#! /usr/bin/env python3

"""Show file statistics by extension."""

import os
import sys


class Stats:

 def __init__(self):
 self.stats = {}

 def statargs(self, args):
 for arg in args:
 if os.path.isdir(arg):
 self.statdir(arg)
 elif os.path.isfile(arg):
 self.statfile(arg)
 else:
 sys.stderr.write("Can't find %s\n" % arg)
 self.addstats("<???>", "unknown", 1)

 def statdir(self, dir):
 self.addstats("<dir>", "dirs", 1)
 try:
 names = os.listdir(dir)
 except OSError as err:
 sys.stderr.write("Can't list %s: %s\n" % (dir, err))
 self.addstats("<dir>", "unlistable", 1)
 return
 for name in sorted(names):
 if name.startswith(".#"):
 continue # Skip CVS temp files
 if name.endswith("~"):
 continue # Skip Emacs backup files
 full = os.path.join(dir, name)
 if os.path.islink(full):
 self.addstats("<lnk>", "links", 1)
 elif os.path.isdir(full):
 self.statdir(full)
 else:
 self.statfile(full)

 def statfile(self, filename):
 head, ext = os.path.splitext(filename)
 head, base = os.path.split(filename)
 if ext == base:
 ext = "" # E.g. .cvsignore is deemed not to have an extension
 ext = os.path.normcase(ext)
 if not ext:
 ext = "<none>"
 self.addstats(ext, "files", 1)
 try:
 with open(filename, "rb") as f:
 data = f.read()
 except IOError as err:
 sys.stderr.write("Can't open %s: %s\n" % (filename, err))
 self.addstats(ext, "unopenable", 1)
 return
 self.addstats(ext, "bytes", len(data))
 if b'0円' in data:
 self.addstats(ext, "binary", 1)
 return
 if not data:
 self.addstats(ext, "empty", 1)
 # self.addstats(ext, "chars", len(data))
 lines = str(data, "latin-1").splitlines()
 self.addstats(ext, "lines", len(lines))
 del lines
 words = data.split()
 self.addstats(ext, "words", len(words))

 def addstats(self, ext, key, n):
 d = self.stats.setdefault(ext, {})
 d[key] = d.get(key, 0) + n

 def report(self):
 exts = sorted(self.stats)
 # Get the column keys
 columns = {}
 for ext in exts:
 columns.update(self.stats[ext])
 cols = sorted(columns)
 colwidth = {}
 colwidth["ext"] = max(map(len, exts))
 minwidth = 6
 self.stats["TOTAL"] = {}
 for col in cols:
 total = 0
 cw = max(minwidth, len(col))
 for ext in exts:
 value = self.stats[ext].get(col)
 if value is None:
 w = 0
 else:
 w = len("%d" % value)
 total += value
 cw = max(cw, w)
 cw = max(cw, len(str(total)))
 colwidth[col] = cw
 self.stats["TOTAL"][col] = total
 exts.append("TOTAL")
 for ext in exts:
 self.stats[ext]["ext"] = ext
 cols.insert(0, "ext")

 def printheader():
 for col in cols:
 print("%*s" % (colwidth[col], col), end=' ')
 print()

 printheader()
 for ext in exts:
 for col in cols:
 value = self.stats[ext].get(col, "")
 print("%*s" % (colwidth[col], value), end=' ')
 print()
 printheader() # Another header at the bottom


def main():
 args = sys.argv[1:]
 if not args:
 args = [os.curdir]
 s = Stats()
 s.statargs(args)
 s.report()


if __name__ == "__main__":
 main()