-- Rechnungen: Entwurf ist frei änderbar, ab "Ausstellen" unveränderlich (nur per Storno korrigierbar,
-- niemals nachträglich bearbeitet oder gelöscht – siehe docs/rechnungen.md).
CREATE TABLE company_settings (
  id TINYINT PRIMARY KEY DEFAULT 1,
  name VARCHAR(200) NULL, street VARCHAR(200) NULL, zip VARCHAR(20) NULL, city VARCHAR(100) NULL, country CHAR(2) NULL DEFAULT 'DE',
  tax_number VARCHAR(50) NULL,      -- Steuernummer
  vat_id VARCHAR(30) NULL,          -- USt-IdNr.
  bank_name VARCHAR(150) NULL, iban VARCHAR(34) NULL, bic VARCHAR(11) NULL,
  invoice_prefix VARCHAR(10) NOT NULL DEFAULT 'RE',
  default_due_days INT NOT NULL DEFAULT 14,
  payment_methods JSON NOT NULL DEFAULT (JSON_ARRAY('Überweisung')),
  footer_text VARCHAR(500) NULL,
  updated_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) ON UPDATE CURRENT_TIMESTAMP(3)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
INSERT INTO company_settings (id) VALUES (1);
INSERT INTO number_sequences (name, next_value) VALUES ('invoice', 1000) ON DUPLICATE KEY UPDATE name = name;

CREATE TABLE invoices (
  id CHAR(36) PRIMARY KEY,
  number VARCHAR(30) NULL UNIQUE,     -- erst ab "Ausstellen" vergeben; Entwurf hat keine Nummer
  org_id CHAR(36) NOT NULL REFERENCES organizations(id),
  status ENUM('draft','open','paid','cancelled') NOT NULL DEFAULT 'draft',
  issue_date DATE NULL,
  due_date DATE NULL,
  currency CHAR(3) NOT NULL DEFAULT 'EUR',
  total_net_cents INT NOT NULL DEFAULT 0,
  total_tax_cents INT NOT NULL DEFAULT 0,
  total_gross_cents INT NOT NULL DEFAULT 0,
  payment_method VARCHAR(50) NULL,
  note VARCHAR(500) NULL,
  paid_at DATETIME(3) NULL,
  cancels_invoice_id CHAR(36) NULL REFERENCES invoices(id),  -- gesetzt bei einer Stornorechnung (negative Beträge)
  cancelled_by_invoice_id CHAR(36) NULL REFERENCES invoices(id), -- Rückverweis von der stornierten Rechnung auf ihr Storno
  created_by CHAR(36) NOT NULL REFERENCES users(id),
  created_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
  issued_at DATETIME(3) NULL,
  cancelled_at DATETIME(3) NULL,
  KEY idx_inv_org (org_id), KEY idx_inv_status (status)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE invoice_items (
  id CHAR(36) PRIMARY KEY,
  invoice_id CHAR(36) NOT NULL REFERENCES invoices(id),
  contract_id CHAR(36) NULL REFERENCES contracts(id),
  description VARCHAR(300) NOT NULL,
  quantity DECIMAL(10,2) NOT NULL DEFAULT 1,
  unit_price_net_cents INT NOT NULL,
  tax_bp INT NOT NULL,
  net_cents INT NOT NULL,
  tax_cents INT NOT NULL,
  gross_cents INT NOT NULL,
  sort_order INT NOT NULL DEFAULT 0,
  KEY idx_ii_invoice (invoice_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;