datui-lib 0.4.0

//! ArduPilot DataFlash logs (`.bin`).
//!
//! A DataFlash log describes its own messages: each `FMT` record gives a message
//! type's id, length, name, format characters and field labels; every other record is
//! `A3 95`, its type's id, and its fields packed end to end. One pass records where
//! each type's records start ([`crate::indexed`]) and reads the units and multipliers
//! of `FMTU`, `UNIT` and `MULT` when the log has them; each type is then a table
//! decoded from a map of the file, its columns typed by their format characters.
//!
//! Every length is bounded: a record by its type's length and the file's end. A byte
//! that does not start a record is passed over to the next `A3 95` and counted.

use std::collections::{BTreeMap, HashMap};
use std::path::Path;
use std::sync::Arc;

use color_eyre::Result;
use color_eyre::eyre::eyre;

use crate::error_display::{FileError, in_file};
use polars::prelude::*;

use crate::fixed_records::{Bytes, ColumnLayout, Logical, Physical};
use crate::indexed::{IndexedRecords, Offsets};
use crate::model_files::MetaValue;
use crate::sqlite::Table;
use crate::text_formats::Detail;

/// What datui does with a DataFlash log: see [`crate::readers`].
pub(crate) const READER: crate::readers::Reader = crate::readers::Reader {
    scan,
    signatures: &[crate::readers::Signature {
        says: |head, _| looks_like(head),
        kind: crate::readers::Kind::Magic,
        trusted: crate::readers::Trusted {
            tables: true,
            ..crate::readers::EVERYWHERE
        },
    }],
    tables: Some(listed),
    ..crate::readers::BASE
};

const HEAD: [u8; 2] = [0xA3, 0x95];
/// The type id of `FMT`, the record that defines the others.
const FMT: u8 = 0x80;
/// An `FMT` record's length: header, type, length, name, format, labels.
const FMT_LEN: usize = 89;

/// Whether `head`, the first bytes of a file, begins a DataFlash log: an `FMT` record
/// that defines `FMT` itself.
pub fn looks_like(head: &[u8]) -> bool {
    head.len() >= 8
        && head[..3] == [0xA3, 0x95, FMT]
        && head[3] == FMT
        && head[4] as usize == FMT_LEN
        && &head[5..8] == b"FMT"
}

/// A format character's storage, width, values, and the scale its value carries.
fn format_char(c: u8) -> Option<(Physical, usize, usize, Option<f64>)> {
    Some(match c {
        b'b' => (Physical::Signed(1), 1, 1, None),
        b'B' | b'M' => (Physical::Unsigned(1), 1, 1, None),
        b'h' => (Physical::Signed(2), 2, 1, None),
        b'H' => (Physical::Unsigned(2), 2, 1, None),
        b'i' => (Physical::Signed(4), 4, 1, None),
        b'I' => (Physical::Unsigned(4), 4, 1, None),
        b'q' => (Physical::Signed(8), 8, 1, None),
        b'Q' => (Physical::Unsigned(8), 8, 1, None),
        b'f' => (Physical::Float(4), 4, 1, None),
        b'd' => (Physical::Float(8), 8, 1, None),
        b'g' => (Physical::Float(2), 2, 1, None),
        b'n' => (Physical::Text, 4, 1, None),
        b'N' => (Physical::Text, 16, 1, None),
        b'Z' => (Physical::Text, 64, 1, None),
        b'c' => (Physical::Signed(2), 2, 1, Some(0.01)),
        b'C' => (Physical::Unsigned(2), 2, 1, Some(0.01)),
        b'e' => (Physical::Signed(4), 4, 1, Some(0.01)),
        b'E' => (Physical::Unsigned(4), 4, 1, Some(0.01)),
        // Latitude and longitude in 1e-7 degrees.
        b'L' => (Physical::Signed(4), 4, 1, Some(1e-7)),
        b'a' => (Physical::Signed(2), 2, 32, None),
        _ => return None,
    })
}

/// One message type, as its `FMT` record defines it.
#[derive(Debug)]
pub struct MessageType {
    pub id: u8,
    pub name: String,
    /// The whole record's length, header included.
    pub length: usize,
    pub format: String,
    pub labels: Vec<String>,
    pub offsets: Arc<Offsets>,
    /// Unit and multiplier ids per field, from `FMTU`.
    pub unit_ids: Option<String>,
    pub mult_ids: Option<String>,
}

/// What one pass over a DataFlash log found.
#[derive(Debug, Default)]
pub struct Index {
    pub types: BTreeMap<u8, MessageType>,
    pub units: HashMap<u8, String>,
    pub mults: HashMap<u8, f64>,
    pub skipped: usize,
    pub damaged: usize,
    pub past_limit: usize,
    /// `FMT` records whose format does not add up to their length, or has a character
    /// datui does not know.
    pub bad_formats: Vec<String>,
    pub cut_short: bool,
}

impl Index {
    /// The tables with records, by name.
    pub fn names(&self) -> Vec<(String, u8)> {
        let mut names: Vec<(String, u8)> = self
            .types
            .values()
            .filter(|t| !t.offsets.is_empty() && t.id != FMT)
            .map(|t| (t.name.clone(), t.id))
            .collect();
        names.sort();
        // Two types of one name (a log that redefines one) keep their ids apart.
        let mut seen: HashMap<String, usize> = HashMap::new();
        for (name, _) in &names {
            *seen.entry(name.clone()).or_default() += 1;
        }
        for (name, id) in &mut names {
            if seen[name.as_str()] > 1 {
                *name = format!("{name}.{id}");
            }
        }
        names
    }
}

/// Text from a fixed-width field.
fn text(bytes: &[u8]) -> String {
    crate::fixed_records::text(bytes)
}

/// The size a format's characters add up to, `None` for one datui does not know.
fn format_size(format: &str) -> Option<usize> {
    format.bytes().try_fold(0usize, |n, c| {
        let (_, width, count, _) = format_char(c)?;
        n.checked_add(width * count)
    })
}

/// The fields of a record of `t` read as plain values, for `FMTU`, `UNIT` and `MULT`.
fn fields<'a>(t: &MessageType, record: &'a [u8]) -> Vec<(&'a [u8], u8)> {
    let mut at = 3;
    let mut out = Vec::new();
    for c in t.format.bytes() {
        let Some((_, width, count, _)) = format_char(c) else {
            break;
        };
        let len = width * count;
        let Some(bytes) = record.get(at..at + len) else {
            break;
        };
        out.push((bytes, c));
        at += len;
    }
    out
}

/// Index the DataFlash log in `data`: one pass, start to end.
pub fn index(data: &[u8]) -> std::result::Result<Index, String> {
    if !looks_like(data) {
        return Err("not a DataFlash log: it does not start with an FMT record".into());
    }
    let mut index = Index::default();
    let mut records = 0usize;
    let mut fmtu: Vec<(u8, String, String)> = Vec::new();
    let mut building: HashMap<u8, Offsets> = HashMap::new();
    let mut at = 0usize;
    while at < data.len() {
        if data.get(at..at + 2) != Some(&HEAD[..]) {
            // Not a record: the next header, if there is one.
            match memchr::memmem::find(&data[at + 1..], &HEAD) {
                Some(i) => {
                    index.skipped += i + 1;
                    index.damaged += 1;
                    at += i + 1;
                    continue;
                }
                None => {
                    index.skipped += data.len() - at;
                    index.damaged += 1;
                    break;
                }
            }
        }
        let Some(&id) = data.get(at + 2) else {
            index.cut_short = true;
            break;
        };
        if id == FMT {
            let Some(record) = data.get(at..at + FMT_LEN) else {
                index.cut_short = true;
                break;
            };
            let defined = record[3];
            let length = record[4] as usize;
            let name = text(&record[5..9]);
            let format = text(&record[9..25]);
            let labels: Vec<String> = text(&record[25..89])
                .split(',')
                .map(str::to_string)
                .collect();
            match format_size(&format) {
                Some(size) if size + 3 == length && length >= 3 => {
                    // A type redefined alike keeps the records it had; one redefined
                    // otherwise starts again, as its records are read differently.
                    let same = index
                        .types
                        .get(&defined)
                        .is_some_and(|t| t.length == length && t.format == format);
                    if !same {
                        building.insert(defined, Offsets::for_file(data.len()));
                    }
                    index.types.insert(
                        defined,
                        MessageType {
                            id: defined,
                            name,
                            length,
                            format,
                            labels,
                            offsets: Arc::new(Offsets::Narrow(Vec::new())),
                            unit_ids: None,
                            mult_ids: None,
                        },
                    );
                }
                _ => {
                    if index.bad_formats.len() < 1000 {
                        index.bad_formats.push(format!("{name} ({format})"));
                    }
                }
            }
            at += FMT_LEN;
            continue;
        }
        let Some(t) = index.types.get_mut(&id) else {
            // A type no FMT defined: its length is unknown, so look for the next header.
            match memchr::memmem::find(&data[at + 2..], &HEAD) {
                Some(i) => {
                    index.skipped += i + 2;
                    index.damaged += 1;
                    at += i + 2;
                    continue;
                }
                None => {
                    index.skipped += data.len() - at;
                    index.damaged += 1;
                    break;
                }
            }
        };
        let Some(record) = data.get(at..at + t.length) else {
            index.cut_short = true;
            break;
        };
        match t.name.as_str() {
            "FMTU" => {
                let f = fields(t, record);
                if let [_, (ty, _), (units, _), (mults, _), ..] = f.as_slice()
                    && let Some(&ty) = ty.first()
                    && fmtu.len() < 1000
                {
                    fmtu.push((ty, text(units), text(mults)));
                }
            }
            "UNIT" => {
                let f = fields(t, record);
                if let [_, (unit_id, _), (label, _), ..] = f.as_slice()
                    && let Some(&unit_id) = unit_id.first()
                {
                    index.units.insert(unit_id, text(label));
                }
            }
            "MULT" => {
                let f = fields(t, record);
                if let [_, (mult_id, _), (mult, b'd'), ..] = f.as_slice()
                    && let Some(&mult_id) = mult_id.first()
                    && let Ok(raw) = <[u8; 8]>::try_from(*mult)
                {
                    index.mults.insert(mult_id, f64::from_le_bytes(raw));
                }
            }
            _ => {}
        }
        if records < crate::indexed::MAX_RECORDS {
            building
                .entry(id)
                .or_insert_with(|| Offsets::for_file(data.len()))
                .push(at);
            records += 1;
        } else {
            index.past_limit += 1;
        }
        at += t.length;
    }
    for (ty, units, mults) in fmtu {
        if let Some(t) = index.types.get_mut(&ty) {
            t.unit_ids = Some(units);
            t.mult_ids = Some(mults);
        }
    }
    for (id, mut offsets) in building {
        if let Some(t) = index.types.get_mut(&id) {
            offsets.shrink();
            t.offsets = Arc::new(offsets);
        }
    }
    Ok(index)
}

/// The columns of a message type, and each one's unit.
pub fn columns(index: &Index, t: &MessageType) -> (Vec<ColumnLayout>, Vec<(String, String)>) {
    let mut columns = Vec::new();
    let mut units = Vec::new();
    let mut at = 3;
    for (i, c) in t.format.bytes().enumerate() {
        let Some((physical, width, count, scale)) = format_char(c) else {
            break;
        };
        let mut name = t
            .labels
            .get(i)
            .filter(|l| !l.is_empty())
            .cloned()
            .unwrap_or_else(|| format!("field{i}"));
        // A label a log repeats keeps both columns, the later by its place.
        if columns
            .iter()
            .any(|c: &ColumnLayout| c.name == name.as_str())
        {
            name = format!("{name}_{i}");
        }
        let mut column = match physical {
            Physical::Text => ColumnLayout::new(&name, at, 0, physical, width),
            _ => {
                let mut c = ColumnLayout::new(&name, at, 0, physical, width);
                c.count = count;
                c
            }
        };
        let mult = t
            .mult_ids
            .as_ref()
            .and_then(|m| m.as_bytes().get(i))
            .and_then(|id| index.mults.get(id))
            .copied();
        if (name == "TimeUS" && c == b'Q') || (name == "TimeMS" && c == b'I') {
            column.logical = Logical::Duration {
                unit: if c == b'Q' {
                    TimeUnit::Microseconds
                } else {
                    TimeUnit::Milliseconds
                },
                multiplier: 1,
            };
        } else if let Some(scale) = scale {
            column.logical = Logical::Linear {
                factor: scale,
                offset: 0.0,
            };
        } else if physical.is_integer()
            && count == 1
            && let Some(mult) = mult.filter(|m| *m != 1.0 && *m != 0.0 && m.is_finite())
        {
            // An integer the log scales: FMTU says by what.
            column.logical = Logical::Linear {
                factor: mult,
                offset: 0.0,
            };
        }
        if let Some(unit) = t
            .unit_ids
            .as_ref()
            .and_then(|u| u.as_bytes().get(i))
            .and_then(|id| index.units.get(id))
            .filter(|u| !u.is_empty())
        {
            units.push((name.clone(), unit.clone()));
        }
        columns.push(column);
        at += width * count;
    }
    (columns, units)
}

/// The log's tables as its indexing pass found them: listed once it has been opened,
/// and not read here, where the home screen waits.
pub fn listed(file: &Path) -> Result<Vec<Table>> {
    crate::indexed::peek::<Index>(file)
        .map(|index| tables(&index))
        .ok_or_else(|| eyre!("Open the log to list its tables."))
}

/// The tables of an indexed log, for the home screen and `--table`.
pub fn tables(index: &Index) -> Vec<Table> {
    index
        .names()
        .into_iter()
        .map(|(name, id)| Table {
            name,
            kind: "message".to_string(),
            internal: false,
            columns: columns(index, &index.types[&id])
                .0
                .iter()
                .map(|c| (c.name.to_string(), String::new()))
                .collect(),
        })
        .collect()
}

/// What the Info panel's DataFlash tab says.
pub fn detail(index: &Index) -> Detail {
    let names = index.names();
    let records: usize = names
        .iter()
        .map(|(_, id)| index.types[id].offsets.len())
        .sum();
    let lines = vec![
        format!(
            "Message types: {} with records, {} defined",
            names.len(),
            index.types.len()
        ),
        format!("Records: {}", crate::numfmt::group_chrome(records)),
        format!(
            "Units: {}",
            if index.units.is_empty() {
                "none in the log".to_string()
            } else {
                format!("{} (FMTU, UNIT, MULT)", index.units.len())
            }
        ),
    ];
    let list = names.iter().map(|(name, id)| {
        let t = &index.types[id];
        (
            name.clone(),
            MetaValue::Text(format!(
                "{} records, format {}, {} bytes",
                crate::numfmt::group_chrome(t.offsets.len()),
                t.format,
                t.length
            )),
        )
    });
    Detail {
        tab: crate::text_formats::tab(crate::FileFormat::Dataflash),
        lines,
        list_title: "Messages",
        list: crate::text_formats::capped_list(list, names.len()),
        first: false,
        ..Default::default()
    }
}

/// What the Notes tab says of the pass.
pub fn notes(index: &Index) -> Vec<String> {
    let group = |n: usize| crate::numfmt::group_chrome(n);
    let mut notes = Vec::new();
    if index.damaged > 0 {
        notes.push(format!(
            "{} damaged stretches skipped ({} bytes)",
            group(index.damaged),
            group(index.skipped)
        ));
    }
    if index.cut_short {
        notes.push("log cut short mid-record".to_string());
    }
    if index.past_limit > 0 {
        notes.push(format!(
            "{} records left out: past the first {}",
            group(index.past_limit),
            group(crate::indexed::MAX_RECORDS)
        ));
    }
    if !index.bad_formats.is_empty() {
        notes.push(format!(
            "{} message types not read, format unreadable: {}",
            index.bad_formats.len(),
            index
                .bad_formats
                .iter()
                .take(10)
                .cloned()
                .collect::<Vec<_>>()
                .join(", ")
        ));
    }
    notes
}

/// The index of the DataFlash log at `path`, made by one pass or kept from one.
pub fn indexed(path: &Path) -> Result<(Arc<Bytes>, Arc<Index>)> {
    let bytes = Arc::new(Bytes::map(path).map_err(|e| in_file(path, e.into()))?);
    let index = crate::indexed::cached(path, || index(bytes.as_slice()))
        .map_err(|e| FileError::new(path, e))?;
    Ok((bytes, index))
}

/// What opening a DataFlash log finds.
pub enum Open {
    Table {
        lf: Box<LazyFrame>,
        opened: Box<crate::members::Opened>,
    },
    Several(Vec<String>),
}

/// Open the DataFlash log at `path`: the table `wanted` names, its one table, or the
/// list.
pub fn open(path: &Path, wanted: Option<&str>) -> Result<Open> {
    let (bytes, index) = indexed(path)?;
    let tables = tables(&index);
    let picked = match crate::members::pick(
        tables.clone(),
        wanted,
        path,
        " The log has no records but its formats.",
    )? {
        crate::sqlite::Pick::One(table) => table.name,
        crate::sqlite::Pick::Several(tables) => {
            return Ok(Open::Several(tables.into_iter().map(|t| t.name).collect()));
        }
    };
    let id = index
        .names()
        .into_iter()
        .find(|(n, _)| *n == picked)
        .map(|(_, id)| id)
        .expect("picked from the names");
    let t = &index.types[&id];
    let (columns, units) = columns(&index, t);
    let records = Arc::new(
        IndexedRecords::new(bytes, t.offsets.clone(), columns)
            .map_err(|e| FileError::new(path, format!("table \"{picked}\": {e}")))?,
    );
    let opened = crate::members::Opened {
        window: Some((records.clone(), records.rows())),
        detail: Some(Arc::new(detail(&index))),
        other_tables: crate::members::others(&tables, &picked),
        notes: notes(&index)
            .into_iter()
            .map(|n| crate::text_formats::note(n, "the log".to_string()))
            .collect(),
        units,
        indexing: None,
        numbering: None,
    };
    Ok(Open::Table {
        lf: Box::new(records.lazy()),
        opened: Box::new(opened),
    })
}

/// The scan of a DataFlash log: the table `--table` names, or its only one, decoded from
/// the file where it is shown; or none yet when it has several. The pass that indexes
/// the log is kept, so a table chosen from the list reads nothing again.
fn scan(input: crate::readers::ScanIn<'_>) -> Result<crate::scan::Scan> {
    let file = input.path();
    Ok(match open(file, input.options.table.as_deref())? {
        Open::Table { lf, opened } => {
            input.report.opened = Some(Arc::new(*opened));
            (*lf).into()
        }
        Open::Several(tables) => crate::scan::Scan::Tables {
            file: file.to_path_buf(),
            tables,
            format: input.format,
        },
    })
}

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

    /// A file that is not a DataFlash log names itself, in the one shape.
    #[test]
    fn errors_name_the_file() {
        crate::readers::bad_input::each_names_its_file(
            crate::FileFormat::Dataflash,
            &[(
                "text.bin",
                b"hello there, this is text",
                "Not a DataFlash log",
            )],
        );
    }

    fn fmt(id: u8, name: &str, format: &str, labels: &str) -> Vec<u8> {
        let length = if id == FMT {
            FMT_LEN
        } else {
            format_size(format).unwrap() + 3
        };
        let mut r = vec![0xA3, 0x95, FMT, id, length as u8];
        let pad = |s: &str, n: usize| {
            let mut b = s.as_bytes().to_vec();
            b.resize(n, 0);
            b
        };
        r.extend(pad(name, 4));
        r.extend(pad(format, 16));
        r.extend(pad(labels, 64));
        r
    }

    /// A small log: FMT, the unit tables, two message types interleaved, a scaled
    /// field, units, damage, and a record cut off at the end.
    pub(crate) fn tiny() -> Vec<u8> {
        let mut log = fmt(FMT, "FMT", "BBnNZ", "Type,Length,Name,Format,Columns");
        log.extend(fmt(129, "UNIT", "QbZ", "TimeUS,Id,Label"));
        log.extend(fmt(130, "MULT", "Qbd", "TimeUS,Id,Mult"));
        log.extend(fmt(131, "FMTU", "QBNN", "TimeUS,FmtType,UnitIds,MultIds"));
        log.extend(fmt(140, "ATT", "QccH", "TimeUS,Roll,Pitch,Yaw"));
        log.extend(fmt(141, "BARO", "QfiL", "TimeUS,Alt,Press,Lat"));
        let unit = |id: u8, label: &str| {
            let mut r = vec![0xA3, 0x95, 129];
            r.extend(0u64.to_le_bytes());
            r.push(id);
            let mut l = label.as_bytes().to_vec();
            l.resize(64, 0);
            r.extend(l);
            r
        };
        log.extend(unit(b'd', "deg"));
        log.extend(unit(b'm', "m"));
        log.extend(unit(b'P', "Pa"));
        let mut mult = vec![0xA3, 0x95, 130];
        mult.extend(0u64.to_le_bytes());
        mult.push(b'2');
        mult.extend(100.0f64.to_le_bytes());
        log.extend(mult);
        let fmtu = |ty: u8, units: &str, mults: &str| {
            let mut r = vec![0xA3, 0x95, 131];
            r.extend(0u64.to_le_bytes());
            r.push(ty);
            for s in [units, mults] {
                let mut b = s.as_bytes().to_vec();
                b.resize(16, 0);
                r.extend(b);
            }
            r
        };
        log.extend(fmtu(141, "-mPd", "-02?"));
        for i in 0..3u64 {
            let mut att = vec![0xA3, 0x95, 140];
            att.extend((1000 + i * 10).to_le_bytes());
            att.extend((150i16 + i as i16).to_le_bytes());
            att.extend((-250i16).to_le_bytes());
            att.extend(9000u16.to_le_bytes());
            log.extend(att);
            let mut baro = vec![0xA3, 0x95, 141];
            baro.extend((1005 + i * 10).to_le_bytes());
            baro.extend((12.5f32 + i as f32).to_le_bytes());
            baro.extend(101_325i32.to_le_bytes());
            baro.extend(473_977_418i32.to_le_bytes());
            log.extend(baro);
            if i == 1 {
                log.extend([0x00, 0xA3, 0x11]);
            }
        }
        log.extend([0xA3, 0x95, 140, 1, 2]);
        log
    }

    #[test]
    fn types_records_units_and_damage() {
        let data = tiny();
        assert!(looks_like(&data));
        let index = index(&data).unwrap();
        let names: Vec<String> = index.names().into_iter().map(|(n, _)| n).collect();
        assert_eq!(names, ["ATT", "BARO", "FMTU", "MULT", "UNIT"]);
        assert_eq!(index.types[&140].offsets.len(), 3);
        assert_eq!(index.damaged, 1);
        assert!(index.cut_short);
        let (columns, units) = columns(&index, &index.types[&141]);
        assert_eq!(
            units,
            [
                ("Alt".to_string(), "m".to_string()),
                ("Press".to_string(), "Pa".to_string()),
                ("Lat".to_string(), "deg".to_string())
            ]
        );
        let records = Arc::new(
            IndexedRecords::new(
                Arc::new(Bytes::Owned(data)),
                index.types[&141].offsets.clone(),
                columns,
            )
            .unwrap(),
        );
        let df = records.lazy().collect().unwrap();
        assert_eq!(
            df.column("TimeUS").unwrap().dtype(),
            &DataType::Duration(TimeUnit::Microseconds)
        );
        // The format scales latitude; FMTU's multiplier scales the pressure.
        let lat = df.column("Lat").unwrap().f64().unwrap().get(0).unwrap();
        assert!((lat - 47.3977418).abs() < 1e-9);
        assert_eq!(
            df.column("Press").unwrap().f64().unwrap().get(0),
            Some(10_132_500.0)
        );
    }

    #[test]
    fn scaled_characters() {
        let data = tiny();
        let index = index(&data).unwrap();
        let (columns, _) = columns(&index, &index.types[&140]);
        let records = Arc::new(
            IndexedRecords::new(
                Arc::new(Bytes::Owned(data)),
                index.types[&140].offsets.clone(),
                columns,
            )
            .unwrap(),
        );
        let df = records.lazy().collect().unwrap();
        assert_eq!(
            df.column("Roll").unwrap().f64().unwrap().to_vec(),
            [Some(1.5), Some(1.51), Some(1.52)]
        );
        assert_eq!(df.column("Yaw").unwrap().u16().unwrap().get(0), Some(9000));
    }

    #[test]
    fn garbage_is_bounded() {
        assert!(index(b"nope").is_err());
        let mut data = fmt(FMT, "FMT", "BBnNZ", "Type,Length,Name,Format,Columns");
        data.extend([0xA3, 0x95, 0x80, 7, 200]);
        data.extend([0xA3; 50]);
        let index = index(&data).unwrap();
        assert!(index.names().is_empty());
    }
}