extern crate parse_zoneinfo;
use std::collections::BTreeSet;
use std::env;
use std::fs::File;
use std::io::{self, BufRead, BufReader, Write};
use std::path::Path;
use parse_zoneinfo::line::{Line, LineParser};
use parse_zoneinfo::structure::{Child, Structure};
use parse_zoneinfo::table::{Table, TableBuilder};
use parse_zoneinfo::transitions::FixedTimespan;
use parse_zoneinfo::transitions::TableTransitions;
fn strip_comments(mut line: String) -> String {
if let Some(pos) = line.find('#') {
line.truncate(pos);
};
line
}
fn format_rest(rest: Vec<(i64, FixedTimespan)>) -> String {
let mut ret = "&[\n".to_string();
for (start, FixedTimespan { utc_offset, dst_offset, name }) in rest {
ret.push_str(&format!(
" ({start}, FixedTimespan {{ \
utc_offset: {utc}, dst_offset: {dst}, name: \"{name}\" \
}}),\n",
start = start,
utc = utc_offset,
dst = dst_offset,
name = name,
));
}
ret.push_str(" ]");
ret
}
fn convert_bad_chars(name: &str) -> String {
let name = name.replace("/", "__").replace("+", "Plus");
if let Some(pos) = name.find('-') {
if name[pos + 1..].chars().next().map(char::is_numeric).unwrap_or(false) {
name.replace("-", "Minus")
} else {
name.replace("-", "")
}
} else {
name
}
}
fn write_timezone_file(timezone_file: &mut File, table: &Table) -> io::Result<()> {
let zones = table.zonesets.keys().chain(table.links.keys()).collect::<BTreeSet<_>>();
writeln!(timezone_file, "use core::fmt::{{self, Debug, Display, Formatter}};",)?;
writeln!(timezone_file, "use core::str::FromStr;\n",)?;
writeln!(
timezone_file,
"use ::timezone_impl::{{TimeSpans, FixedTimespanSet, FixedTimespan}};\n",
)?;
writeln!(
timezone_file,
"/// TimeZones built at compile time from the tz database
///
/// This implements [`chrono::TimeZone`] so that it may be used in and to
/// construct chrono's DateTime type. See the root module documentation
/// for details."
)?;
writeln!(timezone_file, "#[derive(Clone, Copy, PartialEq, Eq, Hash)]\npub enum Tz {{")?;
for zone in &zones {
let zone_name = convert_bad_chars(zone);
writeln!(
timezone_file,
" /// {raw_zone_name}\n {zone},",
zone = zone_name,
raw_zone_name = zone
)?;
}
writeln!(timezone_file, "}}")?;
writeln!(
timezone_file,
"impl FromStr for Tz {{
#[cfg(feature = \"std\")]
type Err = String;
#[cfg(not(feature = \"std\"))]
type Err = &'static str;
fn from_str(s: &str) -> Result<Self, Self::Err> {{
match s {{"
)?;
for zone in &zones {
let zone_name = convert_bad_chars(zone);
writeln!(
timezone_file,
" \"{raw_zone_name}\" => Ok(Tz::{zone}),",
zone = zone_name,
raw_zone_name = zone
)?;
}
writeln!(
timezone_file,
" #[cfg(feature = \"std\")]
s => Err(format!(\"'{{}}' is not a valid timezone\", s.to_string())),
#[cfg(not(feature = \"std\"))]
_ => Err(\"received invalid timezone\"),
}}
}}
}}\n"
)?;
writeln!(
timezone_file,
"impl Tz {{
pub fn name(self) -> &'static str {{
match self {{"
)?;
for zone in &zones {
let zone_name = convert_bad_chars(zone);
writeln!(
timezone_file,
" Tz::{zone} => \"{raw_zone_name}\",",
zone = zone_name,
raw_zone_name = zone
)?;
}
writeln!(
timezone_file,
" }}
}}
}}\n"
)?;
writeln!(
timezone_file,
"impl Debug for Tz {{
fn fmt(&self, f: &mut Formatter) -> fmt::Result {{
f.write_str(self.name().as_ref())
}}
}}\n"
)?;
writeln!(
timezone_file,
"impl Display for Tz {{
fn fmt(&self, f: &mut Formatter) -> fmt::Result {{
f.write_str(self.name().as_ref())
}}
}}\n"
)?;
writeln!(
timezone_file,
"impl TimeSpans for Tz {{
fn timespans(&self) -> FixedTimespanSet {{
match *self {{"
)?;
for zone in &zones {
let timespans = table.timespans(&zone).unwrap();
let zone_name = convert_bad_chars(zone);
writeln!(
timezone_file,
" Tz::{zone} => {{
const REST: &[(i64, FixedTimespan)] = {rest};
FixedTimespanSet {{
first: FixedTimespan {{
utc_offset: {utc},
dst_offset: {dst},
name: \"{name}\",
}},
rest: REST
}}
}},\n",
zone = zone_name,
rest = format_rest(timespans.rest),
utc = timespans.first.utc_offset,
dst = timespans.first.dst_offset,
name = timespans.first.name,
)?;
}
write!(
timezone_file,
" }}
}}
}}\n"
)?;
write!(
timezone_file,
"/// An array of every known variant
///
/// Useful for iterating over known timezones:
///
/// ```
/// use chrono_tz::{{TZ_VARIANTS, Tz}};
/// assert!(TZ_VARIANTS.iter().any(|v| *v == Tz::UTC));
/// ```
pub static TZ_VARIANTS: [Tz; {num}] = [
",
num = zones.len()
)?;
for zone in &zones {
writeln!(timezone_file, " Tz::{zone},", zone = convert_bad_chars(zone))?;
}
write!(timezone_file, "];")?;
Ok(())
}
fn write_directory_file(directory_file: &mut File, table: &Table) -> io::Result<()> {
writeln!(directory_file, "use timezones::Tz;\n")?;
let zones = table
.zonesets
.keys()
.chain(table.links.keys())
.filter(|zone| !zone.contains('/'))
.collect::<BTreeSet<_>>();
for zone in zones {
let zone = convert_bad_chars(zone);
writeln!(directory_file, "pub const {name} : Tz = Tz::{name};", name = zone)?;
}
writeln!(directory_file)?;
for entry in table.structure() {
if entry.name.contains('/') {
continue;
}
let module_name = convert_bad_chars(entry.name);
writeln!(directory_file, "pub mod {name} {{", name = module_name)?;
writeln!(directory_file, " use timezones::Tz;\n",)?;
for child in entry.children {
match child {
Child::Submodule(name) => {
let submodule_name = convert_bad_chars(name);
writeln!(directory_file, " pub mod {name} {{", name = submodule_name)?;
writeln!(directory_file, " use timezones::Tz;\n",)?;
let full_name = entry.name.to_string() + "/" + name;
for entry in table.structure() {
if entry.name == full_name {
for child in entry.children {
match child {
Child::Submodule(_) => {
panic!("Depth of > 3 nested submodules not implemented!")
}
Child::TimeZone(name) => {
let converted_name = convert_bad_chars(name);
writeln!(directory_file,
" pub const {name} : Tz = Tz::{module_name}__{submodule_name}__{name};",
module_name = module_name,
submodule_name = submodule_name,
name = converted_name,
)?;
}
}
}
}
}
writeln!(directory_file, " }}\n")?;
}
Child::TimeZone(name) => {
let name = convert_bad_chars(name);
writeln!(
directory_file,
" pub const {name} : Tz = Tz::{module_name}__{name};",
module_name = module_name,
name = name
)?;
}
}
}
writeln!(directory_file, "}}\n")?;
}
Ok(())
}
fn main() {
let parser = LineParser::new();
let mut table = TableBuilder::new();
let tzfiles = [
"tz/africa",
"tz/antarctica",
"tz/asia",
"tz/australasia",
"tz/backward",
"tz/etcetera",
"tz/europe",
"tz/northamerica",
"tz/pacificnew",
"tz/southamerica",
];
let lines = tzfiles
.iter()
.map(Path::new)
.map(|p| Path::new(&env::var("CARGO_MANIFEST_DIR").unwrap_or("".to_string())).join(p))
.map(File::open)
.map(Result::unwrap)
.map(BufReader::new)
.flat_map(BufRead::lines)
.map(Result::unwrap)
.map(strip_comments);
for line in lines {
match parser.parse_str(&line).unwrap() {
Line::Zone(zone) => table.add_zone_line(zone).unwrap(),
Line::Continuation(cont) => table.add_continuation_line(cont).unwrap(),
Line::Rule(rule) => table.add_rule_line(rule).unwrap(),
Line::Link(link) => table.add_link_line(link).unwrap(),
Line::Space => {}
}
}
let table = table.build();
let timezone_path = Path::new(&env::var("OUT_DIR").unwrap()).join("timezones.rs");
let mut timezone_file = File::create(&timezone_path).unwrap();
write_timezone_file(&mut timezone_file, &table).unwrap();
let directory_path = Path::new(&env::var("OUT_DIR").unwrap()).join("directory.rs");
let mut directory_file = File::create(&directory_path).unwrap();
write_directory_file(&mut directory_file, &table).unwrap();
}