#!/usr/bin/env bash

# This script is used to download built dashboard assets from the "GreptimeTeam/dashboard" repository.
set -ex

declare -r SCRIPT_DIR=$(cd $(dirname ${0}) >/dev/null 2>&1 && pwd)
declare -r ROOT_DIR=$(dirname ${SCRIPT_DIR})
declare -r STATIC_DIR="$ROOT_DIR/src/servers/dashboard"
OUT_DIR="${1:-$SCRIPT_DIR}"

RELEASE_VERSION="$(cat $STATIC_DIR/VERSION | tr -d '\t\r\n ')"

echo "Downloading assets to dir: $OUT_DIR"
cd $OUT_DIR

if [[ -z "$GITHUB_PROXY_URL" ]]; then
  GITHUB_URL="https://github.com"
else
  GITHUB_URL="${GITHUB_PROXY_URL%/}"
fi

function retry_fetch() {
    local url=$1
    local filename=$2

    curl --connect-timeout 10 --retry 3 -fsSL $url --output $filename || {
        echo "Failed to download $url"
        echo "You may try to set http_proxy and https_proxy environment variables."
        if [[ -z "$GITHUB_PROXY_URL" ]]; then
          echo "You may try to set GITHUB_PROXY_URL=http://mirror.ghproxy.com/https://github.com/"
        fi
        exit 1
     }
}

# Download the SHA256 checksum attached to the release. To verify the integrity
# of the download, this checksum will be used to check the download tar file
# containing the built dashboard assets.
retry_fetch "${GITHUB_URL}/GreptimeTeam/dashboard/releases/download/${RELEASE_VERSION}/sha256.txt" sha256.txt

# Download the tar file containing the built dashboard assets.
retry_fetch "${GITHUB_URL}/GreptimeTeam/dashboard/releases/download/${RELEASE_VERSION}/build.tar.gz" build.tar.gz

# Verify the checksums match; exit if they don't.
case "$(uname -s)" in
    FreeBSD | Darwin)
        echo "$(cat sha256.txt)" | shasum --algorithm 256 --check \
            || { echo "Checksums did not match for downloaded dashboard assets!"; exit 1; } ;;
    Linux)
        echo "$(cat sha256.txt)" | sha256sum --check -- \
            || { echo "Checksums did not match for downloaded dashboard assets!"; exit 1; } ;;
    *)
        echo "The '$(uname -s)' operating system is not supported as a build host for the dashboard" >&2
        exit 1
esac

# Extract the assets and clean up.
tar -xzf build.tar.gz -C "$STATIC_DIR"
rm sha256.txt
rm build.tar.gz

echo "Successfully download dashboard assets to $STATIC_DIR"