//! Apple Podcasts' categories, and where a feed's category sits among them (#118).

/// Apple's podcast categories, each with its subcategories
/// (https://podcasters.apple.com/support/1691-apple-podcasts-categories): the list a podcast's own
/// `<itunes:category>` comes from, and a fixed one, so the Directory's categories stay few.
pub(crate) const CATEGORIES: &[(&str, &[&str])] = &[
    ("Arts", &["Books", "Design", "Fashion & Beauty", "Food", "Performing Arts", "Visual Arts"]),
    ("Business", &["Careers", "Entrepreneurship", "Investing", "Management", "Marketing", "Non-Profit"]),
    ("Comedy", &["Comedy Interviews", "Improv", "Stand-Up"]),
    ("Education", &["Courses", "How To", "Language Learning", "Self-Improvement"]),
    ("Fiction", &["Comedy Fiction", "Drama", "Science Fiction"]),
    ("Government", &[]),
    ("History", &[]),
    ("Health & Fitness", &["Alternative Health", "Fitness", "Medicine", "Mental Health", "Nutrition", "Sexuality"]),
    ("Kids & Family", &["Education for Kids", "Parenting", "Pets & Animals", "Stories for Kids"]),
    (
        "Leisure",
        &["Animation & Manga", "Automotive", "Aviation", "Crafts", "Games", "Hobbies", "Home & Garden", "Video Games"],
    ),
    ("Music", &["Music Commentary", "Music History", "Music Interviews"]),
    (
        "News",
        &[
            "Business News",
            "Daily News",
            "Entertainment News",
            "News Commentary",
            "Politics",
            "Sports News",
            "Tech News",
        ],
    ),
    (
        "Religion & Spirituality",
        &["Buddhism", "Christianity", "Hinduism", "Islam", "Judaism", "Religion", "Spirituality"],
    ),
    (
        "Science",
        &[
            "Astronomy",
            "Chemistry",
            "Earth Sciences",
            "Life Sciences",
            "Mathematics",
            "Natural Sciences",
            "Nature",
            "Physics",
            "Social Sciences",
        ],
    ),
    ("Society & Culture", &["Documentary", "Personal Journals", "Philosophy", "Places & Travel", "Relationships"]),
    (
        "Sports",
        &[
            "Baseball",
            "Basketball",
            "Cricket",
            "Fantasy Sports",
            "Football",
            "Golf",
            "Hockey",
            "Rugby",
            "Running",
            "Soccer",
            "Swimming",
            "Tennis",
            "Volleyball",
            "Wilderness",
            "Wrestling",
        ],
    ),
    ("Technology", &[]),
    ("True Crime", &[]),
    ("TV & Film", &["After Shows", "Film History", "Film Interviews", "Film Reviews", "TV Reviews"]),
];

/// Names that are not in Apple's list but mean one that is (#125). Jev picked from this list when
/// it spelt Football and Soccer its own way, and stored those answers; Software How-To is Apple's
/// Technology subcategory from before its 2019 list, which older feeds still name.
pub(crate) const ALIASES: &[(&str, &str)] =
    &[("American Football", "Football"), ("Football (Soccer)", "Soccer"), ("Software How-To", "Technology")];

/// Apple's categories as ipx has them, for the directory to check against Apple's own (#252).
#[must_use]
pub fn categories() -> &'static [(&'static str, &'static [&'static str])] {
    CATEGORIES
}

/// Where a category sits in Apple's list, as (category, subcategory), so the Directory browses a
/// category and then its subcategories as Apple's does (#118). A podcast's own is stored as its
/// subcategory, and one an admin typed that is not Apple's stands as a category of its own.
#[must_use]
pub fn category_path(name: &str) -> (String, Option<String>) {
    // A feed's own text, which can end in a stray comma: "Soccer," was a category of its own.
    let name = name.trim().trim_end_matches([',', ';', '.']).trim_end();
    let name = ALIASES.iter().find(|(old, _)| old.eq_ignore_ascii_case(name)).map_or(name, |(_, now)| now);
    for (category, subs) in CATEGORIES {
        if category.eq_ignore_ascii_case(name) {
            return (category.to_string(), None);
        }
        if let Some(sub) = subs.iter().find(|s| s.eq_ignore_ascii_case(name)) {
            return (category.to_string(), Some(sub.to_string()));
        }
    }
    (name.to_string(), None)
}

#[cfg(test)]
mod tests {

    #[test]
    fn category_path_finds_a_subcategory_s_category() {
        use super::category_path;
        assert_eq!(category_path("Tech News"), ("News".into(), Some("Tech News".into())));
        assert_eq!(category_path("video games"), ("Leisure".into(), Some("Video Games".into())), "Apple's spelling");
        assert_eq!(category_path("Technology"), ("Technology".into(), None));
        assert_eq!(category_path("Homebrew"), ("Homebrew".into(), None), "not Apple's: its own category");
        // Apple's spelling, an old answer of Jev's, a stray comma and Apple's old list (#125).
        assert_eq!(category_path("Soccer"), ("Sports".into(), Some("Soccer".into())));
        assert_eq!(category_path("Football (Soccer)"), ("Sports".into(), Some("Soccer".into())));
        assert_eq!(category_path("Soccer,"), ("Sports".into(), Some("Soccer".into())));
        assert_eq!(category_path("Football"), ("Sports".into(), Some("Football".into())));
        assert_eq!(category_path("Software How-To"), ("Technology".into(), None));
    }
}