sq3-rs 0.2.5

use std::fmt::Display;

use sq3_derive::Name;

use crate::{
    field_parsing_error,
    result::SqliteResult,
    traits::{ParseBytes, TypeName},
};

/// # File format version numbers (2 Bytes)
///
///  The file format write version and file format read version at offsets 18
/// and 19 are intended to allow for enhancements of the file format in future
/// versions of Sqlite. In current versions of Sqlite, both of these values
/// are:
///   - `1` for rollback journalling modes; and
///   - `2` for WAL journalling mode.
///
///  If a version of Sqlite coded to the current file format specification
/// encounters a database file where the read version is 1 or 2 but the write
/// version is greater than 2, then the database file must be treated as
/// read-only. If a database file with a read version greater than 2 is
/// encountered, then that database cannot be read or written.
#[derive(Debug, Default, Name)]
pub struct FileFormatVersionNumbers {
    /// File format write version. 1 for legacy; 2 for WAL.
    write_version: FileFormatWriteVersion,
    /// File format read version. 1 for legacy; 2 for WAL.
    read_version: FileFormatReadVersion,
}

impl FileFormatVersionNumbers {
    pub fn write_version(&self) -> &FileFormatWriteVersion {
        &self.write_version
    }

    pub fn read_version(&self) -> &FileFormatReadVersion {
        &self.read_version
    }
}

impl ParseBytes for FileFormatVersionNumbers {
    const LENGTH_BYTES: usize = 2;

    fn parsing_handler(bytes: &[u8]) -> SqliteResult<Self> {
        let write_version = FileFormatWriteVersion::parsing_handler(&[bytes[0]])?;
        let read_version = FileFormatReadVersion::parsing_handler(&[bytes[1]])?;
        Ok(Self {
            write_version,
            read_version,
        })
    }
}

#[derive(Debug, Default, Name)]
pub enum FileFormatWriteVersion {
    #[default]
    Legacy,
    /// Write-Ahead Log
    ///
    /// Reference: https://www.sqlite.org/wal.html
    WAL,
}

impl From<&FileFormatWriteVersion> for u8 {
    fn from(value: &FileFormatWriteVersion) -> Self {
        match value {
            FileFormatWriteVersion::Legacy => 1,
            FileFormatWriteVersion::WAL => 2,
        }
    }
}

impl ParseBytes for FileFormatWriteVersion {
    const LENGTH_BYTES: usize = 1;

    fn parsing_handler(bytes: &[u8]) -> SqliteResult<Self> {
        let one_byte = *bytes
            .first()
            .ok_or(field_parsing_error! {Self::NAME.into()})?;
        match one_byte {
            1 => Ok(Self::Legacy),
            2 => Ok(Self::WAL),
            _ => Err(field_parsing_error! {Self::NAME.into()}),
        }
    }
}

impl Display for FileFormatWriteVersion {
    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
        write!(f, "{}", u8::from(self))
    }
}

#[derive(Debug, Default, Name)]
pub enum FileFormatReadVersion {
    #[default]
    Legacy,
    /// Write-Ahead Log
    ///
    /// Reference: https://www.sqlite.org/wal.html
    WAL,
}

impl From<&FileFormatReadVersion> for u8 {
    fn from(value: &FileFormatReadVersion) -> Self {
        match value {
            FileFormatReadVersion::Legacy => 1,
            FileFormatReadVersion::WAL => 2,
        }
    }
}

impl ParseBytes for FileFormatReadVersion {
    const LENGTH_BYTES: usize = 1;

    fn parsing_handler(bytes: &[u8]) -> SqliteResult<Self> {
        let one_byte = *bytes
            .first()
            .ok_or(field_parsing_error! {Self::NAME.into()})?;
        match one_byte {
            1 => Ok(Self::Legacy),
            2 => Ok(Self::WAL),
            _ => Err(field_parsing_error! {Self::NAME.into()}),
        }
    }
}

impl Display for FileFormatReadVersion {
    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
        write!(f, "{}", u8::from(self))
    }
}