//! The [name (Naming)](https://docs.microsoft.com/en-us/typography/opentype/spec/name) table

use crate::FontData;

/// 'name'
pub const TAG: Tag = Tag::new(b"name");

include!("../../generated/generated_name.rs");

impl<'a> Name<'a> {
    /// The FontData containing the encoded name strings.
    pub fn string_data(&self) -> FontData<'a> {
        let base = self.offset_data();
        let off = self.storage_offset();
        base.split_off(off as usize).unwrap_or_default()
    }
}

impl NameRecord {
    /// Return a type that can decode the string data for this name entry.
    pub fn string<'a>(&self, data: FontData<'a>) -> Result<NameString<'a>, ReadError> {
        let start = self.string_offset().non_null().unwrap_or(0);
        let end = start + self.length() as usize;

        let data = data
            .as_bytes()
            .get(start..end)
            .ok_or(ReadError::OutOfBounds)?;

        let encoding = Encoding::new(self.platform_id(), self.encoding_id());
        Ok(NameString { data, encoding })
    }
}

impl LangTagRecord {
    /// Return a type that can decode the string data for this name entry.
    pub fn lang_tag<'a>(&self, data: FontData<'a>) -> Result<NameString<'a>, ReadError> {
        let start = self.lang_tag_offset().non_null().unwrap_or(0);
        let end = start + self.length() as usize;

        let data = data
            .as_bytes()
            .get(start..end)
            .ok_or(ReadError::OutOfBounds)?;

        let encoding = Encoding::Utf16Be;
        Ok(NameString { data, encoding })
    }
}

//-- all this is from pinot https://github.com/dfrg/pinot/blob/eff5239018ca50290fb890a84da3dd51505da364/src/name.rs
/// Entry for a name in the naming table.
///
/// This provides an iterator over characters.
#[derive(Copy, Clone, PartialEq, Eq)]
pub struct NameString<'a> {
    data: &'a [u8],
    encoding: Encoding,
}

impl<'a> NameString<'a> {
    /// An iterator over the `char`s in this name.
    pub fn chars(&self) -> CharIter<'a> {
        CharIter {
            data: self.data,
            encoding: self.encoding,
            pos: 0,
        }
    }
}

#[cfg(feature = "traversal")]
impl<'a> traversal::SomeString<'a> for NameString<'a> {
    fn iter_chars(&self) -> Box<dyn Iterator<Item = char> + 'a> {
        Box::new(self.into_iter())
    }
}

#[cfg(feature = "traversal")]
impl NameRecord {
    fn traverse_string<'a>(&self, data: FontData<'a>) -> traversal::FieldType<'a> {
        FieldType::StringOffset(traversal::StringOffset {
            offset: self.string_offset().into(),
            target: self.string(data).map(|s| Box::new(s) as _),
        })
    }
}

#[cfg(feature = "traversal")]
impl LangTagRecord {
    fn traverse_lang_tag<'a>(&self, data: FontData<'a>) -> traversal::FieldType<'a> {
        FieldType::StringOffset(traversal::StringOffset {
            offset: self.lang_tag_offset().into(),
            target: self.lang_tag(data).map(|s| Box::new(s) as _),
        })
    }
}

impl<'a> IntoIterator for NameString<'a> {
    type Item = char;
    type IntoIter = CharIter<'a>;
    fn into_iter(self) -> Self::IntoIter {
        self.chars()
    }
}

impl<'a> std::fmt::Display for NameString<'a> {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        for c in self.chars() {
            c.fmt(f)?;
        }
        Ok(())
    }
}

impl<'a> std::fmt::Debug for NameString<'a> {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        write!(f, "\"{self}\"")
    }
}

/// An iterator over the chars of a name record.
pub struct CharIter<'a> {
    data: &'a [u8],
    encoding: Encoding,
    pos: usize,
}

impl CharIter<'_> {
    fn bump_u16(&mut self) -> Option<u16> {
        let result = self
            .data
            .get(self.pos..self.pos + 2)
            .map(|x| u16::from_be_bytes(x.try_into().unwrap()))?;
        self.pos += 2;
        Some(result)
    }

    fn bump_u8(&mut self) -> Option<u8> {
        let result = self.data.get(self.pos)?;
        self.pos += 1;
        Some(*result)
    }
}

impl<'a> Iterator for CharIter<'a> {
    type Item = char;

    fn next(&mut self) -> Option<Self::Item> {
        if self.pos >= self.data.len() {
            return None;
        }
        let rep = core::char::REPLACEMENT_CHARACTER;
        let raw_c = match self.encoding {
            Encoding::Utf16Be => {
                let c1 = self.bump_u16()? as u32;
                if (0xD800..0xDC00).contains(&c1) {
                    let c2 = self.bump_u16()? as u32;
                    ((c1 & 0x3FF) << 10) + (c2 & 0x3FF) + 0x10000
                } else {
                    c1
                }
            }
            Encoding::MacRoman => {
                let c = self.bump_u8()? as u32;
                if c > 127 {
                    let idx = c as usize - 128;
                    MAC_ROMAN[idx] as u32
                } else {
                    c
                }
            }
            _ => return None,
        };
        Some(std::char::from_u32(raw_c).unwrap_or(rep))
    }
}

/// The encoding used by the name table.
#[derive(Copy, Clone, PartialEq, Eq)]
pub enum Encoding {
    Utf16Be,
    MacRoman,
    Unknown,
}

impl Encoding {
    /// Determine the coding from the platform and encoding id.
    pub fn new(platform_id: u16, encoding_id: u16) -> Encoding {
        match (platform_id, encoding_id) {
            (0, _) => Encoding::Utf16Be,
            (1, 0) => Encoding::MacRoman,
            (3, 0) => Encoding::Utf16Be,
            (3, 1) => Encoding::Utf16Be,
            (3, 10) => Encoding::Utf16Be,
            _ => Encoding::Unknown,
        }
    }
}

#[rustfmt::skip]
const MAC_ROMAN: [u16; 128] = [
    196, 197, 199, 201, 209, 214, 220, 225, 224, 226, 228, 227, 229, 231, 233,
    232, 234, 235, 237, 236, 238, 239, 241, 243, 242, 244, 246, 245, 250, 249,
    251, 252, 8224, 176, 162, 163, 167, 8226, 182, 223, 174, 169, 8482, 180,
    168, 8800, 198, 216, 8734, 177, 8804, 8805, 165, 181, 8706, 8721, 8719,
    960, 8747, 170, 186, 937, 230, 248, 191, 161, 172, 8730, 402, 8776, 8710,
    171, 187, 8230, 160, 192, 195, 213, 338, 339, 8211, 8212, 8220, 8221, 8216,
    8217, 247, 9674, 255, 376, 8260, 8364, 8249, 8250, 64257, 64258, 8225, 183,
    8218, 8222, 8240, 194, 202, 193, 203, 200, 205, 206, 207, 204, 211, 212,
    63743, 210, 218, 219, 217, 305, 710, 732, 175, 728, 729, 730, 184, 733,
    731, 711,
];