books/backend/Books.Api/Database/Migrations/007b_JournalEntryDraftCompliance.sql

-- Migration: 007_JournalEntryDraftCompliance
-- Description: Add Danish accounting law compliance fields to journal entry drafts
-- - VoucherNumber (Bilagsnummer) - required by Bogføringsloven § 7, Stk. 4
-- - AttachmentIds - for document references required by Bogføringsloven § 6
-- - DocumentDate (Bilagsdato) - renamed from generic "date" for clarity
-- - Voucher sequence table for auto-generation of bilagsnumre

-- Add voucher_number column to existing table
ALTER TABLE journal_entry_draft_read_models
    ADD COLUMN IF NOT EXISTS voucher_number TEXT NOT NULL DEFAULT '';

-- Add attachment_ids column (JSON array of references)
ALTER TABLE journal_entry_draft_read_models
    ADD COLUMN IF NOT EXISTS attachment_ids TEXT NOT NULL DEFAULT '[]';

-- Rename date column to document_date (Bilagsdato) for semantic clarity
-- document_date = the date on the source document (e.g., invoice date)
-- This is different from posting_date which is when it's booked in the ledger
ALTER TABLE journal_entry_draft_read_models
    RENAME COLUMN date TO document_date;

-- Create voucher number sequence table per company/fiscal year
-- This ensures unique, sequential bilagsnumre as required by law
CREATE TABLE IF NOT EXISTS voucher_number_sequences (
    company_id TEXT NOT NULL,
    fiscal_year_id TEXT NOT NULL,
    last_number INT NOT NULL DEFAULT 0,
    prefix TEXT NOT NULL DEFAULT '',
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    PRIMARY KEY (company_id, fiscal_year_id)
);

-- Index for efficient lookup
CREATE INDEX IF NOT EXISTS idx_voucher_sequence_company
    ON voucher_number_sequences(company_id);

-- Index for efficient queries by voucher number
CREATE INDEX IF NOT EXISTS idx_journal_entry_draft_voucher
    ON journal_entry_draft_read_models(company_id, voucher_number);

COMMENT ON TABLE voucher_number_sequences IS 'Sequence generator for bilagsnumre (voucher numbers) per company and fiscal year';
COMMENT ON COLUMN voucher_number_sequences.prefix IS 'Optional prefix for voucher numbers, e.g. "2025-" for year-based numbering';
COMMENT ON COLUMN journal_entry_draft_read_models.voucher_number IS 'Bilagsnummer - unique document number required by Bogføringsloven § 7, Stk. 4';
COMMENT ON COLUMN journal_entry_draft_read_models.attachment_ids IS 'JSON array of attachment IDs for document references required by Bogføringsloven § 6';