#!/usr/bin/env bash

job_artifacts() (
    set -euo pipefail

    nix-build-and-cache packages

    # Subsequent `nix build` calls should be fast because the above line ensures
    # the packages have been built already.

    packages=(
        static-aarch64-unknown-linux-musl
        static-x86_64-unknown-linux-musl
    )

    for x in "${packages[@]}"; do
        nix build ".#$x"
        cp result/bin/grapevine grapevine-"$x"
        chmod u+w grapevine-"$x"
    done
)

job_ci() (
    set -euo pipefail

    nix-build-and-cache ci
    direnv exec . engage
)

job_pages() (
    set -euo pipefail

    nix build .#website-root
    cp --recursive --dereference result public
    chmod u+w -R public
)

job_cache-ci-deps() (
    set -euo pipefail

    nix-build-and-cache ci
)

bail() (
    set -euo pipefail

    git show --shortstat
    echo
    echo "Failure caused by the above commit"
    exit 1
)

mark_commit_passed() (
    set -euo pipefail

    mkdir -p ".gitlab-ci.d/passed/$1"
    touch ".gitlab-ci.d/passed/$1/$(git rev-parse HEAD)"
)

commit_passed() (
    set -euo pipefail

    [[ -f ".gitlab-ci.d/passed/$1/$(git rev-parse HEAD)" ]]
)

contains() (
    set -euo pipefail

    local -n xs=$1

    for x in "${xs[@]}"; do
        if [[ "$x" == "$2" ]]; then
            return 0
        else
            return 1
        fi
    done
)

# Jobs that should only run on the latest commit rather than since the branch's
# base.
last_commit_only=(
    artifacts
)

run() (
    set -euo pipefail

    if [[ -z "${1+x}" ]]; then
        echo "You must supply a job to run. Available jobs:"
        declare -F | rg \
            --only-matching \
            --color never \
            --replace '* $1' \
            '^declare -f job_(.*)$'

        exit 1
    fi

    job="$1"

    cd "$(git rev-parse --show-toplevel)"

    if \
        [[ -z "${CI_MERGE_REQUEST_DIFF_BASE_SHA+x}" ]] \
        || contains last_commit_only "$job"
    then
        echo "Running against latest commit only..."

        job_"$job" || bail
    else
        echo "Running against all commits since this branch's base..."

        readarray -t commits < \
            <(git rev-list --reverse "$CI_MERGE_REQUEST_DIFF_BASE_SHA..HEAD")
        for commit in "${commits[@]}"; do
            git checkout "$commit"

            if commit_passed "$job"; then
                echo "Skipping commit because it already passed: $commit"
                continue
            fi

            job_"$job" || bail

            mark_commit_passed "$job"
        done
    fi
)

run "$@"