#!/bin/bash

# This script collates gcov data after one has configured with --enable-gcov,
# built, and run tests.  It either outputs or POSTs to Coveralls a JSON text in
# the schema for the Coveralls API, which is documented here:
#
# https://docs.coveralls.io/api-introduction
# https://docs.coveralls.io/api-reference
#
# Currently only files in source languages supported by gcov(1) are reported
# on, though this can easily be extended.  Currently that's only C/C++ files.
#
# This script is specifically written for Heimdal, which is an open source C
# codebases that uses autoconf and libtool for its build system.  This means
# that sometimes the gcov notes and data files are not necessarily where the
# gcov(1) utility would find them, which is why this script exists instead of
# using some other integration script.
#
# Although this is specific to Heimdal, it can be extended.
#
# Note that one side effect of running this script, gcov(1) will be run for all
# C/C++ source files in the workspace.  As well, some gcov notes and data files
# maybe hard-linked to other names.  However, this script should be idempotent.

set -euo pipefail
set +o noglob

PROG=${0##*/}

job=${TRAVIS_JOB_ID:-}
out=
post=false
repo=
flst=
quiet=false
branch=
srcdir=$PWD
objdir=
token=${COVERALLS_REPO_TOKEN:-}
origin=
verbose=0

function usage {
    ((${1:-1})) && exec 1>&2
    cat <<EOF
Usage: $PROG [OPTIONS]
    Options:

     -q         Quiet.  Do not even emit warnings.
     -v         Verbose (on stderr).  May be given multiple times.
     -o -       Output to stdout instead of POSTing to Coveralls.
     -o FILE    Output to FILE   instead of POSTing to Coveralls.
     -s CI-NAME Name of CI (e.g., "travis-ci")
                Defaults to travis-ci.
     -t TOKEN   Token for Coveralls.
                Defaults to \$COVERALLS_REPO_TOKEN.
     -b BRANCH  Name of branch the report is for.
                Defaults to \$TRAVIS_BRANCH or currently-checked out branch in
                SRCDIR.
     -J ID      Job ID (e.g., Travis-CI job ID)
                Defaults to \${TRAVIS_JOB_ID}.
     -i FILE    Lists source files to run gcov(1) against
                Defaults to \<(git ls-files -- '*.c' '*.cpp').
     -S SRCDIR  Path to workspace
                Defaults to \${PWD}.
     -O OBJDIR  Path to object directory if workspace is built out of tree
                Defaults to SRCDIR.
     -U ORIGIN  Name of origin.
                Defaults to tracked upstream remote of BRANCH.
     -R URI     Repository URI
                Defaults to git@github.com:\${TRAVIS_REPO_SLUG} or the push URI
                for the ORIGIN remote of the workspace at SRCDIR.

    $PROG will look for .gcno and .gcda files in OBJDIR for source files
    in the workspace at SRCDIR and will run gcov on them, and produce
    a request body as JSON in FILE (or stdout if -o FILE not given)
    for the Coveralls API.

    If -o FILE is not given, then $PROG will POST the JSON to Coveralls.
    If -o FILE is given, then $PROG will not POST it to Coveralls.

    If SRCDIR == OBJDIR == \$PWD, then -S and -O need not be given.
    If running in a Travis-CI build, -J, -R, and -b need not be given, and -t
    should not be given -- instead you should set a secret COVERALLS_REPO_TOKEN
    environment variable in your project's Travis-CI's settings.

    Only C and C++ source files are reported on.  E.g., Yacc/Bison/Flex
    source files are not reported.

    The resulting JSON output is or can be POSTed to Coveralls with:

      $ curl -sfg -X POST -F "json_file=@\${FILE}" -F "Filename=json_file" \\
             https://coveralls.io/api/v1/jobs
EOF
    exit ${1:-1}
}

while getopts +:J:O:R:S:U:b:hi:o:qs:t:vx opt; do
case "$opt" in
J) job=$OPTARG;;
O) cd "$OPTARG"; objdir=$PWD; cd "$OLDPWD";;
R) repo=$OPTARG;;
S) cd "$OPTARG"; srcdir=$PWD; cd "$OLDPWD";;
U) origin=$OPTARG;;
b) branch=;;
h) usage 0;;
i) flst=$OPTARG;;
o) out=$OPTARG;;
q) quiet=true; verbose=0;;
s) ci=$OPTARG;;
t) token=$OPTARG;;
v) quiet=false; ((verbose++)) || true; ((verbose > 3)) && set -vx;;
*) usage 1;;
esac
done

# Note: we don't cd to $srcdir or $objdir or anywhere, so if $out is a relative
# path, we do the right thing.

: ${objdir:=${srcdir}}
: ${branch:=${TRAVIS_BRANCH:-$(cd "$srcdir" && git rev-parse --abbrev-ref HEAD)}}

if [[ -z ${origin:-} ]]; then
    origin=$(
        git for-each-ref \
            --format="%(refname:short) %(upstream:remotename)" refs/heads |
            while read gb gr; do
                [[ $gb = $branch ]] || continue
                printf '%s\n' "$gr"
                break
            done
    )
fi

if [[ -z ${repo:-} ]]; then
    if [[ -n ${TRAVIS_REPO_SLUG:-} ]]; then
        repo=git@github.com:${TRAVIS_REPO_SLUG:-heimdal/heimdal}
    else
        repo=$(cd "$srcdir" && git remote get-url --push "$origin")
    fi
fi

if ((verbose > 1)); then
    exec 3>&2
else
    exec 3>/dev/null
fi

d=
function cleanup {
    [[ -n $d ]] && rm -rf "$d"
}

trap cleanup EXIT
d=$(mktemp -d)
touch "${d}/f"

declare -a gcov

(cd "$srcdir" &&
 if [[ -n $flst ]]; then cat "$flst"; else git ls-files -- '*.c' '*.cpp'; fi) |
while read f; do
    # Remember to be careful to refer to ${srcdir}/${f}
    ((verbose)) && printf 'Processing: %s\n' "$f" 1>&2

    dir=${f%/*}
    base=${f##*/}
    base=${base%.*}

    if [[ ! -f ${objdir}/${dir}/.libs/${base}.gcda && ! -f ${objdir}/${dir}/${base}.gcda ]]; then
        # Look for .libs/libfoo_la-${base}.gcda -- we don't know "foo", and
        # there may be more than one!
        gcda=
        for gcda in ${objdir}/${dir}/.libs/*_la-${base}.gcda; do
            break
        done
        gcno=
        for gcno in ${objdir}/${dir}/.libs/*_la-${base}.gcno; do
            break
        done
        [[ -n $gcno && -f $gcno ]] && ln -f "$gcno" "${objdir}/${dir}/.libs/${base}.gcno"
        [[ -n $gcda && -f $gcda ]] && ln -f "$gcda" "${objdir}/${dir}/.libs/${base}.gcda"
        if [[ ( -n $gcda && ! -f $gcda ) || ( -n $gcno && ! -f $gcno ) ]]; then
            $quiet || printf 'Warning: %s has no gcov notes file\n' "$f" 1>&2
            continue
        fi
    fi

    if [[ -f ${objdir}/${dir}/.libs/${base}.gcda ]]; then
        ((verbose > 1)) && printf 'Running gcov for %s using gcda from .libs\n' "$f" 1>&2
        if ! (cd "${objdir}/${f%/*}"; ((verbose > 2)) && set -vx; gcov -o .libs "${f##*/}") 1>&3; then
            $quiet || printf 'Warning: gcov failed for %s\n' "$f" 1>&2
            continue
        fi
    elif [[ -f ${objdir}/${dir}/${base}.gcda ]]; then
        if ! (cd "${objdir}/${f%/*}"; ((verbose > 2)) && set -vx; gcov "${f##*/}") 1>&3; then
            $quiet || printf 'Warning: gcov failed for %s\n' "$f" 1>&2
            continue
        fi
    fi

    if [[ ! -f ${objdir}/${f}.gcov ]]; then
        $quiet || printf 'Warning: gcov did not produce a .gcov file for %s\n' "$f" 1>&2
        continue
    fi

    md5=$(md5sum "${srcdir}/${f}")
    md5=${md5%% *}

    jq -Rn --arg sum "${md5}" --arg f "$f" '
        {
            name: $f,
            source_digest: $sum,
            coverage: [
                inputs
              | split(":")
              | (.[1] |= tonumber)
              | select(.[1] > 0)
              | if .[0]|endswith("#")
                then 0
                elif .[0]|endswith("-")
                then null
                else .[0]|tonumber
                end
            ]
        }
    ' "${objdir}/${f}.gcov" >> "${d}/f"
done

function make_report {
    jq -s --arg job "$job" \
          --arg ci "${ci:-travis-ci}" \
          --arg token "$token" \
          --arg repo "$repo" \
          --arg branch "$branch" \
          --arg upstream "$origin" \
          --arg head "$(git log -n1 --format=%H)" \
          --arg subject "$(git log -n1 --format=%s)" \
          --arg aN "$(git log -n1 --format=%aN)" \
          --arg ae "$(git log -n1 --format=%ae)" \
          --arg cN "$(git log -n1 --format=%cN)" \
          --arg ce "$(git log -n1 --format=%ce)" \
        '{
            service_job_id: $job,
            service_name: $ci,
            repo_token: $token,
            git: {
                id: $head,
                author_name:  $aN,
                author_email: $ae,
                committer_name:  $cN,
                committer_email: $ce,
                message: $subject,
                branch: $branch,
                remotes: [ {
                    "name": $upstream,
                    "url": $repo
                    }
                ]
            },
            source_files: .
        }' "${d}/f"
}

if [[ -z $out ]]; then
    post=true
    make_report > "${d}/out"
elif [[ $out = - ]]; then
    make_report
else
    make_report > "${out}"
fi

if $post && [[ $out != /dev/stdout ]]; then
    curl -sfg -X POST -F "json_file=@${d}/out" -F "Filename=json_file" \
         https://coveralls.io/api/v1/jobs
fi