#include "FeedbackStore.h"
#include "sqlite3.h"
#include "json/json.h"
#include <chrono>
#include <cstring>
#include <sys/stat.h>

using namespace std;

// 创建路径的父目录（递归，类似 mkdir -p）
static void ensureParentDir(const string& filePath)
{
    size_t pos = filePath.find_last_of('/');
    if (pos == string::npos) return;          // 无目录部分
    string dir = filePath.substr(0, pos);
    if (dir.empty()) return;

    string cur;
    size_t start = 0;
    while (true) {
        size_t slash = dir.find('/', start);
        string part = (slash == string::npos) ? dir.substr(start)
                                              : dir.substr(start, slash - start);
        if (!part.empty()) {
            if (!cur.empty()) cur += '/';
            cur += part;
            mkdir(cur.c_str(), 0755);
        }
        if (slash == string::npos) break;
        start = slash + 1;
    }
}

FeedbackStore::FeedbackStore()
  : m_db(nullptr), m_appendStmt(nullptr)
{
}

FeedbackStore::~FeedbackStore()
{
    close();
}

static int64_t nowMs()
{
    using namespace std::chrono;
    return duration_cast<milliseconds>(system_clock::now().time_since_epoch()).count();
}

bool FeedbackStore::open(const string& path)
{
    lock_guard<mutex> lock(m_mutex);
    if (m_db) return true;

    ensureParentDir(path);

    if (sqlite3_open(path.c_str(), &m_db) != SQLITE_OK) {
        m_db = nullptr;
        return false;
    }

    const char* schema =
        "CREATE TABLE IF NOT EXISTS fb_log ("
        "  id INTEGER PRIMARY KEY AUTOINCREMENT,"
        "  ts INTEGER NOT NULL,"
        "  msg TEXT NOT NULL,"
        "  payload TEXT NOT NULL"
        ");"
        "CREATE INDEX IF NOT EXISTS idx_fb_log_msg_ts ON fb_log(msg, ts);";

    char* err = nullptr;
    if (sqlite3_exec(m_db, schema, nullptr, nullptr, &err) != SQLITE_OK) {
        sqlite3_free(err);
        sqlite3_close(m_db);
        m_db = nullptr;
        return false;
    }
    return true;
}

void FeedbackStore::close()
{
    lock_guard<mutex> lock(m_mutex);
    if (m_appendStmt) {
        sqlite3_finalize(m_appendStmt);
        m_appendStmt = nullptr;
    }
    if (m_db) {
        sqlite3_close(m_db);
        m_db = nullptr;
    }
}

bool FeedbackStore::begin()
{
    lock_guard<mutex> lock(m_mutex);
    if (!m_db) return false;
    char* err = nullptr;
    int rc = sqlite3_exec(m_db, "BEGIN;", nullptr, nullptr, &err);
    if (err) sqlite3_free(err);
    return rc == SQLITE_OK;
}

bool FeedbackStore::append(int64_t ts, const string& msg, const string& payload)
{
    lock_guard<mutex> lock(m_mutex);
    if (!m_db) return false;

    if (!m_appendStmt) {
        const char* sql = "INSERT INTO fb_log (ts, msg, payload) VALUES (?, ?, ?);";
        if (sqlite3_prepare_v2(m_db, sql, -1, &m_appendStmt, nullptr) != SQLITE_OK) {
            return false;
        }
    }

    sqlite3_bind_int64(m_appendStmt, 1, ts);
    sqlite3_bind_text(m_appendStmt, 2, msg.c_str(), -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(m_appendStmt, 3, payload.c_str(), -1, SQLITE_TRANSIENT);

    int rc = sqlite3_step(m_appendStmt);
    sqlite3_reset(m_appendStmt);
    sqlite3_clear_bindings(m_appendStmt);
    return rc == SQLITE_DONE;
}

bool FeedbackStore::commit()
{
    lock_guard<mutex> lock(m_mutex);
    if (!m_db) return false;
    char* err = nullptr;
    int rc = sqlite3_exec(m_db, "COMMIT;", nullptr, nullptr, &err);
    if (err) sqlite3_free(err);
    return rc == SQLITE_OK;
}

void FeedbackStore::prune(int64_t keepSeconds)
{
    lock_guard<mutex> lock(m_mutex);
    if (!m_db || keepSeconds <= 0) return;

    int64_t cutoff = nowMs() - keepSeconds * 1000;
    const char* sql = "DELETE FROM fb_log WHERE ts < ?;";
    sqlite3_stmt* stmt = nullptr;
    if (sqlite3_prepare_v2(m_db, sql, -1, &stmt, nullptr) == SQLITE_OK) {
        sqlite3_bind_int64(stmt, 1, cutoff);
        sqlite3_step(stmt);
        sqlite3_finalize(stmt);
    }
}

string FeedbackStore::querySeries(const string& msg, const string& field,
                                  int64_t fromTs, int64_t toTs, int limit)
{
    Json::Value result(Json::arrayValue);

    lock_guard<mutex> lock(m_mutex);
    if (!m_db || msg.empty() || field.empty()) {
        return "[]";
    }
    if (limit <= 0) limit = 2000;
    if (toTs <= 0) toTs = nowMs();

    const char* sql =
        "SELECT ts, payload FROM fb_log "
        "WHERE msg = ? AND ts >= ? AND ts <= ? ORDER BY ts ASC LIMIT ?;";

    sqlite3_stmt* stmt = nullptr;
    if (sqlite3_prepare_v2(m_db, sql, -1, &stmt, nullptr) != SQLITE_OK) {
        return "[]";
    }
    sqlite3_bind_text(stmt, 1, msg.c_str(), -1, SQLITE_TRANSIENT);
    sqlite3_bind_int64(stmt, 2, fromTs);
    sqlite3_bind_int64(stmt, 3, toTs);
    sqlite3_bind_int(stmt, 4, limit);

    Json::CharReaderBuilder builder;
    while (sqlite3_step(stmt) == SQLITE_ROW) {
        int64_t ts = sqlite3_column_int64(stmt, 0);
        const char* payload = (const char*)sqlite3_column_text(stmt, 1);
        if (!payload) continue;

        Json::Value root;
        JSONCPP_STRING errs;
        istringstream stream(payload);
        if (!Json::parseFromStream(builder, stream, &root, &errs)) continue;
        if (!root.isMember(field) || !root[field].isNumeric()) continue;

        Json::Value pt(Json::arrayValue);
        pt.append((Json::Int64)ts);
        pt.append(root[field].asDouble());
        result.append(pt);
    }
    sqlite3_finalize(stmt);

    Json::StreamWriterBuilder wb;
    wb.settings_["indentation"] = "";
    return Json::writeString(wb, result);
}

string FeedbackStore::queryRaw(const string& msg, int64_t fromTs, int64_t toTs, int limit)
{
    Json::Value result(Json::objectValue);
    Json::Value rows(Json::arrayValue);

    lock_guard<mutex> lock(m_mutex);
    if (m_db && !msg.empty()) {
        if (limit <= 0) limit = 500;
        if (toTs <= 0) toTs = nowMs();

        const char* sql =
            "SELECT ts, payload FROM fb_log "
            "WHERE msg = ? AND ts >= ? AND ts <= ? ORDER BY ts ASC LIMIT ?;";

        sqlite3_stmt* stmt = nullptr;
        if (sqlite3_prepare_v2(m_db, sql, -1, &stmt, nullptr) == SQLITE_OK) {
            sqlite3_bind_text(stmt, 1, msg.c_str(), -1, SQLITE_TRANSIENT);
            sqlite3_bind_int64(stmt, 2, fromTs);
            sqlite3_bind_int64(stmt, 3, toTs);
            sqlite3_bind_int(stmt, 4, limit);

            while (sqlite3_step(stmt) == SQLITE_ROW) {
                Json::Value row(Json::objectValue);
                row["ts"] = (Json::Int64)sqlite3_column_int64(stmt, 0);
                const char* p = (const char*)sqlite3_column_text(stmt, 1);
                row["payload"] = p ? p : "";
                rows.append(row);
            }
            sqlite3_finalize(stmt);
        }
    }

    result["rows"] = rows;
    Json::StreamWriterBuilder wb;
    wb.settings_["indentation"] = "";
    return Json::writeString(wb, result);
}