const db = require("../db");

function showCreatePatient(req, res) {
  res.render("patient_create");
}

function createPatient(req, res) {
  const { firstname, lastname, birthdate } = req.body;

  db.query(
    "INSERT INTO patients (firstname, lastname, birthdate, active) VALUES (?, ?, ?, 1)",
    [firstname, lastname, birthdate],
    err => {
      if (err) {
        console.error(err);
        return res.send("Datenbankfehler");
      }
      res.redirect("/dashboard");
    }
  );
}

function listPatients(req, res) {
  const { firstname, lastname, birthdate } = req.query;

  let sql = "SELECT * FROM patients WHERE 1=1";
  const params = [];

  if (firstname) { sql += " AND firstname LIKE ?"; params.push(`%${firstname}%`); }
  if (lastname) { sql += " AND lastname LIKE ?"; params.push(`%${lastname}%`); }
  if (birthdate) { sql += " AND birthdate = ?"; params.push(birthdate); }

  sql += " ORDER BY lastname, firstname";

  db.query(sql, params, (err, patients) => {
    if (err) return res.send("Datenbankfehler");
    res.render("patients", {  patients,  query: req.query,  user: req.session.user});
  });
}

function showEditPatient(req, res) {
  db.query(
    "SELECT * FROM patients WHERE id = ?",
    [req.params.id],
    (err, results) => {
      if (err || results.length === 0) return res.send("Patient nicht gefunden");
      res.render("patient_edit", {
        patient: results[0],
        error: null,
        user: req.session.user,
        returnTo: req.query.returnTo || null
      });
    }
  );
}

function updatePatient(req, res) {
  const id = req.params.id;
  const returnTo = req.body.returnTo;

  const {
    firstname,
    lastname,
    dni,
    birthdate,
    gender,
    email,
    phone,
    street,
    house_number,
    postal_code,
    city,
    country,
    notes
  } = req.body;

  if (!firstname || !lastname || !birthdate) {
    req.session.flash = {
      type: "warning",
      message: "Vorname, Nachname und Geburtsdatum sind Pflichtfelder"
    };
    return res.redirect("back");
  }

  db.query(
    `UPDATE patients SET
      firstname = ?,
      lastname = ?,
      dni = ?,
      birthdate = ?,
      gender = ?,
      email = ?,
      phone = ?,
      street = ?,
      house_number = ?,
      postal_code = ?,
      city = ?,
      country = ?,
      notes = ?
     WHERE id = ?`,
    [
      firstname,
      lastname,
      dni || null,
      birthdate,
      gender || null,
      email || null,
      phone || null,
      street || null,
      house_number || null,
      postal_code || null,
      city || null,
      country || null,
      notes || null,
      id
    ],
    err => {
      if (err) {
        console.error(err);
        return res.send("Fehler beim Speichern");
      }

      if (returnTo === "overview") {
        return res.redirect(`/patients/${id}/overview`);
      }

      res.redirect("/patients");
    }
  );
}

function showPatientMedications(req, res) {
  const patientId = req.params.id;
  const returnTo = req.query.returnTo || null;

  const patientSql = "SELECT * FROM patients WHERE id = ?";
  const medsSql = `
    SELECT
      v.id,
      m.name AS medication,
      f.name AS form,
      v.dosage,
      v.package
    FROM medication_variants v
    JOIN medications m ON v.medication_id = m.id
    JOIN medication_forms f ON v.form_id = f.id
    ORDER BY m.name, v.dosage
  `;

  const currentSql = `
    SELECT
      pm.id,
      m.name AS medication,
      f.name AS form,
      v.dosage,
      v.package,
      pm.dosage_instruction,
      pm.start_date,
      pm.end_date
    FROM patient_medications pm
    JOIN medication_variants v ON pm.medication_variant_id = v.id
    JOIN medications m ON v.medication_id = m.id
    JOIN medication_forms f ON v.form_id = f.id
    WHERE pm.patient_id = ?
    ORDER BY pm.start_date DESC
  `;

  db.query(patientSql, [patientId], (err, patients) => {
    if (err || patients.length === 0) {
      return res.send("Patient nicht gefunden");
    }

    db.query(medsSql, (err, meds) => {
      if (err) return res.send("Medikamente konnten nicht geladen werden");

      db.query(currentSql, [patientId], (err, currentMeds) => {
        if (err) return res.send("Aktuelle Medikation konnte nicht geladen werden");

        res.render("patient_medications", {
          patient: patients[0],
          meds,
          currentMeds,
          user: req.session.user,
          returnTo
        });
      });
    });
  });
}

function moveToWaitingRoom(req, res) {
  const id = req.params.id;

  db.query(
    `
    UPDATE patients
    SET waiting_room = 1,
        discharged = 0
    WHERE id = ?
    `,
    [id],
    err => {
      if (err) return res.send("Fehler beim Verschieben ins Wartezimmer");
      res.redirect("/patients");
    }
  );
}

function showWaitingRoom(req, res) {
  db.query(
    "SELECT * FROM patients WHERE waiting_room = 1 AND active = 1 ORDER BY lastname",
    (err, patients) => {
      if (err) return res.send("Datenbankfehler");

      res.render("waiting_room", {
        patients,
        user: req.session.user
      });
    }
  );
}

function showPatientOverview(req, res) {
  const patientId = req.params.id;

  const patientSql = `
    SELECT *
    FROM patients
    WHERE id = ?
  `;

  const notesSql = `
    SELECT *
    FROM patient_notes
    WHERE patient_id = ?
    ORDER BY created_at DESC
  `;

  // 🔤 Services dynamisch nach Sprache laden
  const servicesSql = (nameField) => `
    SELECT
      id,
      ${nameField} AS name,
      price
    FROM services
    WHERE active = 1
    ORDER BY ${nameField}
  `;

  db.query(patientSql, [patientId], (err, patients) => {
    if (err || patients.length === 0) {
      return res.send("Patient nicht gefunden");
    }

    const patient = patients[0];

    // 🇪🇸 / 🇩🇪 Sprache bestimmen
    const serviceNameField =
      patient.country === "ES"
        ? "COALESCE(NULLIF(name_es, ''), name_de)"
        : "name_de";

    const todayServicesSql = `
      SELECT
        ps.id,
        ps.quantity,
        COALESCE(ps.price_override, s.price) AS price,
        ${serviceNameField} AS name,
        u.username AS doctor
      FROM patient_services ps
      JOIN services s ON ps.service_id = s.id
      LEFT JOIN users u ON ps.created_by = u.id
      WHERE ps.patient_id = ?
        AND ps.service_date = CURDATE()
        AND ps.invoice_id IS NULL
      ORDER BY ps.created_at DESC
    `;

    db.query(notesSql, [patientId], (err, notes) => {
      if (err) return res.send("Fehler Notizen");

      db.query(servicesSql(serviceNameField), (err, services) => {
        if (err) return res.send("Fehler Leistungen");

        db.query(todayServicesSql, [patientId], (err, todayServices) => {
          if (err) return res.send("Fehler heutige Leistungen");

          res.render("patient_overview", {
            patient,
            notes,
            services,
            todayServices,
            user: req.session.user
          });
        });
      });
    });
  });
}


function addPatientNote(req, res) {
  const patientId = req.params.id;
  const { note } = req.body;

  if (!note || note.trim() === "") {
    return res.redirect(`/patients/${patientId}/overview`);
  }

  db.query(
    "INSERT INTO patient_notes (patient_id, note) VALUES (?, ?)",
    [patientId, note],
    err => {
      if (err) return res.send("Fehler beim Speichern der Notiz");
      res.redirect(`/patients/${patientId}/overview`);
    }
  );
}

function callFromWaitingRoom(req, res) {
  const patientId = req.params.id;

  db.query(
    "UPDATE patients SET waiting_room = 0 WHERE id = ?",
    [patientId],
    err => {
      if (err) return res.send("Fehler beim Entfernen aus dem Wartezimmer");
      res.redirect(`/patients/${patientId}/overview`);
    }
  );
}

function dischargePatient(req, res) {
  const patientId = req.params.id;

  db.query(
    "UPDATE patients SET discharged = 1 WHERE id = ?",
    [patientId],
    err => {
      if (err) return res.send("Fehler beim Entlassen des Patienten");
      res.redirect("/waiting-room");
    }
  );
}

function showMedicationPlan(req, res) {
  const patientId = req.params.id;

  const patientSql = "SELECT * FROM patients WHERE id = ?";
  const medsSql = `
    SELECT
      m.name AS medication,
      f.name AS form,
      v.dosage,
      v.package,
      pm.dosage_instruction,
      pm.start_date,
      pm.end_date
    FROM patient_medications pm
    JOIN medication_variants v ON pm.medication_variant_id = v.id
    JOIN medications m ON v.medication_id = m.id
    JOIN medication_forms f ON v.form_id = f.id
    WHERE pm.patient_id = ?
      AND (pm.end_date IS NULL OR pm.end_date >= CURDATE())
    ORDER BY m.name
  `;

  db.query(patientSql, [patientId], (err, patients) => {
    if (err || patients.length === 0) {
      return res.send("Patient nicht gefunden");
    }

    db.query(medsSql, [patientId], (err, meds) => {
      if (err) return res.send("Medikationsplan konnte nicht geladen werden");

      res.render("patient_plan", {
        patient: patients[0],
        meds
      });
    });
  });
}

function movePatientToWaitingRoom(req, res) {
  const patientId = req.params.id;

  db.query(
    `
    UPDATE patients
    SET waiting_room = 1,
        discharged = 0
    WHERE id = ?
    `,
    [patientId],
    err => {
      if (err) {
        console.error(err);
        req.session.flash = {
          type: "danger",
          message: "Fehler beim Zurücksetzen ins Wartezimmer"
        };
        return res.redirect(`/patients/${patientId}/overview`);
      }

      req.session.flash = {
        type: "success",
        message: "Patient wurde ins Wartezimmer gesetzt"
      };

      res.redirect("/waiting-room");
    }
  );
}

function deactivatePatient(req, res) {
  const id = req.params.id;

  db.query(
    "UPDATE patients SET active = 0 WHERE id = ?",
    [id],
    err => {
      if (err) {
        console.error(err);
        req.session.flash = {
          type: "danger",
          message: "Patient konnte nicht gesperrt werden"
        };
        return res.redirect("/patients");
      }

      req.session.flash = {
        type: "success",
        message: "Patient wurde gesperrt"
      };

      res.redirect("/patients");
    }
  );
}

function activatePatient(req, res) {
  const id = req.params.id;

  db.query(
    "UPDATE patients SET active = 1 WHERE id = ?",
    [id],
    err => {
      if (err) {
        console.error(err);
        req.session.flash = {
          type: "danger",
          message: "Patient konnte nicht entsperrt werden"
        };
        return res.redirect("/patients");
      }

      req.session.flash = {
        type: "success",
        message: "Patient wurde entsperrt"
      };

      res.redirect("/patients");
    }
  );
}


module.exports = {
  listPatients,
  showCreatePatient,
  createPatient,
  showEditPatient,
  updatePatient,
  showPatientMedications,
  moveToWaitingRoom,
  showWaitingRoom,
  showPatientOverview,
  addPatientNote,
  callFromWaitingRoom,
  dischargePatient,
  showMedicationPlan,
  movePatientToWaitingRoom,
  deactivatePatient,
  activatePatient
};