m.navigateHistory(-1) {
        t.Error("up on empty history should return false")
    }
    if m.navigateHistory(1) {
        t.Error("down on empty history should return false")
    }
}

func TestNavigateHistory_UpDown(t *testing.T) {
    m := newTestModel(t)
    m.pushHistory("first")
    m.pushHistory("second")
    m.pushHistory("third")

    // Set current input
    m.input.SetValue("current")

    // Press up: should go to "third" (most recent)
    if !m.navigateHistory(-1) {
        t.Fatal("up should succeed")
    }
    if m.input.Value() != "third" {
        t.Errorf("expected 'third', got %q", m.input.Value())
    }
    if m.historySaved != "current" {
        t.Errorf("current input should be saved, got %q", m.historySaved)
    }

    // Press up again: "second"
    if !m.navigateHistory(-1) {
        t.Fatal("up should succeed")
    }
    if m.input.Value() != "second" {
        t.Errorf("expected 'second', got %q", m.input.Value())
    }

    // Press up again: "first"
    if !m.navigateHistory(-1) {
        t.Fatal("up should succeed")
    }
    if m.input.Value() != "first" {
        t.Errorf("expected 'first', got %q", m.input.Value())
    }

    // Press up again: at oldest, should fail
    if m.navigateHistory(-1) {
        t.Error("up at oldest should return false")
    }

    // Press down: "second"
    if !m.navigateHistory(1) {
        t.Fatal("down should succeed")
    }
    if m.input.Value() != "second" {
        t.Errorf("expected 'second', got %q", m.input.Value())
    }

    // Press down: "third"
    if !m.navigateHistory(1) {
        t.Fatal("down should succeed")
    }
    if m.input.Value() != "third" {
        t.Errorf("expected 'third', got %q", m.input.Value())
    }

    // Press down past newest: restore saved input
    if !m.navigateHistory(1) {
        t.Fatal("down past newest should succeed")
    }
    if m.input.Value() != "current" {
        t.Errorf("expected restored 'current', got %q", m.input.Value())
    }
    if m.historyIndex != -1 {
        t.Errorf("historyIndex should be -1 after exiting history, got %d", m.historyIndex)
    }
}

func TestNavigateHistory_DownNotBrowsing(t *testing.T) {
    m := newTestModel(t)
    m.pushHistory("hello")

    // Down without first pressing up should return false
    if m.navigateHistory(1) {
        t.Error("down when not browsing should return false")
    }
}

func TestHistoryKey_OnlyWhenIdleAndEmpty(t *testing.T) {
    t.Run("idle_empty_with_history", func(t *testing.T) {
        m := newTestModel(t)
        m.pushHistory("hello")
        m.state = StateIdle
        m.overlay = OverlayNone

        updated, _ := m.Update(upKey())
        m = updated.(*Model)

        if m.input.Value() != "hello" {
            t.Errorf("up key should navigate history, got %q", m.input.Value())
        }
    })

    t.Run("idle_nonempty_no_history", func(t *testing.T) {
        m := newTestModel(t)
        m.pushHistory("hello")
        m.state = StateIdle
        m.overlay = OverlayNone
        m.input.SetValue("typing something")

        updated, _ := m.Update(upKey())
        m = updated.(*Model)

        // Should NOT navigate history when input has content and not already browsing
        if m.historyIndex != -1 {
            t.Error("up key should not navigate history when input is non-empty")
        }
    })

    t.Run("waiting_no_history", func(t *testing.T) {
        m := newTestModel(t)
        m.pushHistory("hello")
        m.state = StateWaiting

        updated, _ := m.Update(upKey())
        m = updated.(*Model)

        if m.historyIndex != -1 {
            t.Error("up key should not navigate history when not idle")
        }
    })

    t.Run("overlay_no_history", func(t *testing.T) {
        m := newTestModel(t)
        m.pushHistory("hello")
        m.state = StateIdle
        m.overlay = OverlayHelp

        updated, _ := m.Update(upKey())
        m = updated.(*Model)

        if m.historyIndex != -1 {
            t.Error("up key should not navigate history when overlay is open")
        }
    })
}

func TestHistoryKey_AlreadyBrowsing(t *testing.T) {
    m := newTestModel(t)
    m.pushHistory("first")
    m.pushHistory("second")
    m.state = StateIdle
    m.overlay = OverlayNone
    // Input must be empty to start browsing
    m.input.SetValue("")

    // Press up — enters history (input is empty, so allowed)
    updated, _ := m.Update(upKey())
    m = updated.(*Model)
    if m.input.Value() != "second" {
        t.Fatalf("expected 'second', got %q", m.input.Value())
    }

    // Now input is non-empty (from history), up should still work because historyIndex != -1
    updated, _ = m.Update(upKey())
    m = updated.(*Model)
    if m.input.Value() != "first" {
        t.Errorf("expected 'first', got %q", m.input.Value())
    }
}