/*
MIT License

Copyright (c) 2026 Poul Sander

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

*/

#include "util.h"

#include <algorithm>
#include <array>
#include <cstdio>
#include <cstdlib>

namespace util {

namespace {
constexpr int MIN_OID_LEN = 4;
constexpr int MAX_OID_LEN = 40;
} // namespace

bool is_hex_oid(const std::string &s) {
    if (s.length() < MIN_OID_LEN || s.length() > MAX_OID_LEN)
        return false;
    for (char c : s) {
        const bool is_digit = c >= '0' && c <= '9';
        const bool is_lower_hex = c >= 'a' && c <= 'f';
        if (!is_digit && !is_lower_hex)
            return false;
    }
    return true;
}

std::string human_size(uint64_t bytes) {
    constexpr uint64_t unit = 1024;
    const std::array<const char *, 5> suffixes{"B", "KiB", "MiB", "GiB", "TiB"};
    if (bytes < unit)
        return std::to_string(bytes) + " B";

    double value = static_cast<double>(bytes);
    size_t i = 0;
    while (value >= unit && i + 1 < suffixes.size()) {
        value /= unit;
        ++i;
    }
    std::array<char, 32> buf{};
    std::snprintf(buf.data(), buf.size(), "%.1f %s", value, suffixes[i]);
    return std::string(buf.data());
}

std::string format_time(std::time_t t) {
    std::tm tm{};
    gmtime_r(&t, &tm);
    std::array<char, 32> buf{};
    std::strftime(buf.data(), buf.size(), "%Y-%m-%d %H:%M", &tm);
    return std::string(buf.data());
}

std::string basename(const std::string &path) {
    const size_t pos = path.find_last_of('/');
    if (pos == std::string::npos)
        return path;
    return path.substr(pos + 1);
}

std::string parent_path(const std::string &path) {
    const size_t pos = path.find_last_of('/');
    if (pos == std::string::npos)
        return "";
    return path.substr(0, pos);
}

std::string trim_slashes(const std::string &path) {
    size_t start = 0;
    size_t end = path.length();
    while (start < end && path[start] == '/')
        ++start;
    while (end > start && path[end - 1] == '/')
        --end;
    return path.substr(start, end - start);
}

std::string sanitize_filename(const std::string &name) {
    std::string out = name;
    for (char &c : out) {
        const bool is_digit = c >= '0' && c <= '9';
        const bool is_upper = c >= 'A' && c <= 'Z';
        const bool is_lower = c >= 'a' && c <= 'z';
        const bool is_safe_punct = c == '.' || c == '_' || c == '-';
        if (!is_digit && !is_upper && !is_lower && !is_safe_punct)
            c = '_';
    }
    return out;
}

bool is_markdown_path(const std::string &path) {
    const size_t dot = path.find_last_of('.');
    if (dot == std::string::npos)
        return false;
    std::string ext = path.substr(dot + 1);
    std::transform(ext.begin(), ext.end(), ext.begin(), ::tolower);
    return ext == "md" || ext == "markdown";
}

std::string image_mime_type(const std::string &path) {
    const size_t dot = path.find_last_of('.');
    if (dot == std::string::npos)
        return "";
    std::string ext = path.substr(dot + 1);
    std::transform(ext.begin(), ext.end(), ext.begin(), ::tolower);
    if (ext == "png")
        return "image/png";
    if (ext == "jpg" || ext == "jpeg")
        return "image/jpeg";
    if (ext == "gif")
        return "image/gif";
    if (ext == "webp")
        return "image/webp";
    if (ext == "svg")
        return "image/svg+xml";
    if (ext == "bmp")
        return "image/bmp";
    if (ext == "ico")
        return "image/x-icon";
    if (ext == "avif")
        return "image/avif";
    return "";
}

namespace {

// Splits a remote URL into host and path ("owner/repo[.git]"). Returns false
// when the URL has no recognisable host/path split.
bool split_remote(const std::string &url, std::string &host, std::string &path) {
    const std::string scheme_sep = "://";
    const size_t scheme = url.find(scheme_sep);
    if (scheme != std::string::npos) {
        // scheme://[user@]host[:port]/owner/repo
        std::string rest = url.substr(scheme + scheme_sep.length());
        const size_t at = rest.find('@');
        if (at != std::string::npos)
            rest = rest.substr(at + 1);
        const size_t slash = rest.find('/');
        if (slash == std::string::npos)
            return false;
        host = rest.substr(0, slash);
        path = rest.substr(slash + 1);
        const size_t port = host.find(':');
        if (port != std::string::npos)
            host = host.substr(0, port);
        return true;
    }
    // scp-like: [user@]host:owner/repo
    const size_t colon = url.find(':');
    if (colon == std::string::npos)
        return false;
    std::string host_part = url.substr(0, colon);
    path = url.substr(colon + 1);
    const size_t at = host_part.find('@');
    host = at == std::string::npos ? host_part : host_part.substr(at + 1);
    return true;
}

bool is_github_host(std::string host, const std::vector<std::string> &enterprise_hosts) {
    std::transform(host.begin(), host.end(), host.begin(), ::tolower);
    if (host == "github.com")
        return true;
    for (const std::string &configured : enterprise_hosts) {
        std::string h = configured;
        std::transform(h.begin(), h.end(), h.begin(), ::tolower);
        if (host == h)
            return true;
    }
    return false;
}

} // namespace

GitHubClone github_clone_urls(const std::string &remote_url,
                              const std::vector<std::string> &enterprise_hosts) {
    GitHubClone result;
    std::string host;
    std::string path;
    if (!split_remote(remote_url, host, path))
        return result;
    if (!is_github_host(host, enterprise_hosts))
        return result;

    while (path.length() > 0 && path.front() == '/')
        path.erase(path.begin());
    while (path.length() > 0 && path.back() == '/')
        path.pop_back();
    const std::string git_suffix = ".git";
    if (path.length() >= git_suffix.length() &&
        path.compare(path.length() - git_suffix.length(), git_suffix.length(),
                     git_suffix) == 0)
        path = path.substr(0, path.length() - git_suffix.length());
    if (path.empty())
        return result;

    result.ssh = "git@" + host + ":" + path + ".git";
    result.https = "https://" + host + "/" + path + ".git";
    return result;
}

bool show_emails() {
    static const bool value = [] {
        const char *flag = std::getenv("SHOW_EMAILS");
        return flag && std::string(flag) == "1";
    }();
    return value;
}

} // namespace util