#!/usr/bin/env bash

set -eu

REFERENCE_FILES=(
    # lab 1
    src/mrapps/crash.go
    src/mrapps/indexer.go
    src/mrapps/mtiming.go
    src/mrapps/nocrash.go
    src/mrapps/rtiming.go
    src/mrapps/wc.go
    src/main/mrsequential.go
    src/main/mrmaster.go
    src/main/mrworker.go

    # lab 2
    src/raft/persister.go
    src/raft/test_test.go
    src/raft/config.go
    src/labrpc/labrpc.go

    # lab 3
    src/kvraft/test_test.go
    src/kvraft/config.go

    # lab 4a
    src/shardmaster/test_test.go
    src/shardmaster/config.go

    # lab 4b
    src/shardkv/test_test.go
    src/shardkv/config.go
)

main() {
    upstream="$1"
    labnum="$2"

    # make sure we have reference copy of lab, in FETCH_HEAD
    git fetch "$upstream" 2>/dev/null || die "unable to git fetch $upstream"

    # copy existing directory
    tmpdir="$(mktemp -d)"
    find src -type s -delete # cp can't copy sockets
    cp -r src "$tmpdir"
    orig="$PWD"
    cd "$tmpdir"

    # check out reference files
    for f in ${REFERENCE_FILES[@]}; do
        mkdir -p "$(dirname $f)"
        git --git-dir="$orig/.git" show "FETCH_HEAD:$f" > "$f"
    done

    case $labnum in
        "lab1") check_lab1;;
        "lab2a"|"lab2b"|"lab2c") check_lab2;;
        "lab3a"|"lab3b") check_lab3;;
        "lab4a") check_lab4a;;
        "lab4b") check_lab4b;;
        *) die "unknown lab: $labnum";;
    esac

    cd
    rm -rf "$tmpdir"
}

check_lab1() {
    check_cmd cd src/mrapps
    check_cmd go build -buildmode=plugin wc.go
    check_cmd go build -buildmode=plugin indexer.go
    check_cmd go build -buildmode=plugin mtiming.go
    check_cmd go build -buildmode=plugin rtiming.go
    check_cmd go build -buildmode=plugin crash.go
    check_cmd go build -buildmode=plugin nocrash.go
    check_cmd cd ../main
    check_cmd go build mrmaster.go
    check_cmd go build mrworker.go
    check_cmd go build mrsequential.go
}

check_lab2() {
    check_cmd cd src/raft
    check_cmd go test -c
}

check_lab3() {
    check_cmd cd src/kvraft
    check_cmd go test -c
}

check_lab4a() {
    check_cmd cd src/shardmaster
    check_cmd go test -c
}

check_lab4b() {
    check_cmd cd src/shardkv
    check_cmd go test -c
    # also check other labs/parts
    cd "$tmpdir"
    check_lab4a
    cd "$tmpdir"
    check_lab3
    cd "$tmpdir"
    check_lab2
}

check_cmd() {
    if ! "$@" >/dev/null 2>&1; then
        echo "We tried building your source code with testing-related files reverted to original versions, and the build failed. This copy of your code is preserved in $tmpdir for debugging purposes. Please make sure the code you are trying to hand in does not make changes to test code." >&2
        echo >&2
        echo "The build failed while trying to run the following command:" >&2
        echo >&2
        echo "$ $@" >&2
        echo "  (cwd: ${PWD#$tmpdir/})" >&2
        exit 1
    fi
}

die() {
    echo "$1" >&2
    exit 1
}

main "$@"