#!/usr/bin/env bash

set -euo pipefail

repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"

readme_path="$repo_root/README.md"

pages_html_path="$repo_root/README.pages.html"

metadata_path="$repo_root/scripts/readme-metadata.tsv"

repo_url_base="https://github.com/boudhayan/Algorithm-Solutions-In-Swift/tree/main"

url_encode() {

local raw="$1"

local length i char

length=${#raw}

for ((i = 0; i < length; i++)); do

char="${raw:i:1}"

case "$char" in

[a-zA-Z0-9.~_/-]) printf '%s' "$char" ;;

*) printf '%%%02X' "'$char" ;;

esac

done

}

trim_whitespace() {

local value="$1"

value="${value#"${value%%[![:space:]]*}"}"

value="${value%"${value##*[![:space:]]}"}"

printf '%s' "$value"

}

escape_table_text() {

printf '%s' "$1" | sed 's/|/\\|/g'

}

html_escape() {

printf '%s' "$1" \

| sed -e 's/&/\&amp;/g' \

-e 's/</\&lt;/g' \

-e 's/>/\&gt;/g' \

-e 's/"/\&quot;/g' \

-e "s/'/\&#39;/g"

}

metadata_lookup() {

local category="$1"

local problem="$2"

local field="$3"

local col

if [[ ! -f "$metadata_path" ]]; then

printf ''

return 0

fi

case "$field" in

difficulty) col=3 ;;

topic) col=4 ;;

problem_url) col=5 ;;

*)

printf ''

return 0

;;

esac

awk -F '\t' -v c="$category" -v p="$problem" -v col="$col" '

$0 ~ /^#/ || NF == 0 { next }

$1 == c && $2 == p {

print $col

found = 1

exit

}

END {

if (!found) {

print ""

}

}

' "$metadata_path"

}

extract_problem_url_from_files() {

local dir="$1"

local url

if command -v rg >/dev/null 2>&1; then

url="$(rg -o --no-filename -m 1 "https?://[^[:space:]\\\"'<>)]+" "$dir" 2>/dev/null | head -n 1 || true)"

else

url="$(grep -RhoE "https?://[^[:space:]\\\"'<>)]+" "$dir" 2>/dev/null | head -n 1 || true)"

fi

url="$(printf '%s' "$url" | sed 's/[.,;:]*$//')"

printf '%s' "$url"

}

default_problem_link() {

local category="$1"

local problem="$2"

local encoded_problem

encoded_problem="$(url_encode "$problem")"

case "$category" in

LeetCode)

printf 'https://leetcode.com/problemset/all/?search=%s' "$encoded_problem"

;;

HackerRank)

printf 'https://www.hackerrank.com/search?search=%s' "$encoded_problem"

;;

GeekForGeeks)

printf 'https://www.geeksforgeeks.org/?s=%s' "$encoded_problem"

;;

Pramp)

printf 'https://www.pramp.com/#/?q=%s' "$encoded_problem"

;;

*)

printf ''

;;

esac

}

infer_topic() {

local problem="$1"

local lowered

lowered="$(printf '%s' "$problem" | tr '[:upper:]' '[:lower:]')"

case "$lowered" in

*"linked list"*|*"list cycle"*)

printf 'Linked List'

;;

*"tree"*|*"bst"*|*"binary search tree"*)

printf 'Tree'

;;

*"graph"*|*"bfs"*|*"dfs"*|*"topological"*)

printf 'Graph'

;;

*"matrix"*|*"grid"*|*"island"*|*"spiral"*)

printf 'Matrix'

;;

*"string"*|*"palindrome"*|*"anagram"*|*"substring"*|*"word"*)

printf 'String'

;;

*"sort"*)

printf 'Sorting'

;;

*"search"*)

printf 'Searching'

;;

*"array"*|*"subarray"*|*"sum"*|*"two number"*|*"three number"*)

printf 'Array'

;;

*"stack"*|*"queue"*)

printf 'Stack / Queue'

;;

*)

printf '_'

;;

esac

}

generate_table() {

local category="$1"

local index=1

local dir problem_raw problem_name encoded_path solution_link

local metadata_problem_url file_problem_url problem_url

local difficulty topic problem_link_cell solution_link_cell

printf '| Serial No. | Problem | Problem Link | Solution | Difficulty | Topic/Pattern | Notes |\n'

printf '|---|---|---|---|---|---|---|\n'

while IFS= read -r dir; do

problem_raw="$(basename "$dir")"

problem_raw="$(trim_whitespace "$problem_raw")"

problem_name="$(escape_table_text "$problem_raw")"

encoded_path="$(url_encode "${dir#$repo_root/}")"

solution_link="${repo_url_base}/${encoded_path}"

solution_link_cell="[Solution](${solution_link})"

metadata_problem_url="$(trim_whitespace "$(metadata_lookup "$category" "$problem_raw" "problem_url")")"

file_problem_url="$(extract_problem_url_from_files "$dir")"

if [[ -n "$metadata_problem_url" ]]; then

problem_url="$metadata_problem_url"

elif [[ -n "$file_problem_url" ]]; then

problem_url="$file_problem_url"

else

problem_url="$(default_problem_link "$category" "$problem_raw")"

fi

if [[ -n "$problem_url" ]]; then

problem_link_cell="[Problem](${problem_url})"

else

problem_link_cell="_"

fi

difficulty="$(trim_whitespace "$(metadata_lookup "$category" "$problem_raw" "difficulty")")"

if [[ -z "$difficulty" ]]; then

difficulty="_"

fi

difficulty="$(escape_table_text "$difficulty")"

topic="$(trim_whitespace "$(metadata_lookup "$category" "$problem_raw" "topic")")"

if [[ -z "$topic" ]]; then

topic="$(infer_topic "$problem_raw")"

fi

topic="$(escape_table_text "$topic")"

printf '|%d|%s|%s|%s|%s|%s|_|\n' \

"$index" "$problem_name" "$problem_link_cell" "$solution_link_cell" "$difficulty" "$topic"

index=$((index + 1))

done < <(

find "$repo_root/$category" -mindepth 1 -maxdepth 1 -type d | LC_ALL=C sort

)

}

category_repo_url() {

local category="$1"

case "$category" in

HackerRank)

printf 'https://github.com/boudhayan/Algorithm-Solutions-In-Swift/tree/main/HackerRank/'

;;

LeetCode)

printf 'https://github.com/boudhayan/Algorithm-Solutions-In-Swift/tree/main/LeetCode/'

;;

AlgoExpert)

printf 'https://github.com/boudhayan/Algorithm-Solutions-In-Swift/tree/main/AlgoExpert/'

;;

GeekForGeeks)

printf 'https://github.com/boudhayan/Algorithm-Solutions-In-Swift/tree/main/GeekForGeeks/'

;;

Pramp)

printf 'https://github.com/boudhayan/Algorithm-Solutions-In-Swift/tree/main/Pramp/'

;;

*)

printf '%s' "$repo_url_base"

;;

esac

}

generate_solution_cards_html() {

local category section_url platform_slug index=1

local dir problem_raw problem_name encoded_path solution_link

local metadata_problem_url file_problem_url problem_url

local difficulty topic search_blob problem_url_attr solution_url_attr

for category in HackerRank LeetCode AlgoExpert GeekForGeeks Pramp; do

section_url="$(category_repo_url "$category")"

platform_slug="$(printf '%s' "$category" | tr '[:upper:]' '[:lower:]')"

index=1

while IFS= read -r dir; do

problem_raw="$(basename "$dir")"

problem_raw="$(trim_whitespace "$problem_raw")"

problem_name="$(html_escape "$problem_raw")"

encoded_path="$(url_encode "${dir#$repo_root/}")"

solution_link="${repo_url_base}/${encoded_path}"

solution_url_attr="$(html_escape "$solution_link")"

metadata_problem_url="$(trim_whitespace "$(metadata_lookup "$category" "$problem_raw" "problem_url")")"

file_problem_url="$(extract_problem_url_from_files "$dir")"

if [[ -n "$metadata_problem_url" ]]; then

problem_url="$metadata_problem_url"

elif [[ -n "$file_problem_url" ]]; then

problem_url="$file_problem_url"

else

problem_url="$(default_problem_link "$category" "$problem_raw")"

fi

difficulty="$(trim_whitespace "$(metadata_lookup "$category" "$problem_raw" "difficulty")")"

if [[ -z "$difficulty" || "$difficulty" == "_" ]]; then

difficulty="Unknown"

fi

topic="$(trim_whitespace "$(metadata_lookup "$category" "$problem_raw" "topic")")"

if [[ -z "$topic" ]]; then

topic="$(infer_topic "$problem_raw")"

fi

if [[ "$topic" == "_" ]]; then

topic="General"

fi

search_blob="$(printf '%s %s %s %s' "$problem_raw" "$category" "$difficulty" "$topic" | tr '[:upper:]' '[:lower:]')"

printf '<article class="solution-card" data-platform="%s" data-search="%s">\n' \

"$(html_escape "$platform_slug")" "$(html_escape "$search_blob")"

printf ' <div class="solution-card-top">\n'

printf ' <a class="platform-pill platform-%s" href="%s">%s</a>\n' \

"$(html_escape "$platform_slug")" "$(html_escape "$section_url")" "$(html_escape "$category")"

printf ' <span class="serial-pill">#%d</span>\n' "$index"

printf ' </div>\n'

printf ' <h3>%s</h3>\n' "$problem_name"

printf ' <p class="solution-card-meta"><span>%s</span><span>%s</span></p>\n' \

"$(html_escape "$difficulty")" "$(html_escape "$topic")"

printf ' <div class="solution-card-actions">\n'

if [[ -n "$problem_url" ]]; then

problem_url_attr="$(html_escape "$problem_url")"

printf ' <a class="card-link" href="%s">Problem</a>\n' "$problem_url_attr"

else

printf ' <span class="card-link card-link-muted">Problem N/A</span>\n'

fi

printf ' <a class="card-link card-link-primary" href="%s">Solution</a>\n' "$solution_url_attr"

printf ' </div>\n'

printf '</article>\n'

index=$((index + 1))

done < <(

find "$repo_root/$category" -mindepth 1 -maxdepth 1 -type d | LC_ALL=C sort

)

done

}

generate_pages_html() {

cat <<'EOF'

<h1>Algorithms Solutions in Swift</h1>

<p>This repository contains Swift solutions from AlgoExpert, LeetCode, HackerRank, GeekForGeeks, and Pramp.</p>

<p>Suggestions and contributions are welcome.</p>

<h2>How to Use</h2>

<ul>

<li>Use search and platform filters to quickly find a problem.</li>

<li>Open <strong>Problem</strong> for the original prompt and <strong>Solution</strong> for this repository implementation.</li>

<li>Update <code>Difficulty</code>, <code>Topic/Pattern</code>, or <code>Problem Link</code> overrides in <code>scripts/readme-metadata.tsv</code>.</li>

</ul>

<section class="solutions-toolbar" aria-label="Solution filters">

<div class="solutions-search-wrap">

<label for="solution-search">Search solutions</label>

<input id="solution-search" type="search" placeholder="Type problem, topic, or platform..." autocomplete="off" />

</div>

<div class="platform-filters" role="group" aria-label="Platform filters">

<button class="platform-filter is-active" type="button" data-platform-filter="all">All</button>

<button class="platform-filter" type="button" data-platform-filter="hackerrank">HackerRank</button>

<button class="platform-filter" type="button" data-platform-filter="leetcode">LeetCode</button>

<button class="platform-filter" type="button" data-platform-filter="algoexpert">AlgoExpert</button>

<button class="platform-filter" type="button" data-platform-filter="geeksforgeeks">GeekForGeeks</button>

<button class="platform-filter" type="button" data-platform-filter="pramp">Pramp</button>

</div>

<p id="results-count" class="results-count"></p>

</section>

<section id="solution-cards" class="solution-card-grid">

EOF

generate_solution_cards_html

cat <<'EOF'

</section>

<script>

(() => {

const searchInput = document.getElementById("solution-search");

const cards = Array.from(document.querySelectorAll(".solution-card"));

const resultCount = document.getElementById("results-count");

const platformButtons = Array.from(document.querySelectorAll("[data-platform-filter]"));

let activePlatform = "all";

if (!searchInput || cards.length === 0 || !resultCount) {

return;

}

const renderCount = (visible, total) => {

resultCount.textContent = `Showing ${visible} of ${total} solutions`;

};

const applyFilters = () => {

const query = searchInput.value.trim().toLowerCase();

let visibleCount = 0;

cards.forEach((card) => {

const cardPlatform = card.dataset.platform || "";

const cardSearch = card.dataset.search || "";

const matchesPlatform = activePlatform === "all" || cardPlatform === activePlatform;

const matchesQuery = query.length === 0 || cardSearch.includes(query);

const isVisible = matchesPlatform && matchesQuery;

card.hidden = !isVisible;

if (isVisible) {

visibleCount += 1;

}

});

renderCount(visibleCount, cards.length);

};

platformButtons.forEach((button) => {

button.addEventListener("click", () => {

activePlatform = button.dataset.platformFilter || "all";

platformButtons.forEach((otherButton) => {

otherButton.classList.toggle("is-active", otherButton === button);

});

applyFilters();

});

});

searchInput.addEventListener("input", applyFilters);

renderCount(cards.length, cards.length);

})();

</script>

EOF

}

replace_section() {

local section="$1"

local rows_file="$2"

local temp_file

temp_file="$(mktemp)"

awk -v section="$section" -v rows_file="$rows_file" '

BEGIN {

start_tag = "<!-- AUTO:START:" section " -->"

end_tag = "<!-- AUTO:END:" section " -->"

in_block = 0

found_start = 0

found_end = 0

}

$0 == start_tag {

print

while ((getline row < rows_file) > 0) {

print row

}

close(rows_file)

in_block = 1

found_start = 1

next

}

$0 == end_tag {

in_block = 0

found_end = 1

print

next

}

!in_block {

print

}

END {

if (!found_start || !found_end) {

exit 2

}

}

' "$readme_path" > "$temp_file" || {

rm -f "$temp_file"

echo "Failed to update section $section in README.md" >&2

exit 1

}

mv "$temp_file" "$readme_path"

}

hackerrank_table="$(mktemp)"

leetcode_table="$(mktemp)"

algoexpert_table="$(mktemp)"

geeksforgeeks_table="$(mktemp)"

pramp_table="$(mktemp)"

trap 'rm -f "$hackerrank_table" "$leetcode_table" "$algoexpert_table" "$geeksforgeeks_table" "$pramp_table"' EXIT

generate_table "HackerRank" > "$hackerrank_table"

generate_table "LeetCode" > "$leetcode_table"

generate_table "AlgoExpert" > "$algoexpert_table"

generate_table "GeekForGeeks" > "$geeksforgeeks_table"

generate_table "Pramp" > "$pramp_table"

replace_section "HACKERRANK" "$hackerrank_table"

replace_section "LEETCODE" "$leetcode_table"

replace_section "ALGOEXPERT" "$algoexpert_table"

replace_section "GEEKSFORGEEKS" "$geeksforgeeks_table"

replace_section "PRAMP" "$pramp_table"

# Pages uses this HTML copy for stable table rendering.

generate_pages_html > "$pages_html_path"

echo "README.md updated from directory structure."