#!/usr/bin/env bash

stderr() {

    echo "$@" 1>&2

}

usage() {

    b=$(basename "$0")

    echo $b: ERROR: "$@" 1>&2

    cat 1>&2 <<EOF

DESCRIPTION

    $(basename "$0") is the script to run continuous integration commands for

    go-toml on unix.

    Requires Go and Git to be available in the PATH. Expects to be ran from the

    root of go-toml's Git repository.

USAGE

    $b COMMAND [OPTIONS...]

COMMANDS

benchmark [OPTIONS...] [BRANCH]

    Run benchmarks.

    ARGUMENTS

        BRANCH Optional. Defines which Git branch to use when running

               benchmarks.

    OPTIONS

        -d      Compare benchmarks of HEAD with BRANCH using benchstats. In

                this form the BRANCH argument is required.

        -a      Compare benchmarks of HEAD against go-toml v1 and

                BurntSushi/toml.

        -html   When used with -a, emits the output as HTML, ready to be

                embedded in the README.

coverage [OPTIONS...] [BRANCH]

    Generates code coverage.

    ARGUMENTS

        BRANCH  Optional. Defines which Git branch to use when reporting

                coverage. Defaults to HEAD.

    OPTIONS

        -d      Compare coverage of HEAD with the one of BRANCH. In this form,

                the BRANCH argument is required. Exit code is non-zero when

                coverage percentage decreased.

EOF

    exit 1

}

cover() {

    branch="${1}"

    dir="$(mktemp -d)"

    stderr "Executing coverage for ${branch} at ${dir}"

    if [ "${branch}" = "HEAD" ]; then

	    cp -r . "${dir}/"

    else

	    git worktree add "$dir" "$branch"

    fi

    pushd "$dir"

    go test -covermode=atomic  -coverpkg=./... -coverprofile=coverage.out.tmp ./...

    cat coverage.out.tmp | grep -v testsuite | grep -v tomltestgen | grep -v gotoml-test-decoder > coverage.out

    go tool cover -func=coverage.out

    popd

    if [ "${branch}" != "HEAD" ]; then

	    git worktree remove --force "$dir"

    fi

}

coverage() {

    case "$1" in

	-d)

	    shift

	    target="${1?Need to provide a target branch argument}"

	    output_dir="$(mktemp -d)"

	    target_out="${output_dir}/target.txt"

	    head_out="${output_dir}/head.txt"

	    cover "${target}" > "${target_out}"

	    cover "HEAD" > "${head_out}"

	    cat "${target_out}"

	    cat "${head_out}"

	    echo ""

	    target_pct="$(tail -n2 ${target_out} | head -n1 | sed -E 's/.*total.*\t([0-9.]+)%.*/\1/')"

	    head_pct="$(tail -n2 ${head_out} | head -n1 | sed -E 's/.*total.*\t([0-9.]+)%/\1/')"

	    echo "Results: ${target} ${target_pct}% HEAD ${head_pct}%"

	    delta_pct=$(echo "$head_pct - $target_pct" | bc -l)

	    echo "Delta: ${delta_pct}"

	    if [[ $delta_pct = \-* ]]; then

		    echo "Regression!";

            target_diff="${output_dir}/target.diff.txt"

            head_diff="${output_dir}/head.diff.txt"

            cat "${target_out}" | grep -E '^github.com/pelletier/go-toml' | tr -s "\t " | cut -f 2,3 | sort > "${target_diff}"

            cat "${head_out}" | grep -E '^github.com/pelletier/go-toml' | tr -s "\t " | cut -f 2,3 | sort > "${head_diff}"

            diff --side-by-side --suppress-common-lines "${target_diff}" "${head_diff}"

		    return 1

	    fi

	    return 0

	    ;;

    esac

    cover "${1-HEAD}"

}

bench() {

    branch="${1}"

    out="${2}"

    replace="${3}"

    dir="$(mktemp -d)"

    stderr "Executing benchmark for ${branch} at ${dir}"

    if [ "${branch}" = "HEAD" ]; then

    	cp -r . "${dir}/"

    else

	    git worktree add "$dir" "$branch"

    fi

    pushd "$dir"

    if [ "${replace}" != "" ]; then

        find ./benchmark/ -iname '*.go' -exec sed -i -E "s|github.com/pelletier/go-toml/v2|${replace}|g" {} \;

        go get "${replace}"

    fi

    export GOMAXPROCS=2

    nice -n -19 taskset --cpu-list 0,1 go test '-bench=^Benchmark(Un)?[mM]arshal' -count=5 -run=Nothing ./... | tee "${out}"

    popd

    if [ "${branch}" != "HEAD" ]; then

	    git worktree remove --force "$dir"

    fi

}

fmktemp() {

    if mktemp --version|grep GNU >/dev/null; then

        mktemp --suffix=-$1;

    else

        mktemp -t $1;

    fi

}

benchstathtml() {

python3 - $1 <<'EOF'

import sys

lines = []

stop = False

with open(sys.argv[1]) as f:

    for line in f.readlines():

        line = line.strip()

        if line == "":

            stop = True

        if not stop:

            lines.append(line.split(','))

results = []

for line in reversed(lines[1:]):

    v2 = float(line[1])

    results.append([

        line[0].replace("-32", ""),

        "%.1fx" % (float(line[3])/v2),  # v1

        "%.1fx" % (float(line[5])/v2),  # bs

    ])

# move geomean to the end

results.append(results[0])

del results[0]

def printtable(data):

    print("""

<table>

    <thead>

        <tr><th>Benchmark</th><th>go-toml v1</th><th>BurntSushi/toml</th></tr>

    </thead>

    <tbody>""")

    for r in data:

        print("        <tr><td>{}</td><td>{}</td><td>{}</td></tr>".format(*r))

    print("""     </tbody>

</table>""")

def match(x):

    return "ReferenceFile" in x[0] or "HugoFrontMatter" in x[0]

above = [x for x in results if match(x)]

below = [x for x in results if not match(x)]

printtable(above)

print("<details><summary>See more</summary>")

print("""<p>The table above has the results of the most common use-cases. The table below

contains the results of all benchmarks, including unrealistic ones. It is

provided for completeness.</p>""")

printtable(below)

print('<p>This table can be generated with <code>./ci.sh benchmark -a -html</code>.</p>')

print("</details>")

EOF

}

benchmark() {

    case "$1" in

    -d)

        shift

     	target="${1?Need to provide a target branch argument}"

        old=`fmktemp ${target}`

        bench "${target}" "${old}"

        new=`fmktemp HEAD`

        bench HEAD "${new}"

        benchstat "${old}" "${new}"

        return 0

        ;;

    -a)

        shift

        v2stats=`fmktemp go-toml-v2`

        bench HEAD "${v2stats}" "github.com/pelletier/go-toml/v2"

        v1stats=`fmktemp go-toml-v1`

        bench HEAD "${v1stats}" "github.com/pelletier/go-toml"

        bsstats=`fmktemp bs-toml`

        bench HEAD "${bsstats}" "github.com/BurntSushi/toml"

        cp "${v2stats}" go-toml-v2.txt

        cp "${v1stats}" go-toml-v1.txt

        cp "${bsstats}" bs-toml.txt

        if [ "$1" = "-html" ]; then

            tmpcsv=`fmktemp csv`

            benchstat -csv -geomean go-toml-v2.txt go-toml-v1.txt bs-toml.txt > $tmpcsv

            benchstathtml $tmpcsv

        else

            benchstat -geomean go-toml-v2.txt go-toml-v1.txt bs-toml.txt

        fi

        rm -f go-toml-v2.txt go-toml-v1.txt bs-toml.txt

        return $?

    esac

    bench "${1-HEAD}" `mktemp`

}

case "$1" in

    coverage) shift; coverage $@;;

    benchmark) shift; benchmark $@;;

    *) usage "bad argument $1";;

esac