package tui

import (
    "testing"
)

func TestLastAssistantContent(t *testing.T) {
    t.Run("found", func(t *testing.T) {
        m := newTestModel(t)
        m.entries = []ChatEntry{
            {Kind: "user", Content: "hello"},
            {Kind: "assistant", Content: "world"},
        }
        got := m.lastAssistantContent()
        if got != "world" {
            t.Errorf("expected 'world', got %q", got)
        }
    })

    t.Run("not_found", func(t *testing.T) {
        m := newTestModel(t)
        m.entries = []ChatEntry{
            {Kind: "user", Content: "hello"},
            {Kind: "system", Content: "info"},
        }
        got := m.lastAssistantContent()
        if got != "" {
            t.Errorf("expected empty string, got %q", got)
        }
    })

    t.Run("returns_last", func(t *testing.T) {
        m := newTestModel(t)
        m.entries = []ChatEntry{
            {Kind: "assistant", Content: "first"},
            {Kind: "user", Content: "question"},
            {Kind: "assistant", Content: "second"},
        }
        got := m.lastAssistantContent()
        if got != "second" {
            t.Errorf("expected 'second', got %q", got)
        }
    })

    t.Run("empty_entries", func(t *testing.T) {
        m := newTestModel(t)
        m.entries = nil
        got := m.lastAssistantContent()
        if got != "" {
            t.Errorf("expected empty string, got %q", got)
        }
    })
}

func TestCopyLast_OnlyWhenIdleAndEmpty(t *testing.T) {
    t.Run("idle_empty_with_assistant", func(t *testing.T) {
        m := newTestModel(t)
        m.state = StateIdle
        m.entries = []ChatEntry{
            {Kind: "assistant", Content: "response text"},
        }
        m.input.SetValue("")

        _, cmd := m.Update(ctrlKey('y'))
        if cmd == nil {
            t.Error("expected a command to be returned for copy")
        }
    })

    t.Run("non_empty_input_no_trigger", func(t *testing.T) {
        m := newTestModel(t)
        m.state = StateIdle
        m.entries = []ChatEntry{
            {Kind: "assistant", Content: "response text"},
        }
        m.input.SetValue("some text")

        _, cmd := m.Update(ctrlKey('y'))
        // When input is non-empty, ctrl+y should not trigger copy.
        // The cmd may be non-nil (textarea update), but no copy should occur.
        // Verify no system message about clipboard appears.
        if cmd != nil {
            msg := cmd()
            if sysMsg, ok := msg.(SystemMessageMsg); ok {
                if sysMsg.Msg == "Copied to clipboard." {
                    t.Error("should not trigger copy when input is non-empty")
                }
            }
        }
    })

    t.Run("non_idle_no_trigger", func(t *testing.T) {
        m := newTestModel(t)
        m.state = StateStreaming
        m.entries = []ChatEntry{
            {Kind: "assistant", Content: "response text"},
        }
        m.input.SetValue("")

        initialEntryCount := len(m.entries)
        m.Update(ctrlKey('y'))
        // Should not add any system message about clipboard
        if len(m.entries) > initialEntryCount {
            t.Error("should not trigger copy when not idle")
        }
    })

    t.Run("no_assistant_entries", func(t *testing.T) {
        m := newTestModel(t)
        m.state = StateIdle
        m.entries = []ChatEntry{
            {Kind: "user", Content: "hello"},
        }
        m.input.SetValue("")

        _, cmd := m.Update(ctrlKey('y'))
        // Should not return a copy command when there's no assistant content
        if cmd != nil {
            msg := cmd()
            if sysMsg, ok := msg.(SystemMessageMsg); ok {
                if sysMsg.Msg == "Copied to clipboard." {
                    t.Error("should not trigger copy when no assistant content")
                }
            }
        }
    })
}