use crate::models::{ChatMessage, ChatRole};
use dioxus::prelude::*;

/// Render markdown content to HTML using `pulldown-cmark`.
///
/// # Arguments
///
/// * `md` - Raw markdown string
///
/// # Returns
///
/// HTML string suitable for `dangerous_inner_html`
fn markdown_to_html(md: &str) -> String {
    use pulldown_cmark::{Options, Parser};

    let mut opts = Options::empty();
    opts.insert(Options::ENABLE_TABLES);
    opts.insert(Options::ENABLE_STRIKETHROUGH);
    opts.insert(Options::ENABLE_TASKLISTS);

    let parser = Parser::new_ext(md, opts);
    let mut html = String::with_capacity(md.len() * 2);
    pulldown_cmark::html::push_html(&mut html, parser);
    html
}

/// Renders a single chat message bubble with role-based styling.
///
/// User messages are displayed as plain text, right-aligned.
/// Assistant messages are rendered as markdown with `pulldown-cmark`.
/// System messages are hidden from the UI.
///
/// # Arguments
///
/// * `message` - The chat message to render
#[component]
pub fn ChatBubble(message: ChatMessage) -> Element {
    // System messages are not rendered in the UI
    if message.role == ChatRole::System {
        return rsx! {};
    }

    let bubble_class = match message.role {
        ChatRole::User => "chat-bubble chat-bubble--user",
        ChatRole::Assistant => "chat-bubble chat-bubble--assistant",
        ChatRole::System => unreachable!(),
    };

    let role_label = match message.role {
        ChatRole::User => "You",
        ChatRole::Assistant => "Assistant",
        ChatRole::System => unreachable!(),
    };

    // Format timestamp for display (show time only if today)
    let display_time = if message.timestamp.len() >= 16 {
        // Extract HH:MM from ISO 8601
        message.timestamp[11..16].to_string()
    } else {
        message.timestamp.clone()
    };

    let is_assistant = message.role == ChatRole::Assistant;

    rsx! {
        div { class: "{bubble_class}",
            div { class: "chat-bubble-header",
                span { class: "chat-bubble-role", "{role_label}" }
                span { class: "chat-bubble-time", "{display_time}" }
            }
            if is_assistant {
                // Render markdown for assistant messages
                div {
                    class: "chat-bubble-content chat-prose",
                    dangerous_inner_html: "{markdown_to_html(&message.content)}",
                }
            } else {
                div { class: "chat-bubble-content", "{message.content}" }
            }
            if !message.attachments.is_empty() {
                div { class: "chat-bubble-attachments",
                    for att in &message.attachments {
                        span { class: "chat-attachment", "{att.name}" }
                    }
                }
            }
        }
    }
}

/// Renders a streaming assistant message bubble.
///
/// While waiting for tokens, shows a "Thinking..." indicator with
/// a pulsing dot animation. Once tokens arrive, renders them as
/// markdown with a blinking cursor.
///
/// # Arguments
///
/// * `content` - The accumulated streaming content so far
#[component]
pub fn StreamingBubble(content: String) -> Element {
    if content.is_empty() {
        // Thinking state -- no tokens yet
        rsx! {
            div { class: "chat-bubble chat-bubble--assistant chat-bubble--thinking",
                div { class: "chat-thinking",
                    span { class: "chat-thinking-dots",
                        span { class: "chat-dot" }
                        span { class: "chat-dot" }
                        span { class: "chat-dot" }
                    }
                    span { class: "chat-thinking-text", "Thinking..." }
                }
            }
        }
    } else {
        let html = markdown_to_html(&content);
        rsx! {
            div { class: "chat-bubble chat-bubble--assistant chat-bubble--streaming",
                div { class: "chat-bubble-header",
                    span { class: "chat-bubble-role", "Assistant" }
                }
                div {
                    class: "chat-bubble-content chat-prose",
                    dangerous_inner_html: "{html}",
                }
                span { class: "chat-streaming-cursor" }
            }
        }
    }
}