#include "tape_config.h"
#include "tapelib/filetape.h"
#include <bits/getopt_core.h>
#include <chrono>
#include <cstddef>
#include <fstream>
#include <getopt.h>
#include <iostream>
#include <stdexcept>
#include <string>
#include <vector>

using std::string;
using std::chrono::milliseconds;

const static struct std::vector<option> CMD_OPTS{
    {.name = "write-delay",
     .has_arg = no_argument,
     .flag = nullptr,
     .val = 'w'},
    {.name = "read-delay", .has_arg = no_argument, .flag = nullptr, .val = 'r'},
    {.name = "seek-forward-delay",
     .has_arg = no_argument,
     .flag = nullptr,
     .val = 'f'},
    {.name = "seek-backwards-delay",
     .has_arg = no_argument,
     .flag = nullptr,
     .val = 'b'},
    {.name = "memory-limit",
     .has_arg = no_argument,
     .flag = nullptr,
     .val = 'm'},
    {.name = "config-file",
     .has_arg = no_argument,
     .flag = nullptr,
     .val = 'c'},
    {.name = "version", .has_arg = no_argument, .flag = nullptr, .val = 'v'},
    {.name = "help", .has_arg = no_argument, .flag = nullptr, .val = 'h'},
    {.name = nullptr, .has_arg = no_argument, .flag = nullptr, .val = 0}};

milliseconds parse_delay(const string &input) {
    int delay_ms = std::stoi(input);
    return milliseconds(delay_ms);
}

AppSettings parse_command_line(int argc, char **argv) {
    AppSettings settings{
        .config_file_path = "",
        .input_file_name = "",
        .output_file_name = "",
        .memory_limit = SIZE_MAX,
        .version = false,
        .help = false,
        .ft_settings = tape::FT_DEFAULT_SETTINGS,
    };
    int opt_index = 0;
    int opt = 0;
    // parse [OPTIONS...] using getopt_long
    while ((opt = getopt_long(argc, argv, "r:w:f:b:m:c:vh", CMD_OPTS.data(),
                              &opt_index)) != -1) {
        switch (opt) {
        case 'r':
            settings.ft_settings.read_delay = parse_delay(optarg);
            break;
        case 'w':
            settings.ft_settings.write_delay = parse_delay(optarg);
            break;
        case 'f':
            settings.ft_settings.seek_forward_delay = parse_delay(optarg);
            break;
        case 'b':
            settings.ft_settings.seek_backwards_delay = parse_delay(optarg);
            break;
        case 'm':
            settings.memory_limit = std::stoi(optarg);
            break;
        case 'c':
            settings.config_file_path = optarg;
            break;
        case 'v':
            settings.version = true;
            break;
        case 'h':
        case '?':
        default:
            settings.help = true;
            break;
        }
    }
    // parse positional args INPUT_FILE OUTPUT_FILE
    if (argc - optind < 2) {
        settings.help = true;
        std::cerr << "Not enough positional arguments (Missing INPUT_FILE or "
                     "OUTPUT_FILE)"
                  << std::endl;
        return settings;
    }
    // no linting to disable pointer arithmetic warning
    settings.input_file_name = argv[optind];      // NOLINT
    settings.output_file_name = argv[optind + 1]; // NOLINT
    return settings;
}

const static char CFG_DELIMETER = '=';

bool read_settings_from_file(AppSettings &settings) {
    std::ifstream config(settings.config_file_path);
    if (!config.is_open()) {
        std::cerr << "Failed to read config: file doesn't exist or "
                     "insufficient permissions"
                  << std::endl;
        return false;
    }
    string line;
    size_t line_number = 1;
    while (std::getline(config, line)) {
        size_t delim_index = line.find(CFG_DELIMETER);
        if (delim_index >= line.size()) {
            continue;
        }
        string key = line.substr(0, delim_index);
        string value = line.substr(delim_index + 1);
        try {
            if (key == "write-delay") {
                settings.ft_settings.write_delay = parse_delay(value);
            } else if (key == "read-delay") {
                settings.ft_settings.read_delay = parse_delay(value);
            } else if (key == "seek-forward-delay") {
                settings.ft_settings.seek_forward_delay = parse_delay(value);
            } else if (key == "seek-backwards-delay") {
                settings.ft_settings.seek_backwards_delay = parse_delay(value);
            } else if (key == "memory-limit") {
                settings.memory_limit = std::stoi(value);
            }
        } catch (std::invalid_argument) {
            std::cerr << "Failed to parse config at line " << line_number
                      << ": value must be a positive integer" << std::endl;
            return false;
        } catch (std::out_of_range) {
            std::cerr << "Failed to parse config at line " << line_number
                      << ": value is out of allowed range" << std::endl;
            return false;
        }
        line_number++;
    }
    return true;
}