use organic::types::StandardProperties;
use url::Url;

use super::get_web_path;
use super::macros::intermediate;

use super::IObject;
use crate::context::RenderContext;
use crate::error::CustomError;

#[derive(Debug, Clone)]
pub(crate) struct IRegularLink {
    pub(crate) raw_link: String,
    pub(crate) children: Vec<IObject>,
    pub(crate) target: LinkTarget,
    pub(crate) post_blank: organic::types::PostBlank,
}

intermediate!(
    IRegularLink,
    &'orig organic::types::RegularLink<'parse>,
    original,
    intermediate_context,
    {
        let children = {
            let mut ret = Vec::new();
            for obj in original.children.iter() {
                ret.push(IObject::new(intermediate_context.clone(), obj).await?);
            }
            ret
        };
        let raw_link = original.get_raw_link();
        let target = LinkTarget::from_string(&raw_link)?;
        Ok(IRegularLink {
            raw_link: raw_link.into_owned(),
            children,
            target,
            post_blank: original.get_post_blank(),
        })
    }
);

#[derive(Debug, Clone)]
pub(crate) enum LinkTarget {
    Raw(String),
    Post {
        post_id: Option<String>,
        subpath: String,
    },
}

impl LinkTarget {
    pub(crate) fn from_string<S: AsRef<str>>(input: S) -> Result<LinkTarget, CustomError> {
        fn impl_from_string(input: &str) -> Result<LinkTarget, CustomError> {
            let parsed = Url::parse(input);
            if let Err(url::ParseError::RelativeUrlWithoutBase) = parsed {
                // For URLs to targets.
                // TODO: This shouldn't be raw but instead a variant for targets.
                return Ok(LinkTarget::Raw(input.to_owned()));
            }
            let parsed = parsed?;
            match parsed.scheme() {
                "post" => {
                    let post_id = parsed.host_str().map(str::to_owned);
                    let subpath = {
                        let subpath = parsed.path();
                        if let Some(subpath) = subpath.strip_prefix('/') {
                            subpath
                        } else {
                            subpath
                        }
                    };
                    Ok(LinkTarget::Post {
                        post_id,
                        subpath: subpath.to_owned(),
                    })
                }
                _ => Ok(LinkTarget::Raw(input.to_owned())),
            }
        }
        impl_from_string(input.as_ref())
    }

    pub(crate) fn generate_final_target(
        &self,
        render_context: RenderContext<'_>,
    ) -> Result<Option<String>, CustomError> {
        match self {
            LinkTarget::Raw(raw_link) => Ok(Some(raw_link.clone())),
            LinkTarget::Post { post_id, subpath } => {
                let path = post_id
                    .as_ref()
                    .map(|post_id| {
                        let path_to_post = render_context
                            .config
                            .get_relative_path_to_post(post_id)
                            .join(subpath);
                        get_web_path(
                            render_context.config,
                            render_context.output_root_directory,
                            render_context.output_file,
                            path_to_post,
                        )
                    })
                    .map_or(Ok(None), |r| r.map(Some))?;
                Ok(path)
            }
        }
    }
}