// gKeyMapper - mappings file parsing/formatting.

#include "mapping.h"

#include <cstdio>
#include <cstdlib>
#include <fstream>
#include <sstream>

#include "keys.h"

namespace gkeymapper {

const char* action_type_token(ActionType type) {
    switch (type) {
        case ActionType::Key:
            return "key";
        case ActionType::Command:
            return "command";
        case ActionType::KeyHold:
            return "keyhold";
        case ActionType::Disabled:
        default:
            return "disabled";
    }
}

ActionType action_type_from_token(const std::string& token) {
    if (token == "key") {
        return ActionType::Key;
    }
    if (token == "command") {
        return ActionType::Command;
    }
    if (token == "keyhold") {
        return ActionType::KeyHold;
    }
    return ActionType::Disabled;
}

std::string format_mappings(const MappingSet& set) {
    std::string out = "# gKeyMapper mappings (G1..G9)\n";
    for (int i = 0; i < kNumKeys; ++i) {
        Mapping mapping;
        if (i < static_cast<int>(set.keys.size())) {
            mapping = set.keys[i];
        }
        out += "G";
        out += std::to_string(i + 1);
        out += "=";
        out += action_type_token(mapping.type);
        out += ":";
        out += mapping.target;
        out += "\n";
    }
    return out;
}

MappingSet parse_mappings(const std::string& text) {
    MappingSet set;
    set.keys.assign(kNumKeys, Mapping{});

    std::istringstream in(text);
    std::string line;
    while (std::getline(in, line)) {
        if (line.empty() || line[0] == '#') {
            continue;
        }
        auto eq = line.find('=');
        if (eq == std::string::npos) {
            continue;
        }
        std::string key = line.substr(0, eq);
        if (key.size() < 2 || key[0] != 'G') {
            continue;
        }
        int n = 0;
        try {
            n = std::stoi(key.substr(1)) - 1;
        } catch (...) {
            continue;
        }
        if (n < 0 || n >= kNumKeys) {
            continue;
        }

        std::string rest = line.substr(eq + 1);
        auto col = rest.find(':');
        std::string typeToken = (col == std::string::npos) ? rest : rest.substr(0, col);
        std::string target = (col == std::string::npos) ? std::string() : rest.substr(col + 1);

        set.keys[n].type = action_type_from_token(typeToken);
        set.keys[n].target = target;
    }
    return set;
}

bool load_mappings_file(const std::string& path, MappingSet& out) {
    std::ifstream in(path);
    if (!in) {
        return false;
    }
    std::stringstream buffer;
    buffer << in.rdbuf();
    out = parse_mappings(buffer.str());
    return true;
}

bool save_mappings_file(const std::string& path, const MappingSet& set) {
    // Write a temporary file first and rename it into place: a reader (the
    // daemon) either sees the old or the new file, never a half-written one.
    const std::string tempPath = path + ".tmp";
    {
        std::ofstream out(tempPath);
        if (!out) {
            return false;
        }
        out << format_mappings(set);
        out.flush();
        if (!out) {
            return false;
        }
    }
    return std::rename(tempPath.c_str(), path.c_str()) == 0;
}

std::string default_config_path() {
    const char* home = std::getenv("HOME");
    return std::string(home ? home : "") + "/.config/gKeyMapper/mappings.conf";
}

std::string format_shortcut_step(unsigned modifiers, const std::string& key_name) {
    std::string step;
    if ((modifiers & kModCtrl) != 0) {
        step += "ctrl+";
    }
    if ((modifiers & kModAlt) != 0) {
        step += "alt+";
    }
    if ((modifiers & kModShift) != 0) {
        step += "shift+";
    }
    if ((modifiers & kModSuper) != 0) {
        step += "super+";
    }
    if ((modifiers & kModAltGr) != 0) {
        step += "altgr+";
    }
    step += key_name;
    return step;
}

bool parse_shortcut(const std::string& text, std::vector<ShortcutStep>& out,
                    const KeyResolver& resolve) {
    out.clear();
    if (text.empty()) {
        return false;
    }

    std::istringstream combos(text);
    std::string combo;
    while (std::getline(combos, combo, ',')) {
        if (combo.empty()) {
            return false;
        }

        ShortcutStep step;
        bool haveKey = false;

        std::istringstream parts(combo);
        std::string part;
        while (std::getline(parts, part, '+')) {
            if (part.empty()) {
                return false;
            }
            unsigned mod = modifier_bit(part);
            if (mod != kModNone) {
                step.modifiers |= mod;
                continue;
            }
            int code = resolve ? resolve(part) : linux_key_code(part);
            if (code < 0) {
                return false; // unknown key name
            }
            step.key_name = part;
            step.linux_key = code;
            haveKey = true;
        }

        if (!haveKey) {
            return false; // combo without an actual key
        }
        out.push_back(step);
    }
    return !out.empty();
}

} // namespace gkeymapper