#!/bin/bash

# This script connects to CentralDB, lists available activities, and allows the user to download a selected activity file.

# --- Configuration ---
CENTRAL_DB_URL="http://localhost:8000" # Adjust if your CentralDB is running on a different host/port

# --- Function to display error and exit ---
function error_exit {
  echo "Error: $1" >&2
  exit 1
}

# --- Get list of activities ---
echo "Fetching list of activities from CentralDB..."
ACTIVITIES_JSON=$(curl -s "${CENTRAL_DB_URL}/activities")

if [ -z "${ACTIVITIES_JSON}" ]; then
  error_exit "No response received from CentralDB. Is the CentralDB service running?"
fi

# Check if jq is installed
if ! command -v jq &> /dev/null; then
    error_exit "jq is not installed. Please install jq to parse JSON output (e.g., sudo apt-get install jq or brew install jq)."
fi

# Parse JSON and display activities
ACTIVITIES_COUNT=$(echo "${ACTIVITIES_JSON}" | jq '. | length')

if [ "${ACTIVITIES_COUNT}" -eq 0 ]; then
  echo "No activities found in CentralDB."
  exit 0
fi

echo "Available Activities:"
echo "${ACTIVITIES_JSON}" | jq -c '.[] | {id: .id, file_path: .file_path, filename: .activity_metadata.filename}' | \
  nl -w 2 -s ') ' | while read -r line; do
    ACTIVITY_ID=$(echo "$line" | sed -E 's/^[[:space:]]*[0-9]+) {id:([0-9]+),.*$/\1/')
    FILENAME=$(echo "$line" | sed -E 's/^[[:space:]]*[0-9]+) {id:[0-9]+, file_path:".*", filename:"([^"]+)".*$/\1/')
    echo "$line (ID: ${ACTIVITY_ID}, Filename: ${FILENAME})"
  done

# --- Prompt user for selection ---
read -p "Enter the number of the activity to download: " SELECTION_NUMBER

if ! [[ "${SELECTION_NUMBER}" =~ ^[0-9]+$ ]]; then
  error_exit "Invalid input. Please enter a number."
fi

if [ "${SELECTION_NUMBER}" -lt 1 ] || [ "${SELECTION_NUMBER}" -gt "${ACTIVITIES_COUNT}" ]; then
  error_exit "Invalid selection. Please enter a number between 1 and ${ACTIVITIES_COUNT}."
fi

# Get selected activity details
SELECTED_ACTIVITY=$(echo "${ACTIVITIES_JSON}" | jq ".[$((${SELECTION_NUMBER} - 1))]" -c)
SELECTED_ACTIVITY_ID=$(echo "${SELECTED_ACTIVITY}" | jq -r '.id')
SELECTED_FILENAME=$(echo "${SELECTED_ACTIVITY}" | jq -r '.activity_metadata.filename')

if [ -z "${SELECTED_ACTIVITY_ID}" ] || [ -z "${SELECTED_FILENAME}" ]; then
  error_exit "Could not retrieve details for selected activity."
fi

# --- Download the selected activity file ---
echo "Downloading activity ID: ${SELECTED_ACTIVITY_ID} (Filename: ${SELECTED_FILENAME})..."
DOWNLOAD_URL="${CENTRAL_DB_URL}/activities/${SELECTED_ACTIVITY_ID}/file"

# Use curl to download the file and save it with the correct filename
curl -s -o "${SELECTED_FILENAME}" "${DOWNLOAD_URL}"

if [ $? -eq 0 ]; then
  echo "Successfully downloaded ${SELECTED_FILENAME}"
else
  error_exit "Failed to download activity file."
fi