#!/usr/bin/env python3
#
# Copyright 2011-2015 The Rust Project Developers. See the COPYRIGHT
# file at the top-level directory of this distribution and at
# http://rust-lang.org/COPYRIGHT.
#
# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
# option. This file may not be copied, modified, or distributed
# except according to those terms.

# This script uses the following Unicode security tables:
# - IdentifierStatus.txt
# - ReadMe.txt
#
# Since this should not require frequent updates, we just store this
# out-of-line and check the unicode.rs file into git.

import fileinput, re, os, sys, operator

preamble = '''// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

// NOTE: The following code was generated by "scripts/unicode.py", do not edit directly

#![allow(missing_docs, non_upper_case_globals, non_snake_case)]
'''

UNICODE_VERSION = (12, 1, 0)

UNICODE_VERSION_NUMBER = "%s.%s.%s" %UNICODE_VERSION

def fetch(f):
    if not os.path.exists(os.path.basename(f)):
        os.system("curl -O http://www.unicode.org/Public/security/%s/%s"
                  % (UNICODE_VERSION_NUMBER, f))

    if not os.path.exists(os.path.basename(f)):
        sys.stderr.write("cannot load %s\n" % f)
        exit(1)

# Implementation from unicode-segmentation
def load_properties(f, interestingprops = None):
    fetch(f)
    props = {}
    re1 = re.compile(r"^ *([0-9A-F]+) *; *(\w+)")
    re2 = re.compile(r"^ *([0-9A-F]+)\.\.([0-9A-F]+) *; *(\w+)")

    for line in fileinput.input(os.path.basename(f)):
        prop = None
        d_lo = 0
        d_hi = 0
        m = re1.match(line)
        if m:
            d_lo = m.group(1)
            d_hi = m.group(1)
            prop = m.group(2).strip()
        else:
            m = re2.match(line)
            if m:
                d_lo = m.group(1)
                d_hi = m.group(2)
                prop = m.group(3).strip()
            else:
                continue
        if interestingprops and prop not in interestingprops:
            continue
        d_lo = int(d_lo, 16)
        d_hi = int(d_hi, 16)
        if prop not in props:
            props[prop] = []
        props[prop].append((d_lo, d_hi))

    return props

def format_table_content(f, content, indent):
    line = " "*indent
    first = True
    for chunk in content.split(","):
        if len(line) + len(chunk) < 98:
            if first:
                line += chunk
            else:
                line += ", " + chunk
            first = False
        else:
            f.write(line + ",\n")
            line = " "*indent + chunk
    f.write(line)

def escape_char(c):
    return "'\\u{%x}'" % c

def emit_table(f, name, t_data, t_type = "&'static [(char, char)]", is_pub=True,
        pfun=lambda x: "(%s,%s)" % (escape_char(x[0]), escape_char(x[1])), is_const=True):
    pub_string = "const"
    if not is_const:
        pub_string = "let"
    if is_pub:
        pub_string = "pub " + pub_string
    f.write("    %s %s: %s = &[\n" % (pub_string, name, t_type))
    data = ""
    first = True
    for dat in t_data:
        if not first:
            data += ","
        first = False
        data += pfun(dat)
    format_table_content(f, data, 8)
    f.write("\n    ];\n\n")

def emit_identifier_module(f):
    f.write("pub mod identifier {")
    f.write("""

    #[derive(Copy, Clone, Hash, Eq, PartialEq, Ord, PartialOrd, Debug)]
    #[allow(non_camel_case_types)]
    /// https://www.unicode.org/reports/tr39/#Identifier_Status_and_Type
    pub enum IdentifierType {
        // Restricted
        Not_Character,
        Deprecated,
        Default_Ignorable,
        Not_NFKC,
        Not_XID,
        Exclusion,
        Obsolete,
        Technical,
        Uncommon_Use,
        Limited_Use,

        // Allowed
        Inclusion,
        Recommended
    }
    #[inline]
    pub fn identifier_status_allowed(c: char) -> bool {
        // FIXME: do we want to special case ASCII here?
        match c as usize {
            _ => super::util::bsearch_range_table(c, IDENTIFIER_STATUS)
        }
    }

    #[inline]
    pub fn identifier_type(c: char) -> Option<IdentifierType> {
        // FIXME: do we want to special case ASCII here?
        match c as usize {
            _ => super::util::bsearch_range_value_table(c, IDENTIFIER_TYPE)
        }
    }
""")

    f.write("    // Identifier status table:\n")
    identifier_status_table = load_properties("IdentifierStatus.txt")
    emit_table(f, "IDENTIFIER_STATUS", identifier_status_table['Allowed'], "&'static [(char, char)]", is_pub=False,
            pfun=lambda x: "(%s,%s)" % (escape_char(x[0]), escape_char(x[1])))
    identifier_type = load_properties("IdentifierType.txt")
    type_table = []
    for ty in identifier_type:
        type_table.extend([(x, y, ty) for (x, y) in identifier_type[ty]])
    
    type_table.sort(key=lambda w: w[0])

    emit_table(f, "IDENTIFIER_TYPE", type_table, "&'static [(char, char, IdentifierType)]", is_pub=False,
            pfun=lambda x: "(%s,%s, IdentifierType::%s)" % (escape_char(x[0]), escape_char(x[1]), x[2]))
    f.write("}\n\n")

def emit_util_mod(f):
    f.write("""
pub mod util {
    use core::result::Result::{Ok, Err};
    #[inline]
    pub fn bsearch_range_table(c: char, r: &'static [(char,char)]) -> bool {
        use core::cmp::Ordering::{Equal, Less, Greater};
        r.binary_search_by(|&(lo,hi)| {
            if lo <= c && c <= hi { Equal }
            else if hi < c { Less }
            else { Greater }
        }).is_ok()
    }
    
    pub fn bsearch_range_value_table<T: Copy>(c: char, r: &'static [(char, char, T)]) -> Option<T> {
        use core::cmp::Ordering::{Equal, Less, Greater};
        match r.binary_search_by(|&(lo, hi, _)| {
            if lo <= c && c <= hi { Equal }
            else if hi < c { Less }
            else { Greater }
        }) {
            Ok(idx) => {
                let (_, _, cat) = r[idx];
                Some(cat)
            }
            Err(_) => None
        }
    }

}

""")

if __name__ == "__main__":
    r = "tables.rs"
    if os.path.exists(r):
        os.remove(r)
    with open(r, "w") as rf:
        # write the file's preamble
        rf.write(preamble)

        rf.write("""
/// The version of [Unicode](http://www.unicode.org/)
/// that this version of unicode-security is based on.
pub const UNICODE_VERSION: (u64, u64, u64) = (%s, %s, %s);

""" % UNICODE_VERSION)

        emit_util_mod(rf)
        ### identifier module
        emit_identifier_module(rf)