#!/usr/bin/env python
#
import sys
import os

def insert_at(srclines, pos, tag, style):
    if style == '/*':
        srclines.insert(pos, '/* SPDX-License-Identifier: %s */\n' %tag)
    else:
        srclines.insert(pos, '%s SPDX-License-Identifier: %s\n' %(style, tag))
    return True

def handle_c(srclines, tag):
    return insert_at(srclines, 0, tag, '//')

def is_script(srclines):
    for line in srclines:
        line.lstrip();
        if line.startswith('#!'):
            return True;
    return False;

def handle_asm(srclines, tag):
    # Stupid search for a proper style to comment the SPDX tag
    pos = 0
    style = None
    for line in srclines:
        pos += 1
        line.lstrip();
        if line.startswith(';;;'):
            style = ';;;'
        elif line.startswith(';;'):
            style = ';;'
        elif line.startswith(';'):
            style = ';'
        elif line.startswith('|'):
            style = '|'
        elif line.startswith('!'):
            style = '!'
        elif line.startswith('//'):
            style = '//'
        elif line.find("/*") >= 0:
            style = '/*'
        else:
            # default to /* if we have no clue
            style = '/*'
        return insert_at(srclines, 0, tag, style)
    return False

def handle_sh(srclines, tag):
    return insert_at(srclines, 1, tag, '#')

tf = open(sys.argv[1])

for entry in tf.readlines():

    if len(entry.strip()) == 0:
        continue

    nr, fname, tag = entry.strip().split(',')
    # FIXME: Use a proper encoder
    fname = fname.replace('%2C',',')
    fname = fname.replace('%2B','+')
    if tag == 'NOTAG':
        print("Skipping %s" %fname)
        continue

    if not os.path.isfile(fname):
        print("FAIL: File %s does not exist anymore" %fname)
        continue

    bname = os.path.basename(fname)
    
    srclines = open(fname).readlines()

    done = False
    for line in srclines:
        if line.find('SPDX-License-Identifier') >= 0:
            done = True
            break

    if done:
        print("SPDX id exists already in %s" %fname)
        continue

    ok = False
    if fname.endswith('.h') or fname.endswith('.lds'):
        ok = insert_at(srclines, 0, tag, '/*')

    elif fname.endswith('.cpp'):
        ok = insert_at(srclines, 0, tag, '//')

    elif fname.endswith('.c') or fname.endswith('.uc'):
        ok = handle_c(srclines, tag)

    elif fname.endswith('.S'):
        ok = handle_asm(srclines, tag)

    elif fname.endswith('.cocci'):
        ok = insert_at(srclines, 0, tag, '//')
        
    elif fname.endswith('.dts') or fname.endswith('.dtsi'):
        ok = insert_at(srclines, 0, tag, '//')

    elif fname.endswith('.py') or fname.endswith('.tc') or fname.endswith('.sh') or fname.endswith('.pl'):
        ok = insert_at(srclines, 1, tag, '#')

    elif bname.startswith('Makefile') or bname.startswith('Kconfig') or bname.startswith('Kbuild'):
        ok = insert_at(srclines, 0, tag, '#')

    elif is_script(srclines):
        ok = insert_at(srclines, 1, tag, "#")

    else:
        print("Unhandled or ignored file %s" %fname)
        continue

    if ok:
        open(fname, 'w').writelines(srclines)
        print("Inserted %s into %s" %(tag, fname))
    else:
        print("FAIL: No place for insertion found %s" %fname)