package alibaba:fontkit;

interface commons {
    record font-key {
        weight: option<u16>,
        italic: option<bool>,
        stretch: option<u16>,
        family: string,
    }
}

interface fontkit-interface {
    use commons.{font-key};

    record name {
        id: u16,
        name: string,
        language-id: u16
    }
    record font-info {
        style-names: list<name>,
        names: list<name>,
        path: option<string>,
        key: font-key,
    }
    record line-metrics {
        position: s16,
        thickness: s16,
    }
    resource text-metrics {
        constructor(value: string);
        duplicate: func() -> text-metrics;
        width: func(font-size: f32, letter-spacing: f32) -> f32;
        height: func(font-size: f32, line-height: option<f32>) -> f32;
        ascender: func(font-size: f32) -> f32;
        line-gap: func() -> f32;
        units: func() -> f32;
        slice: func(start: u32, count: u32) -> text-metrics;
        value: func() -> string;
        is-rtl: func() -> bool;
        append: func(other: text-metrics);
        count: func() -> u32;
        /// replace this metrics with another, allowing fallback logic
        replace: func(other: text-metrics, fallback: bool);
        split-by-width: func(font-size: f32, letter-spacing: f32, width: f32) -> text-metrics;
        chars: func() -> list<char>;
    }
    resource glyph-bitmap {
        width: func() -> u32;
        height: func() -> u32;
        bitmap: func() -> list<u8>;
        x-min: func() -> f32;
        y-max: func() -> f32;
        stroke-x: func() -> f32;
        stroke-y: func() -> f32;
        stroke-bitmap: func() -> option<tuple<list<u8>, u32>>;
        advanced-x: func() -> f32;
        ascender: func() -> f32;
        descender: func() -> f32;
    }
    /// Instance of a single font
    resource font {
        /// Check if the font has valid data for a character
        has-glyph: func(c: char) -> bool;
        /// Output the svg path string of a glyph
        glyph-path-string: func(c: char) -> option<string>;
        /// Return the font buffer
        buffer: func() -> list<u8>;
        /// Return the path if this font is added from searching a path
        path: func() -> string;
        /// Return the key of this font
        key: func() -> font-key;
        /// Measure text using this font
        measure: func(text: string) -> result<text-metrics, string>;
        ascender: func() -> s16;
        descender: func() -> s16;
        units-per-em: func() -> u16;
        bitmap: func(c: char, font-size: f32, stroke-width: f32) -> option<glyph-bitmap>;
        underline-metrics: func() -> option<line-metrics>;
        variation: func() -> option<list<tuple<string, f32>>>;
    }
    /// Stores font buffer and provides font-querying APIs
    resource font-kit {
        constructor();
        /// Register a font (or several fonts in case of ttc), return the keys of added fonts.
        /// The file type is extracted from the buffer by checking magic numbers
        add-font-from-buffer: func(buffer: list<u8>) -> list<font-key>;
        /// Search and add fonts from a path
        add-search-path: func(path: string);
        /// Query font using a key, this API returns valid result only if a single result is found
        query: func(key: font-key) -> option<font>;
        /// Using exact-match method to directly obtain a font, skipping the querying logic
        exact-match: func(key: font-key) -> option<font>;
        /// Get all registered fonts' keys
        font-keys: func() -> list<font-key>;
        /// Get detailed info of all fonts registered
        fonts-info: func() -> list<font-info>;
        /// Get number of registered fonts
        len: func() -> u32;
        /// Remove a font matching the given key
        remove: func(key: font-key);
        /// Measure a text with some fallback logic
        measure: func(key: font-key, text: string) -> option<text-metrics>;
    }
    str-width-to-number: func(width: string) -> u16;
    number-width-to-str: func(width: u16) -> string;
}

world fontkit {
    export fontkit-interface;
}