coyote/routes/status.cpp

#include "routes.h"
#include "../lxb_wrapper.h"
#include "../servehelper.h"
#include "../client.h"
#include "../models.h"

static inline std::string make_title(const Post& post);
static inline Nodes generate_ogp_nodes(const httplib::Request& req, const Post& post, const std::string& server);
static inline void generate_media_ogp_nodes(Nodes& nodes, const Media& media, bool* has_video, bool* has_image);


void status_route(const httplib::Request& req, httplib::Response& res) {
    std::string server = req.matches.str(1);
    std::string id = req.matches.str(2);

    std::optional<Post> post;
    PostContext context;
    try {
        post = mastodon_client.get_post(server, id);
        if (post) {
            context = mastodon_client.get_post_context(server, id);
        }
    } catch (const std::exception& e) {
        res.status = 500;
        serve_error(req, res, "500: Internal server error", "Failed to fetch post information", e.what());
        return;
    }

    if (!post) {
        res.status = 404;
        serve_error(req, res, "404: Post not found");
        return;
    }

    // https://dlx.pink/notice/AbtdJkjioOo8ZSdDhw
    if (post->reblog && !post->reblog->account.id.empty()) {
        serve_redirect(req, res, get_origin(req) + '/' + server + "/@" + post->reblog->account.acct(false) + '/' + post->reblog->id, true);
        return;
    }

    Element body("body");
    body.nodes.reserve(context.ancestors.size() * 2 + 1 + context.descendants.size() * 2);

    for (const Post& i : context.ancestors) {
        body.nodes.push_back(serialize_post(req, server, i));
        body.nodes.push_back(Element("hr"));
    }
    body.nodes.push_back(serialize_post(req, server, *post, false, true));
    for (const Post& i : context.descendants) {
        body.nodes.push_back(Element("hr"));
        body.nodes.push_back(serialize_post(req, server, i));
    }

    serve(req, res, make_title(*post), std::move(body), generate_ogp_nodes(req, *post, server));
}


static inline std::string make_title(const Post& post) {
    LXB::HTML::Document document(post.content.str);
    size_t content_len;
    const char* content = reinterpret_cast<const char*>(lxb_dom_node_text_content(document.body(), &content_len));

    std::string title = post.account.display_name + " (@" + post.account.acct() + "): ";
    if (content_len) {
        title.append(content, content_len > 50 ? 50 : content_len);
        if (content_len > 50) {
            title += "…";
        }
    } else {
        title += "Post";
    }

    return title;
}

static inline Nodes generate_ogp_nodes(const httplib::Request& req, const Post& post, const std::string& server) {
    using namespace std::string_literals;
    std::string url = get_origin(req) + '/' + server + "/@" + post.account.acct(false) + '/' + post.id;
    bool has_video = false, has_image = false;

    Nodes nodes({
        // left-to-right override--thank https://anarres.family/@alice@mk.nyaa.place
        Element("meta", {{"property", "og:title"}, {"content", post.account.display_name + "\u202d (@" + post.account.acct() + ')'}}, {}),
        Element("meta", {{"property", "og:site_name"}, {"content", "Coyote"}}, {}),
        Element("meta", {{"property", "og:url"}, {"content", std::move(url)}}, {}),
    });
    if (!post.sensitive) {
        nodes.push_back(Element("meta", {{"property", "og:description"}, {"content", get_text_content(post.content)}}, {}));

        for (const Media& media : post.media_attachments) {
            generate_media_ogp_nodes(nodes, media, &has_video, &has_image);
        }
    } else if (!post.spoiler_text.empty()) {
        nodes.push_back(Element("meta", {{"property", "og:description"}, {"content", "CW: "s + post.spoiler_text}}, {}));
    }

    const char* type = !post.sensitive && has_video
        ? "video"
        : !post.sensitive && has_image ? "photo" : "article";
    nodes.push_back(Element("meta", {{"property", "og:type"}, {"content", type}}, {}));

    return nodes;
}

static inline void generate_media_ogp_nodes(Nodes& nodes, const Media& media, bool* has_video, bool* has_image) {
    if (media.type == "image") {
        *has_image = true;
        nodes.push_back(Element("meta", {{"property", "og:image"}, {"content", media.preview_url.value_or(media.url)}}, {}));

        std::optional<Size> size = media.preview_size ? media.preview_size : media.size;
        if (size) {
            nodes.push_back(Element("meta", {{"property", "og:image:width"}, {"content", std::to_string(size->width)}}, {}));
            nodes.push_back(Element("meta", {{"property", "og:image:height"}, {"content", std::to_string(size->height)}}, {}));
        }

        if (media.description) {
            nodes.push_back(Element("meta", {{"property", "og:image:alt"}, {"content", *media.description}}, {}));
        }
    } else if (media.type == "video" || media.type == "gifv") {
        *has_video = true;
        nodes.push_back(Element("meta", {{"property", "og:video"}, {"content", media.preview_url.value_or(media.url)}}, {}));

        std::optional<Size> size = media.preview_size ? media.preview_size : media.size;
        if (size) {
            nodes.push_back(Element("meta", {{"property", "og:video:width"}, {"content", std::to_string(size->width)}}, {}));
            nodes.push_back(Element("meta", {{"property", "og:video:height"}, {"content", std::to_string(size->height)}}, {}));
        }

        if (media.description) {
            nodes.push_back(Element("meta", {{"property", "og:video:alt"}, {"content", *media.description}}, {}));
        }
    } else if (media.type == "audio") {
        nodes.push_back(Element("meta", {{"property", "og:audio"}, {"content", media.url}}, {}));
    }
}