#!/bin/bash

# Copyright (c) 2014. The SimGrid Team.
# All rights reserved.

# This program is free software; you can redistribute it and/or modify it
# under the terms of the license (GNU LGPL) which comes with this package.

if [ "$1" = "-t" ]; then
    template=$2
    shift 2
else
    template=$(git rev-parse --show-toplevel)/COPYRIGHT.template
fi

if [ $# -eq 0 ]; then
    cat >&2 <<EOF
Usage: $0 [-t COPYRIGHT.template] files...
EOF
    exit 1
fi

if [ ! -r "$template" ]; then
    printf 'File not found: %s\n' "$template" >&2
    exit 1
fi

printf 'Using template: %s\n' "$template"

now=$(date +%Y)

get_dates() {
    local file=$1
    local date
    sed -n '/Copyright.*SimGrid/{
              s/.*(c) \([[:digit:], -]*\).*/\1/
              s/[, ]\+/\n/g
              p
            }' "$file" \
    | while read date; do
        case "$date" in
            "")
                ;;
            *-*)
                seq ${date/-/ }
                ;;
            *)
                echo $date
                ;;
        esac
    done
    git log --format=%ad "$file" | cut -d\  -f5 | uniq
    echo $now
}

format_dates() {
    local first
    local last
    local next
    read first
    last=$first
    while read next; do
        if [ $next -eq $((last + 1)) ]; then
            last=$next
        else
            if [ $first -eq $last ]; then
                printf '%d, ' $first
            else
                printf '%d-%d, ' $first $last
            fi
            first=$next
            last=$first
        fi
    done
    if [ $first -eq $last ]; then
        printf '%d\n' $first
    else
        printf '%d-%d\n' $first $last
    fi
}

tmp_head=$(mktemp)
tmp_copy=$(mktemp)
tmp_foot=$(mktemp)
trap "rm -f \"$tmp_head\" \"$tmp_copy\" \"$tmp_foot\"" EXIT

for file; do
    echo "########## $file ##########"

    if [ ! -f "$file" ]; then
        echo "!!! skip"
        continue
    fi

    if head -n 1 "$file" | grep -q '^#!'; then
        script=1
    else
        script=0
    fi

    ### 1. create new template
    dates=$(get_dates "$file" | sort -u | format_dates)
    sed "s/(c) [[:digit:], -]*\./(c) $dates./" "$template" > "$tmp_copy"
    printf '\n' >> "$tmp_copy"

    # fix comments for scripts
    if [ $script = 1 ]; then
        sed -i 's!^..!#!;s! *\*/!!' "$tmp_copy"
    fi

    ### 2. copy file body
    if grep -q 'Copyright.*SimGrid' "$file"; then
        sed '/Copyright.*SimGrid/,$d' "$file" > "$tmp_head"
        sed -i '${\!^/\* *$!d}' "$tmp_head"
        sed '1,/the terms of the license/d' "$file" > "$tmp_foot"
    elif [ $script = 1 ]; then
        head -n 1 "$file" > "$tmp_head"
        tail -n +2  "$file" > "$tmp_foot"
        printf '\n' >> "$tmp_head"
    else
        :> "$tmp_head"
        cp "$file" "$tmp_foot"
    fi
    sed -i '1{\!^ *\*/!d};/[^[:space:]]/,$!d' "$tmp_foot"

    ### 3. concatenate new template and file body into $file
#    cat "$tmp_head"
#    cat "$tmp_copy"
#    cat "$tmp_foot"
    cat "$tmp_head" "$tmp_copy" "$tmp_foot" > $file
done

cat <<EOF

All files processed.

*** DO NOT FORGET TO DOUBLE CHECK CHANGES BEFORE DOING ANY COMMIT! ***

EOF