feat: Implement main functionality

Author: WhiteHyun

scripts/leetcode.bash

@@ -0,0 +1,53 @@
+#!/usr/bin/env bash
+
+source scripts/common.bash
+source scripts/leetcode_helper.bash
+
+function main() {
+  load_env_vars
+
+  # Check if required commands are installed
+  check_command "jq"
+  check_command "bash"
+
+  # Check if the problem title-slug or URL is provided
+  if [ "$#" -eq 1 ]; then
+    input="$1"
+    if [[ "$input" == *"https://leetcode.com/problems/"* ]]; then
+      # If the input is a LeetCode URL
+      problem_slug=$(extract_problem_name "$input")
+    else
+      # If the input is already a title-slug
+      problem_slug="$input"
+    fi
+  else
+    echo "Please provide the LeetCode problem title-slug or URL."
+    exit 1
+  fi
+
+  echo "Problem Slug: $problem_slug"
+
+  # GraphQL query to fetch problem details
+  query=$(make_query "$problem_slug")
+
+  echo "Requesting problem details from LeetCode GraphQL API..."
+
+  # Send a POST request to the LeetCode GraphQL API
+  response=$(request "$query")
+
+  # Check if the response contains valid data
+  if ! echo -E "$response" | jq -e '.data.question' >/dev/null 2>&1; then
+    echo -E "$response"
+    echo "Failed to receive a valid response from the LeetCode API. Exiting the script."
+    exit 1
+  fi
+
+  echo "Received problem details response from LeetCode."
+
+  # Create the file
+
+  create_file "$response"
+}
+
+# Call the main function
+main "$@"