#include "db.h"
#include <sqlite3.h>
#include <iostream>
#include <fstream>

sqlite3* db = nullptr;

// --- Connexion / fermeture ---
bool openDB(const std::string& filename) {
    int rc = sqlite3_open(filename.c_str(), &db);
    if(rc) {
        std::cerr << "Impossible d'ouvrir la base : " << sqlite3_errmsg(db) << "\n";
        return false;
    }
    return true;
}

void closeDB() {
    if(db) sqlite3_close(db);
}

// --- Authentification ---
int loginUser(const std::string& login, const std::string& password) {
    sqlite3_stmt* stmt;
    std::string sql = "SELECT id, role FROM users WHERE login=? AND password=?";
    sqlite3_prepare_v2(db, sql.c_str(), -1, &stmt, nullptr);
    sqlite3_bind_text(stmt, 1, login.c_str(), -1, SQLITE_STATIC);
    sqlite3_bind_text(stmt, 2, password.c_str(), -1, SQLITE_STATIC);

    int role = -1;
    int rc = sqlite3_step(stmt);
    if(rc == SQLITE_ROW) {
        role = sqlite3_column_int(stmt, 1); // 0=ADMIN, 1=PROF, 2=STUDENT
    }
    sqlite3_finalize(stmt);
    return role;
}

// --- Étudiants ---
std::vector<Student> getAllStudents() {
    std::vector<Student> list;
    sqlite3_stmt* stmt;
    std::string sql = "SELECT s.id, s.nom, n.note1, n.note2, n.note3 FROM students s JOIN notes n ON s.id=n.student_id";
    sqlite3_prepare_v2(db, sql.c_str(), -1, &stmt, nullptr);

    while(sqlite3_step(stmt) == SQLITE_ROW) {
        Student s;
        s.id = sqlite3_column_int(stmt, 0);
        s.nom = reinterpret_cast<const char*>(sqlite3_column_text(stmt, 1));
        s.notes[0] = sqlite3_column_int(stmt, 2);
        s.notes[1] = sqlite3_column_int(stmt, 3);
        s.notes[2] = sqlite3_column_int(stmt, 4);
        list.push_back(s);
    }
    sqlite3_finalize(stmt);
    return list;
}

Student getStudentByLogin(const std::string& login) {
    Student s;
    sqlite3_stmt* stmt;
    std::string sql = "SELECT s.id, s.nom, n.note1, n.note2, n.note3 FROM students s JOIN notes n ON s.id=n.student_id WHERE s.nom=?";
    sqlite3_prepare_v2(db, sql.c_str(), -1, &stmt, nullptr);
    sqlite3_bind_text(stmt, 1, login.c_str(), -1, SQLITE_STATIC);

    if(sqlite3_step(stmt) == SQLITE_ROW){
        s.id = sqlite3_column_int(stmt, 0);
        s.nom = reinterpret_cast<const char*>(sqlite3_column_text(stmt, 1));
        s.notes[0] = sqlite3_column_int(stmt, 2);
        s.notes[1] = sqlite3_column_int(stmt, 3);
        s.notes[2] = sqlite3_column_int(stmt, 4);
    }
    sqlite3_finalize(stmt);
    return s;
}

// --- Modifier une note ---
bool updateNote(int studentId, int noteIndex, int newNote) {
    std::string col = "note" + std::to_string(noteIndex+1);
    std::string sql = "UPDATE notes SET " + col + "=? WHERE student_id=?";
    sqlite3_stmt* stmt;
    sqlite3_prepare_v2(db, sql.c_str(), -1, &stmt, nullptr);
    sqlite3_bind_int(stmt, 1, newNote);
    sqlite3_bind_int(stmt, 2, studentId);

    int rc = sqlite3_step(stmt);
    sqlite3_finalize(stmt);
    return rc == SQLITE_DONE;
}

// --- Export / Import ---
bool exportData(const std::string& filename, const std::string& role, const std::string& login) {
    std::ofstream file(filename);
    if(!file.is_open()) return false;

    std::vector<Student> list;
    if(role == "ADMIN" || role == "PROF") list = getAllStudents();
    else list.push_back(getStudentByLogin(login));

    for(auto& s : list){
        file << s.nom << " " << s.notes[0] << " " << s.notes[1] << " " << s.notes[2] << "\n";
    }
    file.close();
    return true;
}

bool importData(const std::string& filename, const std::string& role) {
    if(role == "STUDENT") return false; // pas autorisé

    std::ifstream file(filename);
    if(!file.is_open()) return false;

    std::string nom;
    int n1,n2,n3;
    while(file >> nom >> n1 >> n2 >> n3){
        if(role == "ADMIN"){
            // chercher étudiant
            sqlite3_stmt* stmt;
            std::string sql = "UPDATE notes SET note1=?, note2=?, note3=? WHERE student_id=(SELECT id FROM students WHERE nom=?)";
            sqlite3_prepare_v2(db, sql.c_str(), -1, &stmt, nullptr);
            sqlite3_bind_int(stmt, 1, n1);
            sqlite3_bind_int(stmt, 2, n2);
            sqlite3_bind_int(stmt, 3, n3);
            sqlite3_bind_text(stmt, 4, nom.c_str(), -1, SQLITE_STATIC);
            sqlite3_step(stmt);
            sqlite3_finalize(stmt);
        } else if(role == "PROF"){
            // modification notes seulement
            sqlite3_stmt* stmt;
            std::string sql = "UPDATE notes SET note1=?, note2=?, note3=? WHERE student_id=(SELECT id FROM students WHERE nom=?)";
            sqlite3_prepare_v2(db, sql.c_str(), -1, &stmt, nullptr);
            sqlite3_bind_int(stmt, 1, n1);
            sqlite3_bind_int(stmt, 2, n2);
            sqlite3_bind_int(stmt, 3, n3);
            sqlite3_bind_text(stmt, 4, nom.c_str(), -1, SQLITE_STATIC);
            sqlite3_step(stmt);
            sqlite3_finalize(stmt);
        }
    }

    file.close();
    return true;
}