#!/usr/bin/env bash

range="$1"
cmd="$2"
curbranch=$(git rev-parse --abbrev-ref HEAD)
rev=${3:-${curbranch}}
sit=$(which sit)

if [ -z "${range}" ] || [ -z "${cmd}" ]; then
        echo "Usage: $0 COMMIT_RANGE COMMAND [REV]"
        exit 1
fi

if [ -z "${sit}" ]; then
        echo "sit not found"
        exit 1
fi

target_rev=$(git rev-parse "${range}" | head -1)

report_branch="ci-$(date +'%s')"
sit_path=$(${sit} path)
files=$(git diff --name-only ${range} | sort)

failed_patch () {
        mkdir -p "${sit_path}/items/$1"
        tmp_dir=$(mktemp -d)
        pushd $(pwd) >/dev/null
        cd "${tmpdir}"

        echo $2 > record
        echo "Failed to apply merge request $2 against revision $4" > text
        ${sit} -r ${sit_path} record -t Commented,MergeRequestVerificationFailed $1 text record || exit 2
        popd >/dev/null

        rm -rf ${tmp_dir}
}

failed_ci () {
        mkdir -p "${sit_path}/items/$1"
        tmp_dir=$(mktemp -d)
        pushd $(pwd) >/dev/null
        cd "${tmpdir}"

        echo $2 > record
        printf "Merge request $2 failed against revision $3\n<details><summary>Log</summary><p>\`\`\`\n$4\`\`\`\n</p></details>" > text
        ${sit} -r ${sit_path} record -t Commented,MergeRequestVerificationFailed $1 text record || exit 2
        popd >/dev/null

        rm -rf ${tmp_dir}
}

passed_ci () {
        mkdir -p "${sit_path}/items/$1"
        tmp_dir=$(mktemp -d)
        pushd $(pwd) >/dev/null
        cd "${tmpdir}"

        echo $2 > record
        printf "Merge request $2 passed against revision $3\n<details><summary>Log</summary><p>\`\`\`\n$4\`\`\`\n</p></details>" > text
        ${sit} -r ${sit_path} record -t Commented,MergeRequestVerificationSucceeded $1 text record || exit 2
        popd >/dev/null

        rm -rf ${tmp_dir}
}

check_mr () {
        git_regex="^\.sit/items/$1/$2/git/.+\.patch"
        git checkout -b "${report_branch}-${item}-${mr}" "${rev}"
        # Apply patches
        for file in ${files}; do
                if [[ "${file}" =~ ${git_regex} ]]; then
                        git show "${target_rev}":${file} | git am || (git am --abort; failed_patch $1 $2 "${file}" "${rev}")
                fi
        done
        # Check
        output=$(${cmd} | tee /dev/tty)
        result=$?
        if [ $result -eq 0 ]; then
                passed_ci $1 $2 "${rev}" "${output}"
        else
                failed_ci $1 $2 "${rev}" "${output}"
        fi
        # Clean up
        git reset --hard
        git checkout "${curbranch}"
        git branch -D "${report_branch}-${item}-${mr}"
}

reported_items=""

for file in ${files}; do
        if [[ "${file}" =~ ^\.sit/items/.+/.+/\.type/MergeRequested$ ]]; then
                item=$(echo ${file} | sed -E "s/\.sit\/items\/([^\/]+)\/.*/\1/")
                mr=$(echo ${file} | sed -E "s/\.sit\/items\/[^\/]+\/([^\/]+)\/.*/\1/")
                echo "Found merge request ${item}/${mr}" 1>&2
                check_mr "${item}" "${mr}"
                reported_items="${reported_items} ${item}"
        fi
done

git checkout -b "${report_branch}"

for report in ${reported_items}; do
        git add ${sit_path}/items/${report}
done

git commit -m "CI report"

git checkout "${curbranch}"

# This branch can be now sent to the repository via inbox
# or any other means
echo "${report_branch}"