#include <smartbotic/database/client.hpp>
#include <nlohmann/json.hpp>

#include <iostream>
#include <sstream>
#include <string>
#include <vector>

using json = nlohmann::json;

namespace {

struct Args {
    std::string address = "localhost:9004";
    std::string command;
    std::vector<std::string> params;
};

// ANSI colors
constexpr auto C_RESET = "\033[0m";
constexpr auto C_BOLD  = "\033[1m";
constexpr auto C_DIM   = "\033[2m";
constexpr auto C_CYAN  = "\033[36m";
constexpr auto C_GREEN = "\033[32m";
constexpr auto C_RED   = "\033[31m";
constexpr auto C_YELLOW = "\033[33m";

void printJson(const json& j) {
    std::cout << j.dump(2) << "\n";
}

void printError(const std::string& msg) {
    std::cerr << C_RED << "error: " << C_RESET << msg << "\n";
}

void printUsage() {
    std::cout << C_BOLD << "smartbotic-db-cli" << C_RESET << " — admin tool for smartbotic-database\n\n"
              << C_BOLD << "Usage:" << C_RESET << "\n"
              << "  smartbotic-db-cli [--address HOST:PORT] <command> [args...]\n"
              << "  smartbotic-db-cli [--address HOST:PORT]   " << C_DIM << "# interactive mode" << C_RESET << "\n\n"
              << C_BOLD << "Commands:" << C_RESET << "\n"
              << "  " << C_CYAN << "collections" << C_RESET << "                          List all collections\n"
              << "  " << C_CYAN << "info" << C_RESET << " <collection>                    Collection info\n"
              << "  " << C_CYAN << "find" << C_RESET << " <collection>                    List documents\n"
              << "  " << C_CYAN << "get" << C_RESET << " <collection> <id>                Get a document\n"
              << "  " << C_CYAN << "upsert" << C_RESET << " <collection> <id> '<json>'    Insert or update\n"
              << "  " << C_CYAN << "remove" << C_RESET << " <collection> <id>             Delete a document\n"
              << "  " << C_CYAN << "count" << C_RESET << " <collection>                   Count documents\n"
              << "  " << C_CYAN << "lock" << C_RESET << "                                 Lock database (read-only)\n"
              << "  " << C_CYAN << "unlock" << C_RESET << "                               Unlock database (accept writes)\n"
              << "  " << C_CYAN << "status" << C_RESET << "                               Show read-only + recovery status\n"
              << "  " << C_CYAN << "help" << C_RESET << "                                 Show this help\n\n"
              << C_BOLD << "Options:" << C_RESET << "\n"
              << "  --address HOST:PORT    Database address (default: localhost:9004)\n";
}

bool execCommand(smartbotic::database::Client& client,
                 const std::string& cmd, const std::vector<std::string>& params) {
    try {
        if (cmd == "collections") {
            auto collections = client.listCollections();
            std::cout << C_BOLD << "Collections:" << C_RESET << "\n";
            for (const auto& c : collections) {
                auto info = client.getCollectionInfo(c);
                int64_t count = 0;
                if (info) count = info->documentCount;
                std::cout << "  " << C_CYAN << c << C_RESET
                          << C_DIM << " (" << count << " docs)" << C_RESET << "\n";
            }
            return true;
        }

        if (cmd == "info") {
            if (params.empty()) { printError("usage: info <collection>"); return false; }
            auto info = client.getCollectionInfo(params[0]);
            if (!info) { printError("collection not found: " + params[0]); return false; }
            std::cout << C_BOLD << params[0] << C_RESET << ":\n"
                      << "  documents: " << info->documentCount << "\n"
                      << "  size: " << info->sizeBytes << " bytes\n"
                      << "  encrypted: " << (info->encrypted ? "yes" : "no") << "\n"
                      << "  max_versions: " << info->maxVersions << "\n";
            if (info->defaultTtlSeconds > 0)
                std::cout << "  ttl: " << info->defaultTtlSeconds << "s\n";
            return true;
        }

        if (cmd == "find") {
            if (params.empty()) { printError("usage: find <collection> [--limit N] [--exists FIELD]"); return false; }
            smartbotic::database::Client::QueryOptions opts;
            opts.limit = 100;
            for (size_t i = 1; i < params.size(); ++i) {
                if (params[i] == "--limit" && i + 1 < params.size()) {
                    opts.limit = static_cast<uint32_t>(std::stoul(params[++i]));
                } else if (params[i] == "--exists" && i + 1 < params.size()) {
                    opts.filters.emplace_back(params[++i], smartbotic::database::Client::FilterOp::EXISTS, true);
                }
            }
            auto docs = client.find(params[0], opts);
            std::cout << C_DIM << "(" << docs.size() << " documents)" << C_RESET << "\n";
            for (const auto& doc : docs) {
                auto id = doc.value("_id", "");
                // Print compact summary line
                std::cout << C_GREEN << id << C_RESET;
                // Show a few key fields
                for (const auto& [k, v] : doc.items()) {
                    if (k == "_id" || k == "_created_at" || k == "_updated_at") continue;
                    auto val = v.dump();
                    if (val.size() > 60) val = val.substr(0, 57) + "...";
                    std::cout << " " << C_DIM << k << "=" << C_RESET << val;
                    // Limit to 3 fields per line
                    static int field_count = 0;
                    if (++field_count >= 3) { field_count = 0; break; }
                }
                std::cout << "\n";
            }
            return true;
        }

        if (cmd == "get") {
            if (params.size() < 2) { printError("usage: get <collection> <id>"); return false; }
            auto doc = client.get(params[0], params[1]);
            if (!doc) { printError("not found: " + params[0] + "/" + params[1]); return false; }
            printJson(*doc);
            return true;
        }

        if (cmd == "upsert") {
            if (params.size() < 3) { printError("usage: upsert <collection> <id> '<json>'"); return false; }
            auto data = json::parse(params[2], nullptr, false);
            if (!data.is_object()) { printError("invalid JSON: " + params[2]); return false; }
            client.upsert(params[0], data, params[1]);
            std::cout << C_GREEN << "ok" << C_RESET << " " << params[0] << "/" << params[1] << "\n";
            return true;
        }

        if (cmd == "remove" || cmd == "delete") {
            if (params.size() < 2) { printError("usage: remove <collection> <id>"); return false; }
            client.remove(params[0], params[1]);
            std::cout << C_GREEN << "ok" << C_RESET << " removed " << params[0] << "/" << params[1] << "\n";
            return true;
        }

        if (cmd == "count") {
            if (params.empty()) { printError("usage: count <collection>"); return false; }
            auto info = client.getCollectionInfo(params[0]);
            if (!info) { printError("collection not found: " + params[0]); return false; }
            std::cout << info->documentCount << "\n";
            return true;
        }

        if (cmd == "lock") {
            if (client.setReadOnly(true)) {
                std::cout << C_GREEN << "ok" << C_RESET << " Database locked (read-only)\n";
                return true;
            }
            printError("failed to lock database");
            return false;
        }

        if (cmd == "unlock") {
            if (client.setReadOnly(false)) {
                std::cout << C_GREEN << "ok" << C_RESET << " Database unlocked (writes accepted)\n";
                return true;
            }
            printError("failed to unlock database");
            return false;
        }

        if (cmd == "status") {
            auto s = client.getReadOnlyStatus();
            std::cout << "Read-only:          " << (s.readOnly ? (std::string(C_RED) + "YES" + C_RESET) : "no") << "\n";
            if (s.readOnly) {
                std::cout << "Reason:             " << s.reason << "\n";
            }
            std::cout << "Recovery outcome:   " << s.recoveryOutcome << "\n";
            if (!s.expectedSnapshot.empty()) {
                std::cout << "Expected snapshot:  " << s.expectedSnapshot << "\n";
            }
            if (!s.snapshotUsed.empty()) {
                std::cout << "Snapshot used:      " << s.snapshotUsed << "\n";
            }
            if (!s.failureReason.empty()) {
                std::cout << "Failure reason:     " << s.failureReason << "\n";
            }
            std::cout << "WAL replayed:       " << s.walEntriesReplayed << " entries\n";
            std::cout << "Snapshots tried:    " << s.snapshotsAttempted << "\n";
            return true;
        }

        if (cmd == "help" || cmd == "?") {
            printUsage();
            return true;
        }

        printError("unknown command: " + cmd + " (try 'help')");
        return false;

    } catch (const std::exception& e) {
        printError(e.what());
        return false;
    }
}

// Tokenize a line, respecting single/double quotes and JSON braces
std::vector<std::string> tokenize(const std::string& line) {
    std::vector<std::string> tokens;
    std::string current;
    int brace_depth = 0;
    char in_quote = 0;

    for (size_t i = 0; i < line.size(); ++i) {
        char c = line[i];

        if (in_quote) {
            current += c;
            if (c == in_quote && (i == 0 || line[i-1] != '\\')) {
                in_quote = 0;
                // Strip surrounding quotes for simple string tokens
                if (brace_depth == 0 && current.size() >= 2
                    && (current.front() == '\'' || current.front() == '"')
                    && current.front() == current.back()) {
                    current = current.substr(1, current.size() - 2);
                }
            }
            continue;
        }

        if (c == '\'' || c == '"') {
            in_quote = c;
            current += c;
            continue;
        }

        if (c == '{') { brace_depth++; current += c; continue; }
        if (c == '}') {
            brace_depth--;
            current += c;
            if (brace_depth <= 0) {
                brace_depth = 0;
                tokens.push_back(current);
                current.clear();
            }
            continue;
        }

        if (brace_depth > 0) { current += c; continue; }

        if (c == ' ' || c == '\t') {
            if (!current.empty()) {
                tokens.push_back(current);
                current.clear();
            }
            continue;
        }

        current += c;
    }
    if (!current.empty()) tokens.push_back(current);
    return tokens;
}

} // anonymous namespace

int main(int argc, char* argv[]) {
    Args args;

    // Parse flags
    std::vector<std::string> positional;
    for (int i = 1; i < argc; ++i) {
        std::string arg = argv[i];
        if (arg == "--address" && i + 1 < argc) {
            args.address = argv[++i];
        } else if (arg == "--help" || arg == "-h") {
            printUsage();
            return 0;
        } else {
            positional.push_back(arg);
        }
    }

    if (!positional.empty()) {
        args.command = positional[0];
        args.params.assign(positional.begin() + 1, positional.end());
    }

    // Connect
    smartbotic::database::Client client({.address = args.address});
    client.connect();

    // Scriptable mode: single command
    if (!args.command.empty()) {
        return execCommand(client, args.command, args.params) ? 0 : 1;
    }

    // Interactive mode
    std::cout << C_BOLD << "smartbotic-db-cli" << C_RESET
              << " connected to " << C_CYAN << args.address << C_RESET << "\n"
              << C_DIM << "Type 'help' for commands, 'exit' to quit." << C_RESET << "\n";

    std::string line;
    while (true) {
        std::cout << C_YELLOW << "> " << C_RESET;
        if (!std::getline(std::cin, line)) break;

        // Trim
        auto start = line.find_first_not_of(" \t");
        if (start == std::string::npos) continue;
        line = line.substr(start);

        if (line == "exit" || line == "quit" || line == "q") break;
        if (line.empty()) continue;

        auto tokens = tokenize(line);
        if (tokens.empty()) continue;

        auto cmd = tokens[0];
        std::vector<std::string> params(tokens.begin() + 1, tokens.end());
        execCommand(client, cmd, params);
    }

    return 0;
}