#include "repositories/MigrationRunner.h"

#include <drogon/drogon.h>

#include <algorithm>
#include <cctype>
#include <filesystem>
#include <fstream>
#include <sstream>
#include <string>
#include <vector>

namespace visione::repositories
{
namespace
{
std::string trim(std::string value)
{
    auto notSpace = [](unsigned char ch) { return !std::isspace(ch); };
    value.erase(value.begin(),
                std::find_if(value.begin(), value.end(), notSpace));
    value.erase(std::find_if(value.rbegin(), value.rend(), notSpace).base(),
                value.end());
    return value;
}

std::vector<std::string> splitStatements(const std::string &sql)
{
    std::vector<std::string> statements;
    std::string current;
    bool inSingleQuote = false;
    bool inDoubleQuote = false;

    for (char ch : sql)
    {
        if (ch == '\'' && !inDoubleQuote)
        {
            inSingleQuote = !inSingleQuote;
        }
        else if (ch == '"' && !inSingleQuote)
        {
            inDoubleQuote = !inDoubleQuote;
        }

        if (ch == ';' && !inSingleQuote && !inDoubleQuote)
        {
            auto statement = trim(current);
            if (!statement.empty())
            {
                statements.push_back(std::move(statement));
            }
            current.clear();
            continue;
        }

        current.push_back(ch);
    }

    auto statement = trim(current);
    if (!statement.empty())
    {
        statements.push_back(std::move(statement));
    }
    return statements;
}
}  // namespace

void MigrationRunner::run(const std::string &directory)
{
    namespace fs = std::filesystem;

    std::vector<fs::path> files;
    if (!fs::exists(directory))
    {
        LOG_WARN << "Migration directory not found: " << directory;
        return;
    }

    for (const auto &entry : fs::directory_iterator(directory))
    {
        if (entry.is_regular_file() && entry.path().extension() == ".sql")
        {
            files.push_back(entry.path());
        }
    }
    std::sort(files.begin(), files.end());

    auto db = drogon::app().getDbClient();
    for (const auto &file : files)
    {
        std::ifstream input(file);
        std::stringstream buffer;
        buffer << input.rdbuf();

        for (const auto &statement : splitStatements(buffer.str()))
        {
            db->execSqlSync(statement);
        }
        LOG_INFO << "Applied migration " << file.string();
    }
}
}  // namespace visione::repositories