#include "entity_ops.h"

#include "../../../../cpp/vendor/sqlite3/sqlite3.h"

#include <chrono>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cctype>

namespace ge {

// ----------------------------------------------------------------------------
// FNV1a-64 — debe coincidir con graph_sources.cpp
// ----------------------------------------------------------------------------
static uint64_t fnv1a64(const char* s) {
    uint64_t h = 1469598103934665603ULL;
    for (; s && *s; ++s) {
        h ^= (uint8_t)*s;
        h *= 1099511628211ULL;
    }
    return h;
}

// ----------------------------------------------------------------------------
// Heuristicas — sin <regex> para evitar peso. Inspeccion lineal del string.
// ----------------------------------------------------------------------------

static bool is_email(const char* s) {
    if (!s || !*s) return false;
    const char* at = std::strchr(s, '@');
    if (!at || at == s) return false;
    if (std::strchr(at + 1, '@')) return false;          // dos @
    const char* dot = std::strchr(at + 1, '.');
    if (!dot || dot[1] == 0) return false;
    if (std::strchr(s, ' ')) return false;
    return true;
}

static bool is_ipv4(const char* s) {
    if (!s || !*s) return false;
    int parts = 0, digits = 0, n = 0;
    for (const char* p = s; ; ++p) {
        if (*p >= '0' && *p <= '9') {
            n = n * 10 + (*p - '0');
            if (++digits > 3 || n > 255) return false;
        } else if (*p == '.' || *p == 0) {
            if (digits == 0) return false;
            ++parts; digits = 0; n = 0;
            if (*p == 0) break;
        } else {
            return false;
        }
    }
    return parts == 4;
}

static bool is_url(const char* s) {
    if (!s) return false;
    return std::strncmp(s, "http://", 7) == 0 || std::strncmp(s, "https://", 8) == 0;
}

static bool is_domain(const char* s) {
    if (!s || !*s) return false;
    if (std::strchr(s, ' ') || std::strchr(s, '@') || std::strchr(s, '/')) return false;
    const char* dot = std::strchr(s, '.');
    if (!dot || dot == s || dot[1] == 0) return false;
    // El TLD debe ser al menos 2 caracteres alfabeticos
    int tld = 0;
    for (const char* p = std::strrchr(s, '.') + 1; *p; ++p) {
        if (!std::isalpha((unsigned char)*p)) return false;
        ++tld;
    }
    return tld >= 2;
}

static bool is_phone(const char* s) {
    if (!s || !*s) return false;
    int digits = 0;
    for (const char* p = s; *p; ++p) {
        if (*p >= '0' && *p <= '9') ++digits;
        else if (*p == '+' || *p == ' ' || *p == '-' || *p == '(' || *p == ')' || *p == '.') {}
        else return false;
    }
    return digits >= 7 && digits <= 15;
}

DetectedType detect_type(const char* text) {
    if (!text || !*text) return DT_TEXT;
    if (is_email(text))  return DT_EMAIL;
    if (is_ipv4(text))   return DT_IP_ADDRESS;
    if (is_url(text))    return DT_URL;
    if (is_phone(text))  return DT_PHONE;  // antes que domain (numeros con puntos)
    if (is_domain(text)) return DT_DOMAIN;
    return DT_TEXT;
}

const char* detected_type_name(DetectedType dt) {
    switch (dt) {
        case DT_EMAIL:      return "email";
        case DT_IP_ADDRESS: return "ip_address";
        case DT_URL:        return "url";
        case DT_DOMAIN:     return "domain";
        case DT_PHONE:      return "phone";
        case DT_TEXT:
        default:            return "text";
    }
}

// ----------------------------------------------------------------------------
// SQLite helpers
// ----------------------------------------------------------------------------

static bool exec_one(sqlite3* db, const char* sql,
                     const char** params, int n_params)
{
    sqlite3_stmt* st = nullptr;
    if (sqlite3_prepare_v2(db, sql, -1, &st, nullptr) != SQLITE_OK) return false;
    for (int i = 0; i < n_params; ++i) {
        sqlite3_bind_text(st, i + 1, params[i] ? params[i] : "", -1, SQLITE_TRANSIENT);
    }
    int rc = sqlite3_step(st);
    sqlite3_finalize(st);
    return rc == SQLITE_DONE;
}

static std::string now_iso() {
    using namespace std::chrono;
    auto t = system_clock::to_time_t(system_clock::now());
    char buf[32];
    std::strftime(buf, sizeof(buf), "%Y-%m-%dT%H:%M:%S", std::gmtime(&t));
    return std::string(buf) + "Z";
}

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

// ----------------------------------------------------------------------------
// CRUD
// ----------------------------------------------------------------------------

bool entity_insert(const char* db_path, const char* name, const char* type_ref,
                   char* out_id, size_t out_id_n)
{
    if (!db_path || !name || !*name || !out_id || out_id_n < 32) return false;

    std::string tref;
    if (type_ref && *type_ref) {
        tref = type_ref;
    } else {
        tref = detected_type_name(detect_type(name));
    }

    std::snprintf(out_id, out_id_n, "%s_%lld", tref.c_str(), now_ms());
    std::string ts = now_iso();

    sqlite3* db = nullptr;
    if (sqlite3_open_v2(db_path, &db, SQLITE_OPEN_READWRITE, nullptr) != SQLITE_OK) {
        if (db) sqlite3_close(db);
        return false;
    }
    const char* sql =
        "INSERT INTO entities (id, name, type_ref, source, created_at, updated_at) "
        "VALUES (?, ?, ?, 'manual', ?, ?)";
    const char* params[5] = { out_id, name, tref.c_str(), ts.c_str(), ts.c_str() };
    bool ok = exec_one(db, sql, params, 5);
    sqlite3_close(db);
    return ok;
}

bool entity_delete(const char* db_path, const char* id) {
    if (!db_path || !id) return false;
    sqlite3* db = nullptr;
    if (sqlite3_open_v2(db_path, &db, SQLITE_OPEN_READWRITE, nullptr) != SQLITE_OK) {
        if (db) sqlite3_close(db);
        return false;
    }
    const char* p_rel[2] = { id, id };
    const char* p_ent[1] = { id };
    exec_one(db, "DELETE FROM relations WHERE from_entity = ? OR to_entity = ?", p_rel, 2);
    bool ok = exec_one(db, "DELETE FROM entities WHERE id = ?", p_ent, 1);
    sqlite3_close(db);
    return ok;
}

bool entity_update_type(const char* db_path, const char* id, const char* new_type) {
    if (!db_path || !id || !new_type) return false;
    sqlite3* db = nullptr;
    if (sqlite3_open_v2(db_path, &db, SQLITE_OPEN_READWRITE, nullptr) != SQLITE_OK) {
        if (db) sqlite3_close(db);
        return false;
    }
    std::string ts = now_iso();
    const char* p[3] = { new_type, ts.c_str(), id };
    bool ok = exec_one(db, "UPDATE entities SET type_ref = ?, updated_at = ? WHERE id = ?", p, 3);
    sqlite3_close(db);
    return ok;
}

bool entity_duplicate(const char* db_path, const char* id,
                      char* out_id, size_t out_id_n)
{
    if (!db_path || !id || !out_id || out_id_n < 32) return false;
    sqlite3* db = nullptr;
    if (sqlite3_open_v2(db_path, &db, SQLITE_OPEN_READWRITE, nullptr) != SQLITE_OK) {
        if (db) sqlite3_close(db);
        return false;
    }
    sqlite3_stmt* st = nullptr;
    const char* sel = "SELECT name, type_ref, description, domain, tags, source, metadata, notes "
                      "FROM entities WHERE id = ?";
    if (sqlite3_prepare_v2(db, sel, -1, &st, nullptr) != SQLITE_OK) {
        sqlite3_close(db);
        return false;
    }
    sqlite3_bind_text(st, 1, id, -1, SQLITE_TRANSIENT);
    if (sqlite3_step(st) != SQLITE_ROW) {
        sqlite3_finalize(st);
        sqlite3_close(db);
        return false;
    }
    auto col = [&](int i) {
        const unsigned char* p = sqlite3_column_text(st, i);
        return std::string(p ? (const char*)p : "");
    };
    std::string name  = col(0) + " (copia)";
    std::string tref  = col(1);
    std::string desc  = col(2);
    std::string dom   = col(3);
    std::string tags  = col(4);
    std::string src   = col(5);
    std::string meta  = col(6);
    std::string notes = col(7);
    sqlite3_finalize(st);

    std::snprintf(out_id, out_id_n, "%s_%lld", tref.c_str(), now_ms());
    std::string ts = now_iso();

    const char* ins =
        "INSERT INTO entities (id, name, type_ref, description, domain, tags, source, "
        "metadata, notes, created_at, updated_at) "
        "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
    sqlite3_stmt* ist = nullptr;
    if (sqlite3_prepare_v2(db, ins, -1, &ist, nullptr) != SQLITE_OK) {
        sqlite3_close(db);
        return false;
    }
    sqlite3_bind_text(ist,  1, out_id,       -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(ist,  2, name.c_str(), -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(ist,  3, tref.c_str(), -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(ist,  4, desc.c_str(), -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(ist,  5, dom.c_str(),  -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(ist,  6, tags.c_str(), -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(ist,  7, src.c_str(),  -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(ist,  8, meta.c_str(), -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(ist,  9, notes.c_str(),-1, SQLITE_TRANSIENT);
    sqlite3_bind_text(ist, 10, ts.c_str(),   -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(ist, 11, ts.c_str(),   -1, SQLITE_TRANSIENT);
    bool ok = sqlite3_step(ist) == SQLITE_DONE;
    sqlite3_finalize(ist);
    sqlite3_close(db);
    return ok;
}

bool relation_insert(const char* db_path, const char* from_id, const char* to_id,
                     const char* name)
{
    if (!db_path || !from_id || !to_id) return false;
    const char* rel = (name && *name) ? name : k_default_relation_name;
    sqlite3* db = nullptr;
    if (sqlite3_open_v2(db_path, &db, SQLITE_OPEN_READWRITE, nullptr) != SQLITE_OK) {
        if (db) sqlite3_close(db);
        return false;
    }
    char id[64];
    std::snprintf(id, sizeof(id), "rel_%lld", now_ms());
    std::string ts = now_iso();
    const char* sql =
        "INSERT INTO relations (id, name, from_entity, to_entity, created_at, updated_at) "
        "VALUES (?, ?, ?, ?, ?, ?)";
    const char* params[6] = { id, rel, from_id, to_id, ts.c_str(), ts.c_str() };
    bool ok = exec_one(db, sql, params, 6);
    sqlite3_close(db);
    return ok;
}

// ----------------------------------------------------------------------------
// Index user_data -> sql id
// ----------------------------------------------------------------------------

bool entity_index_build(const char* db_path, EntityIndex* idx) {
    if (!db_path || !idx) return false;
    idx->by_hash.clear();
    sqlite3* db = nullptr;
    if (sqlite3_open_v2(db_path, &db, SQLITE_OPEN_READONLY, nullptr) != SQLITE_OK) {
        if (db) sqlite3_close(db);
        return false;
    }
    sqlite3_stmt* st = nullptr;
    if (sqlite3_prepare_v2(db, "SELECT id FROM entities", -1, &st, nullptr) != SQLITE_OK) {
        sqlite3_close(db);
        return false;
    }
    while (sqlite3_step(st) == SQLITE_ROW) {
        const unsigned char* p = sqlite3_column_text(st, 0);
        if (!p) continue;
        const char* id = (const char*)p;
        idx->by_hash.emplace(fnv1a64(id), std::string(id));
    }
    sqlite3_finalize(st);
    sqlite3_close(db);
    return true;
}

const char* entity_index_lookup(const EntityIndex& idx, uint64_t user_data) {
    auto it = idx.by_hash.find(user_data);
    return (it == idx.by_hash.end()) ? nullptr : it->second.c_str();
}

} // namespace ge