#!/bin/bash

# Initialize variables
script="./scripts/run_validator.sh"
validator_pm2_config="./validator.config.js"
autoRunLoc=$(readlink -f "$0")
proc_name="s1_validator_main_process" 
args=()
version_location="./folding/__init__.py"
version="__version__"

old_args=$@

# Check if pm2 is installed
if ! command -v pm2 &> /dev/null
then
    echo "pm2 could not be found. To install see: https://pm2.keymetrics.io/docs/usage/quick-start/"
    exit 1
fi

# Checks if $1 is smaller than $2
# If $1 is smaller than or equal to $2, then true. 
# else false.
version_less_than_or_equal() {
    [  "$1" = "`echo -e "$1\n$2" | sort -V | head -n1`" ]
}

# Checks if $1 is smaller than $2
# If $1 is smaller than $2, then true. 
# else false.
version_less_than() {
    [ "$1" = "$2" ] && return 1 || version_less_than_or_equal $1 $2
}

# Returns the difference between 
# two versions as a numerical value.
get_version_difference() {
    local tag1="$1"
    local tag2="$2"

    # Extract the version numbers from the tags
    local version1=$(echo "$tag1" | sed 's/v//')
    local version2=$(echo "$tag2" | sed 's/v//')

    # Split the version numbers into an array
    IFS='.' read -ra version1_arr <<< "$version1"
    IFS='.' read -ra version2_arr <<< "$version2"

    # Calculate the numerical difference
    local diff=0
    for i in "${!version1_arr[@]}"; do
        local num1=${version1_arr[$i]}
        local num2=${version2_arr[$i]}

        # Compare the numbers and update the difference
        if (( num1 > num2 )); then
            diff=$((diff + num1 - num2))
        elif (( num1 < num2 )); then
            diff=$((diff + num2 - num1))
        fi
    done

    strip_quotes $diff
}

read_version_value() {
    # Read each line in the file
    while IFS= read -r line; do
        # Check if the line contains the variable name
        if [[ "$line" == *"$version"* ]]; then
            # Extract the value of the variable
            local value=$(echo "$line" | awk -F '=' '{print $2}' | tr -d ' ')
            strip_quotes $value
            return 0
        fi
    done < "$version_location"

    echo ""
}

check_package_installed() {
    local package_name="$1"
    os_name=$(uname -s)
    
    if [[ "$os_name" == "Linux" ]]; then
        # Use dpkg-query to check if the package is installed
        if dpkg-query -W -f='${Status}' "$package_name" 2>/dev/null | grep -q "installed"; then
            return 1
        else
            return 0
        fi
    elif [[ "$os_name" == "Darwin" ]]; then
         if brew list --formula | grep -q "^$package_name$"; then
            return 1
        else
            return 0
        fi
    else
        echo "Unknown operating system"
        return 0
    fi
}

check_variable_value_on_github() {
    local repo="$1"
    local file_path="$2"
    local variable_name="$3"

    local url="https://api.github.com/repos/$repo/contents/$file_path"
    local response=$(curl -s "$url")

    # Check if the response contains an error message
    if [[ $response =~ "message" ]]; then
        echo "Error: Failed to retrieve file contents from GitHub."
        return 1
    fi

    # Extract the content from the response
    local content=$(echo "$response" | tr -d '\n' | jq -r '.content')

    if [[ "$content" == "null" ]]; then
        echo "File '$file_path' not found in the repository."
        return 1
    fi

    # Decode the Base64-encoded content
    local decoded_content=$(echo "$content" | base64 --decode)

    # Extract the variable value from the content
    local variable_value=$(echo "$decoded_content" | grep "$variable_name" | awk -F '=' '{print $2}' | tr -d ' ')

    if [[ -z "$variable_value" ]]; then
        echo "Variable '$variable_name' not found in the file '$file_path'."
        return 1
    fi

    strip_quotes $variable_value
}

strip_quotes() {
    local input="$1"

    # Remove leading and trailing quotes using parameter expansion
    local stripped="${input#\"}"
    stripped="${stripped%\"}"

    echo "$stripped"
}

# Loop through all command line arguments
while [[ $# -gt 0 ]]; do
  arg="$1"

  # Check if the argument starts with a hyphen (flag)
  if [[ "$arg" == -* ]]; then
    # Check if the argument has a value
    if [[ $# -gt 1 && "$2" != -* ]]; then
          if [[ "$arg" == "--script" ]]; then
            script="$2";
            shift 2
        else
            # Add '=' sign between flag and value
            args+=("'$arg'");
            args+=("'$2'");
            shift 2
        fi
    else
      # Add '=True' for flags with no value
      args+=("'$arg'");
      shift
    fi
  else
    # Argument is not a flag, add it as it is
    args+=("'$arg '");
    shift
  fi
done

# Check if script argument was provided
if [[ -z "$script" ]]; then
    echo "The --script argument is required."
    exit 1
fi

branch=$(git branch --show-current) # get current branch.
echo watching branch: $branch
echo pm2 process name: $proc_name

# Get the current version locally.
current_version=$(read_version_value)

# Check if script is already running with pm2
if pm2 status | grep -q $proc_name; then
    echo "The script is already running with pm2. Stopping and restarting..."
    pm2 delete $proc_name
fi

# Run the Python script with the arguments using pm2
echo "Running $script with the following pm2 config:"

# Join the arguments with commas using printf
joined_args=$(printf "%s," "${args[@]}")

# Remove the trailing comma
joined_args=${joined_args%,}

# Create the pm2 config file
echo "module.exports = {
  apps : [{
    name   : '$proc_name',
    script : '$script',
    min_uptime: '5m',
    max_restarts: '5',
    args: [$joined_args]
  }]
}" > $validator_pm2_config

# Print configuration to be used
cat $validator_pm2_config
pm2 start $validator_pm2_config

# Check if the command was successful
if [ $? -ne 0 ]; then
    echo "There was an issue starting the pm2 process."
else
    echo "pm2 process started successfully."
fi

# Check if packages are installed.
check_package_installed "jq"
if [ "$?" -eq 1 ]; then
    while true; do

        # First ensure that this is a git installation
        if [ -d "./.git" ]; then

            # check value on github remotely
            latest_version=$(check_variable_value_on_github "macrocosm-os/folding" "folding/__init__.py" "__version__ ")

            # If the file has been updated
            if version_less_than $current_version $latest_version; then
                echo "latest version $latest_version"
                echo "current version $current_version"
                diff=$(get_version_difference $latest_version $current_version)
                if [ "$diff" -eq 1 ]; then
                    echo "current validator version:" "$current_version" 
                    echo "latest validator version:" "$latest_version" 

                    # Pull latest changes
                    # Failed git pull will return a non-zero output
                    if git pull origin $branch; then
                        # latest_version is newer than current_version, should download and reinstall.
                        echo "New version published. Updating the local copy."

                        # Install latest changes just in case.
                        pip install -e .

                        # # Run the Python script with the arguments using pm2
                        pm2 del auto_run_validator
                        echo "Restarting PM2 process"
                        pm2 restart $proc_name

                        # Update current version:
                        current_version=$(read_version_value)
                        echo ""

                        # Restart autorun script
                        echo "Restarting script..."
                        ./$(basename $0) $old_args && exit
                    else
                        echo "**Will not update**"
                        echo "It appears you have made changes on your local copy. Please stash your changes using git stash."
                    fi
                else
                    # current version is newer than the latest on git. This is likely a local copy, so do nothing. 
                    echo "**Will not update**"
                    echo "The local version is $diff versions behind. Please manually update to the latest version and re-run this script."
                fi
            else
                echo "**Skipping update **"
                echo "$current_version is the same as or more than $latest_version. You are likely running locally."
            fi
        else
            echo "The installation does not appear to be done through Git. Please install from source at https://github.com/macrocosm-os/folding and rerun this script."
        fi
        
        # Wait about 30 minutes
        # This should be plenty of time for validators to catch up
        # and should prevent any rate limitations by GitHub.
        echo "Sleeping for 1800 seconds before checking update..."
        sleep 1800
    done
else
    echo "Missing package 'jq'. Please install it for your system first."
fi