//! Implements the basic reader/writer functionality for HFF.
#![warn(missing_docs)]

// Reexport needed types.
#[cfg(feature = "compression")]
pub use hff_core::read::decompress;

// Pull in core if special behavior is needed.
pub use hff_core;

// Pull in common needs.  Aka: prelude.
pub use hff_core::{
    read::{ChunkView, Hff, TableView},
    utilities,
    write::{chunk, hff, table, ChunkDesc, DataSource, HffDesc, TableBuilder},
    ByteOrder, ChunkCache, ContentInfo, Ecc, Error, IdType, Result, Version, BE, LE, NE, OP,
};

// Helper traits which provide blanket implementations over the
// required trait combinations.

mod write_seek;
pub use write_seek::WriteSeek;

mod read_seek;
pub use read_seek::ReadSeek;

/// Create a new builder instance.
pub fn build<'a>(
    tables: impl IntoIterator<Item = hff_core::write::TableBuilder<'a>>,
) -> Result<hff_core::write::HffDesc<'a>> {
    Ok(hff_core::write::hff(tables))
}

mod read;
pub use read::*;

mod write;
pub use write::*;

#[cfg(test)]
mod tests {
    use super::*;

    fn test_table<'a>() -> Result<HffDesc<'a>> {
        Ok(hff([
            table((Ecc::new("Test"), Ecc::new("TestSub")))
            .metadata("This is some metadata attached to the table.")?
            .chunks([
                chunk((Ecc::new("TRC0"), Ecc::new("TRS0")), "Chunks can be most types.  This is passed as an arbitrary byte array.".as_bytes())?,
                chunk(
                    (Ecc::new("TRC1"),
                    Ecc::new("TRS1")),
                    "Chunks provided to the table will maintain their order.",
                )?,
                chunk(
                    (Ecc::new("TRC2"),
                    Ecc::new("TRS2")),
                    "So, iterating through the chunks has the same order as presented here.",
                )?,
                chunk(
                    (Ecc::new("TRC3"),
                    Ecc::new("TRS3")),
                    "Chunks can be supplied with data from multiple sources.",
                )?,
                chunk(
                    (Ecc::new("TRC4"),
                    Ecc::new("TRS4")),
                    "In fact, providing a std::path::Path will pull the content of a file in as the chunk data.",
                )?,
                // Compress the string if compression is enabled.
                #[cfg(feature = "compression")]
                chunk(
                    (Ecc::new("TRC5"),
                    Ecc::new("TRS5")),
                    // Compressing chunks is just sending in a tuple with the compression level.
                    // Using lzma for compression and the level is expected to be between 0 and 9.
                    (9, "In the case of a lazy_write, the file will be opened and streamed directly to the writer without being buffered in memory."),
                )?,
                // Don't compress the string if compression is disabled.
                #[cfg(not(feature = "compression"))]
                chunk(
                    (Ecc::new("TRC5"),
                    Ecc::new("TRS5")),
                    "In the case of a lazy_write, the file will be opened and streamed directly to the writer without being buffered in memory.",
                )?,
            ])
            .children([
                table((Ecc::new("C0Prime"), Ecc::new("C0Sub")))
                .metadata("Each table has its own metadata.")?
                .chunks([chunk((Ecc::new("C0C0"), Ecc::new("C0S0")), "Each table also has its own set of chunks.")?])
                .children([
                    table((Ecc::new("C1Prime"), Ecc::new("C1Sub")))
                    .chunks([
                        chunk(
                            (Ecc::new("C1C0"),
                            Ecc::new("C1S0")),
                            "They will only be listed while iterating that specific table.",
                        )?
                    ]),
                    table((Ecc::new("C2Prime"), Ecc::new("C2Sub")))
                    .children([
                        table((Ecc::new("C3Prime"), Ecc::new("C3Sub")))
                        .chunks([
                            chunk((Ecc::new("C2C0"), Ecc::new("C2S0")), "Tables don't *have* to have chunks, tables can be used to simply contain other tables.")?
                        ])
                    ])
                ]),
                table((Ecc::new("C4Prime"), Ecc::new("C4Sub"))).chunks([
                    chunk((Ecc::new("C4C0"), Ecc::new("C4S0")),"The last chunk in the overall file.")?
                ])
                .metadata("And we're done.")?
            ])
        ]))
    }

    fn checks(hff: &Hff<ChunkCache>) {
        {
            // Check the content of root is as expected.
            let root = hff.tables().next().unwrap();
            assert_eq!(
                root.identifier(),
                (Ecc::new("Test"), Ecc::new("TestSub")).into()
            );
            assert_eq!(root.child_count(), 2);
            assert_eq!(root.chunk_count(), 6);

            // Check that we get a proper child iterator from the root.
            let mut root_children = root.iter();
            let c0 = root_children.next().unwrap();
            assert_eq!(c0.identifier().as_ecc2().0, "C0Prime".into());
            let c4 = root_children.next().unwrap();
            assert_eq!(c4.identifier().as_ecc2().0, "C4Prime".into());
            assert!(root_children.next().is_none());
        }

        {
            // Check the metadata for the root.
            let root = hff.tables().next().unwrap();
            // The resulting reader is just a reference to the data
            // in the content.  You can take a &mut Read on it if you
            // wish to use it with std::io methods such as copy.
            let metadata = hff.read(&root).unwrap();
            assert!(std::str::from_utf8(metadata)
                .unwrap()
                .starts_with("This is some metadata"));

            // Check the last table (second root child) metadata.
            let mut children = hff.tables().next().unwrap().iter();
            children.next();
            let c4 = children.next().unwrap();
            let metadata = hff.read(&c4).unwrap();
            assert!(std::str::from_utf8(metadata)
                .unwrap()
                .starts_with("And we're done."));
        }

        {
            // Check the root chunks are as expected.
            let root = hff.tables().next().unwrap();

            let test_data = [
                ("TRC0", "TRS0", "Chunks can be most types.  This is passed as an arbitrary byte array."),
                (
                    "TRC1",
                    "TRS1",
                    "Chunks provided to the table will maintain their order.",
                ),
                (
                    "TRC2",
                    "TRS2",
                    "So, iterating through the chunks has the same order as presented here.",
                ),
                (
                    "TRC3",
                    "TRS3",
                    "Chunks can be supplied with data from multiple sources.",
                ),
                (
                    "TRC4",
                    "TRS4",
                    "In fact, providing a std::path::Path will pull the content of a file in as the chunk data.",
                ),
                (
                    "TRC5",
                    "TRS5",
                    "In the case of a lazy_write, the file will be opened and streamed directly to the writer without being buffered in memory.",
                )
            ];
            for (index, chunk) in root.chunks().enumerate() {
                let test_entry = test_data[index];
                let (primary, secondary): (Ecc, Ecc) = chunk.identifier().into();
                assert_eq!(Ecc::new(test_entry.0), primary);
                assert_eq!(Ecc::new(test_entry.1), secondary);

                #[cfg(feature = "compression")]
                let (_, secondary): (Ecc, Ecc) = chunk.identifier().into();
                if secondary == Ecc::new("TRS5") {
                    let decompressed = decompress(hff.read(&chunk).unwrap()).unwrap();
                    assert_eq!(decompressed.len(), test_entry.2.len());
                    assert_eq!(decompressed, Vec::from(test_entry.2.as_bytes()));
                } else {
                    assert_eq!(chunk.size(), test_entry.2.len());
                    assert_eq!(
                        hff.read(&chunk).unwrap(),
                        Vec::from(test_entry.2.as_bytes())
                    );
                }
                #[cfg(not(feature = "compression"))]
                {
                    assert_eq!(chunk.size(), test_entry.2.len());
                    assert_eq!(
                        hff.read(&chunk).unwrap(),
                        Vec::from(test_entry.2.as_bytes())
                    );
                }
            }

            {
                let test_data = [
                    (0, "Test", "TestSub"),
                    (1, "C0Prime", "C0Sub"),
                    (2, "C1Prime", "C1Sub"),
                    (2, "C2Prime", "C2Sub"),
                    (3, "C3Prime", "C3Sub"),
                    (1, "C4Prime", "C4Sub"),
                ];
                // Test depth first iteration.
                for ((depth, table), data) in hff.depth_first().zip(test_data.iter()) {
                    assert_eq!(depth, data.0);
                    assert_eq!(
                        table.identifier(),
                        (Ecc::new(data.1), Ecc::new(data.2)).into()
                    );
                }
            }
        }
    }

    #[test]
    fn test() {
        use std::io::Seek;

        // Simple dev test for structure.
        {
            let content = test_table().unwrap();
            let buffer = vec![];
            let mut writer = std::io::Cursor::new(buffer);
            assert!(content
                .lazy_write::<hff_core::NE>(IdType::Ecc2, "Test", &mut writer)
                .is_ok());

            // Read it back in and iterate.
            writer.rewind().unwrap();
            let access = crate::read::read(&mut writer).unwrap();
            checks(&access);
        }

        // Simple dev test for structure.
        {
            let content = test_table().unwrap();
            let mut buffer = vec![];

            assert!(content
                .write::<hff_core::OP>(IdType::Ecc2, "Test", &mut buffer)
                .is_ok());

            // Read it back in and iterate.
            let access = crate::read::read(&mut buffer.as_slice()).unwrap();
            checks(&access);
        }
    }
}