//! Provider tabs component for multi-LLM support
//!
//! Displays horizontal tabs for switching between providers (Claude, Ollama, OpenAI)
//! with icons and keybind hints.

use crate::theme::{Provider, Theme};
use ratatui::{
    layout::Rect,
    style::Style,
    text::{Line, Span},
    widgets::Paragraph,
    Frame,
};

/// Provider tab state and rendering
pub struct ProviderTabs {
    active: Provider,
    theme: Theme,
}

impl ProviderTabs {
    /// Create new provider tabs with default provider
    pub fn new(theme: Theme) -> Self {
        Self {
            active: Provider::Ollama, // Default to Ollama (local)
            theme,
        }
    }

    /// Create with specific active provider
    pub fn with_provider(provider: Provider, theme: Theme) -> Self {
        Self {
            active: provider,
            theme,
        }
    }

    /// Get the currently active provider
    pub fn active(&self) -> Provider {
        self.active
    }

    /// Set the active provider
    pub fn set_active(&mut self, provider: Provider) {
        self.active = provider;
    }

    /// Cycle to the next provider
    pub fn next(&mut self) {
        self.active = match self.active {
            Provider::Claude => Provider::Ollama,
            Provider::Ollama => Provider::OpenAI,
            Provider::OpenAI => Provider::Claude,
        };
    }

    /// Cycle to the previous provider
    pub fn previous(&mut self) {
        self.active = match self.active {
            Provider::Claude => Provider::OpenAI,
            Provider::Ollama => Provider::Claude,
            Provider::OpenAI => Provider::Ollama,
        };
    }

    /// Select provider by number (1, 2, 3)
    pub fn select_by_number(&mut self, num: u8) {
        self.active = match num {
            1 => Provider::Claude,
            2 => Provider::Ollama,
            3 => Provider::OpenAI,
            _ => self.active,
        };
    }

    /// Update the theme
    pub fn set_theme(&mut self, theme: Theme) {
        self.theme = theme;
    }

    /// Render the provider tabs (borderless)
    pub fn render(&self, frame: &mut Frame, area: Rect) {
        let mut spans = Vec::new();

        // Add spacing at start
        spans.push(Span::raw("  "));

        for (i, provider) in Provider::all().iter().enumerate() {
            let is_active = *provider == self.active;
            let icon = self.theme.provider_icon(*provider);
            let name = provider.name();
            let number = (i + 1).to_string();

            // Keybind hint
            spans.push(Span::styled(
                format!("[{}] ", number),
                self.theme.status_dim,
            ));

            // Icon and name
            let style = if is_active {
                Style::default()
                    .fg(self.theme.provider_color(*provider))
                    .add_modifier(ratatui::style::Modifier::BOLD)
            } else {
                self.theme.tab_inactive
            };

            spans.push(Span::styled(format!("{} ", icon), style));
            spans.push(Span::styled(name.to_string(), style));

            // Separator between tabs (not after last)
            if i < Provider::all().len() - 1 {
                spans.push(Span::styled(
                    format!("  {}  ", self.theme.symbols.vertical_separator),
                    self.theme.status_dim,
                ));
            }
        }

        // Tab cycling hint on the right
        spans.push(Span::raw("  "));
        spans.push(Span::styled("[Tab] cycle", self.theme.status_dim));

        let line = Line::from(spans);
        let paragraph = Paragraph::new(line);
        frame.render_widget(paragraph, area);
    }

    /// Render a compact version (just active provider)
    pub fn render_compact(&self, frame: &mut Frame, area: Rect) {
        let icon = self.theme.provider_icon(self.active);
        let name = self.active.name();

        let line = Line::from(vec![
            Span::raw("  "),
            Span::styled(
                format!("{} {}", icon, name),
                Style::default()
                    .fg(self.theme.provider_color(self.active))
                    .add_modifier(ratatui::style::Modifier::BOLD),
            ),
        ]);

        let paragraph = Paragraph::new(line);
        frame.render_widget(paragraph, area);
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_provider_cycling() {
        let theme = Theme::default();
        let mut tabs = ProviderTabs::new(theme);

        assert_eq!(tabs.active(), Provider::Ollama);

        tabs.next();
        assert_eq!(tabs.active(), Provider::OpenAI);

        tabs.next();
        assert_eq!(tabs.active(), Provider::Claude);

        tabs.next();
        assert_eq!(tabs.active(), Provider::Ollama);
    }

    #[test]
    fn test_select_by_number() {
        let theme = Theme::default();
        let mut tabs = ProviderTabs::new(theme);

        tabs.select_by_number(1);
        assert_eq!(tabs.active(), Provider::Claude);

        tabs.select_by_number(2);
        assert_eq!(tabs.active(), Provider::Ollama);

        tabs.select_by_number(3);
        assert_eq!(tabs.active(), Provider::OpenAI);

        // Invalid number should not change
        tabs.select_by_number(4);
        assert_eq!(tabs.active(), Provider::OpenAI);
    }
}