#include "m2_tokvec.h"

#include <algorithm>
#include <cctype>
#include <cstdlib>
#include <fstream>
#include <sstream>

namespace fmt {

namespace {

std::string lower(std::string s) {
    std::transform(s.begin(), s.end(), s.begin(),
                   [](unsigned char c) { return (char)std::tolower(c); });
    return s;
}

bool ieq(const std::string& a, const char* b) {
    return lower(a) == b;
}

// 一行 -> token 列表。`"..."` 单 token；`#` / `//` 到行尾注释。
std::vector<std::string> tokenize_line(const std::string& line) {
    std::vector<std::string> out;
    size_t i = 0, n = line.size();
    while (i < n) {
        char c = line[i];
        if (c == '#' || (c == '/' && i + 1 < n && line[i + 1] == '/')) break;
        if (std::isspace((unsigned char)c)) { ++i; continue; }
        if (c == '"') {
            ++i;
            std::string s;
            while (i < n && line[i] != '"') s += line[i++];
            if (i < n) ++i; // 收尾引号
            out.push_back(s);
            continue;
        }
        std::string s;
        while (i < n && !std::isspace((unsigned char)line[i]))
            s += line[i++];
        out.push_back(s);
    }
    return out;
}

} // namespace

bool TokVecMap::has(const std::string& key) const { return m.count(key) != 0; }

const std::vector<std::string>* TokVecMap::find(const std::string& key) const {
    auto it = m.find(lower(key));
    return it == m.end() ? nullptr : &it->second;
}

std::string TokVecMap::str(const std::string& key, const std::string& def) const {
    auto* v = find(key);
    return (v && !v->empty()) ? (*v)[0] : def;
}

long TokVecMap::inum(const std::string& key, long def) const {
    auto* v = find(key);
    return (v && !v->empty()) ? std::strtol((*v)[0].c_str(), nullptr, 10) : def;
}

double TokVecMap::num(const std::string& key, double def) const {
    auto* v = find(key);
    return (v && !v->empty()) ? std::strtod((*v)[0].c_str(), nullptr) : def;
}

bool parse_tokvec(const std::string& text, TokVecMap& out, std::string* err) {
    out = TokVecMap{};
    std::istringstream in(text);
    std::string line;

    std::string block_key;                 // 非空 = 正在收块
    std::vector<std::string> block_tokens;
    std::vector<std::string> seen_dups;

    auto commit = [&](const std::string& key, std::vector<std::string> toks) {
        std::string k = lower(key);
        if (out.m.count(k)) {
            out.dup_count++;
            if (std::find(seen_dups.begin(), seen_dups.end(), k) == seen_dups.end()) {
                seen_dups.push_back(k);
                out.dup_keys.push_back(k);
            }
            return; // 保留第一个
        }
        out.m.emplace(std::move(k), std::move(toks));
    };

    while (std::getline(in, line)) {
        if (!line.empty() && line.back() == '\r') line.pop_back();
        auto toks = tokenize_line(line);
        if (toks.empty()) continue;

        if (!block_key.empty()) {
            if (ieq(toks[0], "end")) {
                commit(block_key, std::move(block_tokens));
                block_key.clear();
                block_tokens.clear();
            } else {
                for (auto& t : toks) block_tokens.push_back(std::move(t));
            }
            continue;
        }

        if (ieq(toks[0], "start")) {
            if (toks.size() < 2) {
                if (err) *err = "Start 缺块名";
                return false;
            }
            block_key = toks[1];
            block_tokens.clear();
            continue;
        }

        // 顶层 `key v1 v2 ...`
        std::string key = toks[0];
        std::vector<std::string> vals(toks.begin() + 1, toks.end());
        commit(key, std::move(vals));
    }

    if (!block_key.empty()) {
        // 文件在块中截断 —— 宽容收尾但记 err
        commit(block_key, std::move(block_tokens));
        if (err) *err = "文件在 Start '" + block_key + "' 块中截断（缺 End）";
    }
    return true;
}

static FileReader g_file_reader = nullptr;
void set_file_reader(FileReader r) { g_file_reader = r; }

bool read_file(const std::string& path, std::string& out) {
    if (g_file_reader) return g_file_reader(path, out);
    std::ifstream f(path, std::ios::binary);
    if (!f) return false;
    std::ostringstream ss;
    ss << f.rdbuf();
    out = ss.str();
    return true;
}

bool parse_tokvec_file(const std::string& path, TokVecMap& out, std::string* err) {
    std::string text;
    if (!read_file(path, text)) {
        if (err) *err = "打不开文件: " + path;
        return false;
    }
    return parse_tokvec(text, out, err);
}

} // namespace fmt