import common


def links_to_nearby_entries(id):
    earlier_entries = [
        e for e in reversed(list(common.entries)[: list(common.entries).index(id)])
    ]
    later_entries = [
        e for e in list(common.entries)[1 + list(common.entries).index(id) :]
    ]
    relevant_earlier_entries = {}
    relevant_later_entries = {}
    for other_entry in earlier_entries:
        if earlier_entries.index(other_entry) == 0:
            relevant_earlier_entries[other_entry] = relevant_earlier_entries.get(
                other_entry, {}
            )
            relevant_earlier_entries[other_entry].update({"rel": "prev"})
        if "series" in common.entries[id] and "series" in common.entries[other_entry]:
            if common.slugify(common.entries[id]["series"]) == common.slugify(
                common.entries[other_entry]["series"]
            ):
                if other_entry == common.offset_id(
                    common.entries_in_series(common.entries[id]["series"]), id, -1
                ):
                    relevant_earlier_entries[
                        other_entry
                    ] = relevant_earlier_entries.get(other_entry, {})
                    relevant_earlier_entries[other_entry].update({"rel": "prev"})
        if "tags" in common.entries[id] and "tags" in common.entries[other_entry]:
            for tag_string in [
                tag_string
                for tag_string in common.entries[id]["tags"]
                if common.slugify(tag_string)
                in map(common.slugify, common.entries[other_entry]["tags"])
            ]:
                entries_with_this_tag = common.entries_with_tag(tag_string)
                if other_entry == common.offset_id(entries_with_this_tag, id, -1):
                    relevant_earlier_entries[
                        other_entry
                    ] = relevant_earlier_entries.get(other_entry, {})
                    relevant_earlier_entries[other_entry][
                        "labels"
                    ] = relevant_earlier_entries[other_entry].get("labels", [])
                    relevant_earlier_entries[other_entry]["labels"] += [tag_string]
                    relevant_earlier_entries[other_entry].update({"rel": "prev"})
    for other_entry in later_entries:
        if later_entries.index(other_entry) == 0:
            relevant_later_entries[other_entry] = relevant_later_entries.get(
                other_entry, {}
            )
            relevant_later_entries[other_entry].update({"rel": "next"})
        if "series" in common.entries[id] and "series" in common.entries[other_entry]:
            if common.slugify(common.entries[id]["series"]) == common.slugify(
                common.entries[other_entry]["series"]
            ):
                if other_entry == common.offset_id(
                    common.entries_in_series(common.entries[id]["series"]), id, +1
                ):
                    relevant_later_entries[other_entry] = relevant_later_entries.get(
                        other_entry, {}
                    )
                    relevant_later_entries[other_entry].update({"rel": "next"})
        if "tags" in common.entries[id] and "tags" in common.entries[other_entry]:
            for tag_string in [
                tag_string
                for tag_string in common.entries[id]["tags"]
                if common.slugify(tag_string)
                in map(common.slugify, common.entries[other_entry]["tags"])
            ]:
                entries_with_this_tag = common.entries_with_tag(tag_string)
                if other_entry == common.offset_id(entries_with_this_tag, id, +1):
                    relevant_later_entries[other_entry] = relevant_later_entries.get(
                        other_entry, {}
                    )
                    relevant_later_entries[other_entry][
                        "labels"
                    ] = relevant_later_entries[other_entry].get("labels", [])
                    relevant_later_entries[other_entry]["labels"] += [tag_string]
                    relevant_later_entries[other_entry].update({"rel": "next"})
    links = ""
    if len(relevant_earlier_entries) > 0:
        links += (
            "<h2>Earlier:</h2>"
            + "<ul>"
            + "".join(
                "<li>"
                + common.link_to_entry(other_id, **relevant_earlier_entries[other_id])
                + "</li>"
                for other_id in relevant_earlier_entries
            )
            + "</ul>"
        )
    if len(relevant_later_entries) > 0:
        links += (
            "<h2>Later:</h2>"
            + "<ul>"
            + "".join(
                "<li>"
                + common.link_to_entry(other_id, **relevant_later_entries[other_id])
                + "</li>"
                for other_id in relevant_later_entries
            )
            + "</ul>"
        )
    return links


def html(entries, id):
    entry = entries[id]
    byline = (
        (
            '<div class="series">'
            + "from "
            + f'<a href="{common.url_of_series(entry["series"])}">'
            + entry["series"]
            + "</a>"
            + "</div>"
            if "series" in entry
            else ""
        )
        + '<div class="byline">'
        + 'by <a href="/">Grey Nicholson</a>'
        + "</div>"
        + '<div class="datestamp">'
        + ("published " if "modified" in entry else "")
        + f'<time datetime="{entry["date"]:%Y-%m-%dT%H:%MZ}">'
        f'{entry["date"]:%Y-%m-%d}'
        " · "
        f'stardate {common.stardate(entry["date"])}'
        "</time>"
        + (
            "<div>"
            + "edited "
            + f'<time datetime="{entry["modified"]:%Y-%m-%dT%H:%MZ}">'
            + f'{entry["modified"]:%Y-%m-%d}'
            + " · "
            + f'stardate {common.stardate(entry["modified"])}'
            + "</time>"
            + "</div>"
            if "modified" in entry
            else ""
        )
        + "</div>"
    )
    colour_class = (
        common.slugify(entry["series"])
        if "series" in entry
        else f'month-{entry["date"].month:02d}'
    )
    decoration = (
        f"""<div class="decoration" style="background-image: url('{entry["image"]["filename"]}');"""
        + (
            f""" background-position: {entry["image"]["position"]};"""
            if "position" in entry["image"]
            else ""
        )
        + (
            f""" height: {entry["image"]["height"]};"""
            if "height" in entry["image"]
            else ""
        )
        + '"></div>'
        if "image" in entry
        else '<div class="decoration"></div>'
        if "series" in entry
        else ""
    )
    description = (
        (
            '<div class="description">'
            + common.convert_to_html(entry["description"])
            + "</div>"
        )
        if "description" in entry
        else ""
    )
    entry_links = (
        (
            "<hr/>"
            + "<nav>"
            + "<h2>See also:</h2>"
            + "<ul>"
            + "".join(
                ("<li>" + common.link_with_details(**link) + "</li>")
                for link in entry["links"]
            )
            + "</ul>"
            + "</nav>"
        )
        if "links" in entry
        else ""
    )

    repeated_tags = (
        list(
            common.slugify(tag)
            for tag in entry["tags"]
            if common.slugify(tag) in common.repeated_tags
        )
        if "tags" in entry
        else []
    )
    head = "".join(
        f"""<link href="{common.url_of_tag_feed(tag)}" rel="alternate" type="application/atom+xml" title="{common.title(tag)}">"""
        + "\n"
        for tag in repeated_tags
    )
    small = "<p><small>" + entry["small"] + "</small></p>" if "small" in entry else ""
    tags = (
        (
            '<div class="tags">tags: '
            + ", ".join(
                f'<a href="{common.url_of_tag(tag)}" rel="tag">' + tag + "</a>"
                for tag in repeated_tags
            )
            + "</ul>"
            + "</div>"
        )
        if repeated_tags
        else ""
    )
    tags = ""  # No tags for now

    return common.print_html(
        f"""<!doctype html>
            <html>
                <head>
                    {common.head}
                    {head}
                    <title>{entry['title']}</title>
                </head>
                <body class="entry {colour_class}">
                    <article>
                        <header>
                            {decoration}
                            <h1>{entry['title']}</h1>
                        </header>
                        <main>
                            <hr/>
                            <section>
                                {common.convert_to_html(entry.content)}
                            </section>
                            <footer>
                                <hr/>
                                <section>
                                    {byline}
                                    {description}
                                    {tags}
                                    {small}
                                </section>
                                {entry_links}
                            </footer>
                        </main>
                    </article>
                    <footer>
                        <hr/>
                        <nav>
                            {links_to_nearby_entries(id)}
                        </nav>
                    </footer>
                    {common.footer}
                </body>
            </html>
        """
    )