use std::marker::PhantomData;
use std::path::PathBuf;

use gpui3::Div;

use crate::prelude::*;
use crate::{h_stack, HighlightedText};

#[derive(Clone)]
pub struct Symbol(pub Vec<HighlightedText>);

#[derive(Element)]
pub struct Breadcrumb<S: 'static + Send + Sync + Clone> {
    state_type: PhantomData<S>,
    path: PathBuf,
    symbols: Vec<Symbol>,
}

impl<S: 'static + Send + Sync + Clone> Breadcrumb<S> {
    pub fn new(path: PathBuf, symbols: Vec<Symbol>) -> Self {
        Self {
            state_type: PhantomData,
            path,
            symbols,
        }
    }

    fn render_separator(&self, theme: &Theme) -> Div<S> {
        div()
            .child(" › ")
            .text_color(HighlightColor::Default.hsla(theme))
    }

    fn render(
        &mut self,
        view_state: &mut S,
        cx: &mut ViewContext<S>,
    ) -> impl Element<ViewState = S> {
        let theme = theme(cx);

        let symbols_len = self.symbols.len();

        h_stack()
            .px_1()
            // TODO: Read font from theme (or settings?).
            .font("Zed Mono Extended")
            .text_sm()
            .text_color(theme.middle.base.default.foreground)
            .rounded_md()
            .hover(|style| style.bg(theme.highest.base.hovered.background))
            .child(self.path.clone().to_str().unwrap().to_string())
            .child(if !self.symbols.is_empty() {
                self.render_separator(&theme)
            } else {
                div()
            })
            .child(
                div().flex().children(
                    self.symbols
                        .iter()
                        .enumerate()
                        // TODO: Could use something like `intersperse` here instead.
                        .flat_map(|(ix, symbol)| {
                            let mut items =
                                vec![div().flex().children(symbol.0.iter().map(|segment| {
                                    div().child(segment.text.clone()).text_color(segment.color)
                                }))];

                            let is_last_segment = ix == symbols_len - 1;
                            if !is_last_segment {
                                items.push(self.render_separator(&theme));
                            }

                            items
                        })
                        .collect::<Vec<_>>(),
                ),
            )
    }
}

#[cfg(feature = "stories")]
pub use stories::*;

#[cfg(feature = "stories")]
mod stories {
    use std::str::FromStr;

    use crate::Story;

    use super::*;

    #[derive(Element)]
    pub struct BreadcrumbStory<S: 'static + Send + Sync + Clone> {
        state_type: PhantomData<S>,
    }

    impl<S: 'static + Send + Sync + Clone> BreadcrumbStory<S> {
        pub fn new() -> Self {
            Self {
                state_type: PhantomData,
            }
        }

        fn render(
            &mut self,
            view_state: &mut S,
            cx: &mut ViewContext<S>,
        ) -> impl Element<ViewState = S> {
            let theme = theme(cx);

            Story::container(cx)
                .child(Story::title_for::<_, Breadcrumb<S>>(cx))
                .child(Story::label(cx, "Default"))
                .child(Breadcrumb::new(
                    PathBuf::from_str("crates/ui/src/components/toolbar.rs").unwrap(),
                    vec![
                        Symbol(vec![
                            HighlightedText {
                                text: "impl ".to_string(),
                                color: HighlightColor::Keyword.hsla(&theme),
                            },
                            HighlightedText {
                                text: "BreadcrumbStory".to_string(),
                                color: HighlightColor::Function.hsla(&theme),
                            },
                        ]),
                        Symbol(vec![
                            HighlightedText {
                                text: "fn ".to_string(),
                                color: HighlightColor::Keyword.hsla(&theme),
                            },
                            HighlightedText {
                                text: "render".to_string(),
                                color: HighlightColor::Function.hsla(&theme),
                            },
                        ]),
                    ],
                ))
        }
    }
}