#!/usr/bin/env bash

PROGRAM_NAME="rokit"
REPOSITORY="rojo-rbx/rokit"

set -eo pipefail

# Make sure we have all the necessary commands available
dependencies=(
    curl
    unzip
    uname
    tr
)

for dep in "${dependencies[@]}"; do
    if ! command -v "$dep" >/dev/null 2>&1; then
        echo "ERROR: '$dep' is not installed or available." >&2
        exit 1
    fi
done

# Warn the user if they are not using a shell we know works (bash, zsh)
if [ -z "$BASH_VERSION" ] && [ -z "$ZSH_VERSION" ]; then
    echo "WARNING: You are using an unsupported shell. Automatic installation may not work correctly." >&2
fi

# Let the user know their access token was detected, if provided
if [ ! -z "$GITHUB_PAT" ]; then
    echo "NOTE: Using provided GITHUB_PAT for authentication"
fi

# Determine OS and architecture for the current system
OS="$(uname -s | tr '[:upper:]' '[:lower:]')"
case "$OS" in
    darwin) OS="macos" ;;
    linux) OS="linux" ;;
    cygwin*|mingw*|msys*) OS="windows" ;;
    *)
        echo "Unsupported OS: $OS" >&2
        exit 1 ;;
esac
ARCH="$(uname -m)"
case "$ARCH" in
    x86_64) ARCH="x86_64" ;;
    x86-64) ARCH="x86_64" ;;
    arm64) ARCH="aarch64" ;;
    aarch64) ARCH="aarch64" ;;
    *)
        echo "Unsupported architecture: $ARCH" >&2;
        exit 1 ;;
esac

# Construct file pattern for our desired zip file based on OS + arch
# NOTE: This only works for exact patterns "binary-X.Y.Z-os-arch.zip"
# and WILL break if the version contains extra metadata / pre-release
VERSION_PATTERN="[0-9]*\\.[0-9]*\\.[0-9]*"
API_URL="https://api.github.com/repos/$REPOSITORY/releases/latest"
if [ ! -z "$1" ]; then
    # Fetch a specific version from given script argument
    VERSION_PATTERN="$1"
    API_URL="https://api.github.com/repos/$REPOSITORY/releases/tags/v$1"
    printf "\n[1 / 3] Looking for $PROGRAM_NAME release with tag 'v$1'\n"
else
    # Fetch the latest release from the GitHub API
    printf "\n[1 / 3] Looking for latest $PROGRAM_NAME release\n"
fi
FILE_PATTERN="${PROGRAM_NAME}-${VERSION_PATTERN}-${OS}-${ARCH}.zip"

# Use curl to fetch the latest release data from GitHub API
if [ ! -z "$GITHUB_PAT" ]; then
    RELEASE_JSON_DATA=$(curl --proto '=https' --tlsv1.2 -sSf "$API_URL" \
        -H "X-GitHub-Api-Version: 2022-11-28" -H "Authorization: token $GITHUB_PAT")
else
    RELEASE_JSON_DATA=$(curl --proto '=https' --tlsv1.2 -sSf "$API_URL" \
        -H "X-GitHub-Api-Version: 2022-11-28")
fi

# Check if the release was fetched successfully
if [ -z "$RELEASE_JSON_DATA" ] || [[ "$RELEASE_JSON_DATA" == *"Not Found"* ]]; then
    echo "ERROR: Latest release was not found. Please check your network connection." >&2
    exit 1
fi

# Try to extract the asset url from the response by searching for a
# matching asset name, and then picking the "url" that came before it
RELEASE_ASSET_ID=""
RELEASE_ASSET_NAME=""
while IFS= read -r current_line; do
    if [[ "$current_line" == *'"url":'* && "$current_line" == *"https://api.github.com/repos/$REPOSITORY/releases/assets/"* ]]; then
        RELEASE_ASSET_ID="${current_line##*/releases/assets/}"
        RELEASE_ASSET_ID="${RELEASE_ASSET_ID%%\"*}"
    elif [[ "$current_line" == *'"name":'* ]]; then
        current_name="${current_line#*: \"}"
        current_name="${current_name%%\"*}"
        if [[ "$current_name" =~ $FILE_PATTERN ]]; then
            if [ -n "$RELEASE_ASSET_ID" ]; then
                RELEASE_ASSET_ID="$RELEASE_ASSET_ID"
                RELEASE_ASSET_NAME="$current_name"
                break
            else
                RELEASE_ASSET_ID=""
            fi
        else
            RELEASE_ASSET_ID=""
        fi
    fi
done <<< "$RELEASE_JSON_DATA"

if [ -z "$RELEASE_ASSET_ID" ] || [ -z "$RELEASE_ASSET_NAME" ]; then
    echo "ERROR: Failed to find asset that matches the pattern \"$FILE_PATTERN\" in the latest release." >&2
    exit 1
fi

# Download the file using curl and make sure it was successful
echo "[2 / 3] Downloading '$RELEASE_ASSET_NAME'"
RELEASE_DOWNLOAD_URL="https://api.github.com/repos/$REPOSITORY/releases/assets/$RELEASE_ASSET_ID"
ZIP_FILE="${RELEASE_ASSET_NAME%.*}.zip"
if [ ! -z "$GITHUB_PAT" ]; then
    curl --proto '=https' --tlsv1.2 -L -o "$ZIP_FILE" -sSf "$RELEASE_DOWNLOAD_URL" \
        -H "X-GitHub-Api-Version: 2022-11-28" -H "Accept: application/octet-stream"  -H "Authorization: token $GITHUB_PAT"
else
    curl --proto '=https' --tlsv1.2 -L -o "$ZIP_FILE" -sSf "$RELEASE_DOWNLOAD_URL" \
        -H "X-GitHub-Api-Version: 2022-11-28" -H "Accept: application/octet-stream"
fi
if [ ! -f "$ZIP_FILE" ]; then
    echo "ERROR: Failed to download the release archive '$ZIP_FILE'." >&2
    exit 1
fi

# Unzip only the specific file we want and make sure it was successful
BINARY_NAME="$PROGRAM_NAME"
if [ "$OS" = "windows" ]; then
    BINARY_NAME="${BINARY_NAME}.exe"
fi
unzip -o -q "$ZIP_FILE" "$BINARY_NAME" -d .
rm "$ZIP_FILE"
if [ ! -f "$BINARY_NAME" ]; then
    echo "ERROR: The file '$BINARY_NAME' does not exist in the downloaded archive." >&2
    exit 1
fi

# Execute the file and remove it when done
printf "[3 / 3] Running $PROGRAM_NAME installation\n\n"
if [ "$OS" != "windows" ]; then
    chmod +x "$BINARY_NAME"
fi
./"$BINARY_NAME" self-install
rm "$BINARY_NAME"