#!/usr/bin/env bash

if [[ -z "${IN_NIX_SHELL}" ]]; then
    echo "Remember to call 'make shell'!"
    exit 1
fi

# This script takes care of generating/updating the maven-sources.nix file
# representing the offline Maven repo containing the dependencies
# required to build the project

GIT_ROOT=$(cd "${BASH_SOURCE%/*}" && git rev-parse --show-toplevel)
THIS_SCRIPT=$(realpath --relative-to="${GIT_ROOT}" ${BASH_SOURCE})
CUR_DIR=$(cd "${BASH_SOURCE%/*}" && pwd)
source "${GIT_ROOT}/scripts/colors.sh"

PROJ_LIST="${CUR_DIR}/proj.list"
DEPS_LIST="${CUR_DIR}/deps.list"
DEPS_URLS="${CUR_DIR}/deps.urls"
DEPS_NIX="${CUR_DIR}/deps.nix"

# Raise limit of file descriptors
ulimit -n 16384

# This needs to be used by all instances of determine_url.sh
# but needs to be fresh on every run of generate.sh.
# Helps mvn not re-download same stuff over and over again.
export MVN_REPO_CACHE='/tmp/maven-repo-cache'
trap "rm -rf ${MVN_REPO_CACHE}" ERR EXIT HUP INT

echo "Regenerating Nix files..."

# Gradle needs to be run in 'android' subfolder
cd $GIT_ROOT/android

# Stop gradle daemons to avoid locking
./gradlew --stop >/dev/null

# Generate list of Gradle sub-projects ----------------------------------------
${CUR_DIR}/get_projects.sh | sort -u -o ${PROJ_LIST}

echo -e "Found ${GRN}$(wc -l < ${PROJ_LIST})${RST} sub-projects..."

# Check each sub-project in parallel, the ":" is for local deps ---------------
PROJECTS=$(cat ${PROJ_LIST})
${CUR_DIR}/get_deps.sh ":" ${PROJECTS[@]} \
    | sort -uV -o ${DEPS_LIST}

echo -e "\033[2KFound ${GRN}$(wc -l < ${DEPS_LIST})${RST} direct dependencies..."

# Save old URLs file to improve search
if [[ ! -s "${DEPS_URLS}.old" ]] && [[ -s "${DEPS_URLS}" ]]; then
    mv "${DEPS_URLS}" "${DEPS_URLS}.old"
fi

# Find download URLs for each dependency --------------------------------------
# The AWK call removes duplicates using different repos.
DEPENDENCIES=$(cat ${DEPS_LIST})
parallel --will-cite \
    ${CUR_DIR}/get_urls.sh \
    ::: ${DEPENDENCIES[@]} \
    | awk -F'/' '{db[$NF]++;if(db[$NF]==1){print}}' \
    | sort -uV -o ${DEPS_URLS}

echo -e "\033[2KFound ${GRN}$(wc -l < ${DEPS_URLS})${RST} dependency URLs..."

# Open the Nix attribute set --------------------------------------------------
echo -e "# Generated by ${THIS_SCRIPT}\n{" > ${DEPS_NIX}

# Format URLs into a Nix consumable file.
URLS=$(cat ${DEPS_URLS})
parallel --will-cite --keep-order \
    "${CUR_DIR}/url2nix.sh" \
    ::: ${URLS} \
    >> ${DEPS_NIX}

# Close the Nix attribute set
echo "}" >> ${DEPS_NIX}

echo -e "\033[2KGenerated Nix deps file: ${DEPS_NIX}"
echo -e "${GRN}Done${RST}"