#!/bin/bash

id=$1

echo "$id" | grep -q "^[1-9][0-9]\{,4\}$" || {
    echo "Err: no valid problem ID provided." >&2
    exit 1
}

parent=$((id / 100))
pdir="solutions/${parent}/q${id}"
sol_file="${pdir}/solution.go"

if [ -f "$sol_file" ]; then
    exit 0
fi

title_slug=$(jq -r "select(.frontendId == $id) | .titleSlug" ./problemset.jsonl)
[ -n "$title_slug" ] || {
    echo "Err: problem $id not found in the problem set." >&2
    exit 1
}
problem_url="https://leetcode.com/problems/$title_slug/"

echo -e "Creating template for problem \033[32m${id}: $title_slug\033[0m" >&2
mkdir -pv "$pdir"
echo "// Package q$id implements a solution for $problem_url" > "$sol_file"
echo -e "package q$id\n" >> "$sol_file"
echo "Created: $sol_file"

echo "Fetching code snippet for Go ..."
curl -sSLf "${problem_url}description/" \
    -H 'accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8' \
    -H 'accept-language: en-US,en;q=0.5' \
    -H 'cache-control: max-age=0' \
    -H 'priority: u=0, i' \
    -H 'sec-ch-ua: "Not:A-Brand";v="99", "Brave";v="145", "Chromium";v="145"' \
    -H 'sec-ch-ua-mobile: ?0' \
    -H 'sec-ch-ua-platform: "Linux"' \
    -H 'sec-fetch-dest: document' \
    -H 'sec-fetch-mode: navigate' \
    -H 'sec-fetch-site: same-origin' \
    -H 'sec-fetch-user: ?1' \
    -H 'sec-gpc: 1' \
    -H 'upgrade-insecure-requests: 1' \
    -H 'user-agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36' \
    | grep -o 'NEXT_DATA[^>]*>.*' \
    | sed 's/^[^>]*>//;s/<\/script.*//' \
    | jq -r '[ .props.pageProps.dehydratedState.queries[].state.data.question.codeSnippets | select( . != null) | .[] | select(.langSlug == "golang") ][0].code' \
        >> "$sol_file"

echo "Done."