-- Migration 042: Universal CSV Parser – Mapping-Registry & Import-Log (Issue #21)
-- Tabellen für System-Templates (profile_id NULL, is_system true) und User-Mappings.

CREATE TABLE IF NOT EXISTS csv_field_mappings (
    id SERIAL PRIMARY KEY,
    profile_id UUID REFERENCES profiles(id) ON DELETE CASCADE,
    is_system BOOLEAN NOT NULL DEFAULT false,
    module VARCHAR(50) NOT NULL,
    mapping_name VARCHAR(100) NOT NULL,
    description TEXT,
    column_signature TEXT[] NOT NULL DEFAULT '{}',
    delimiter VARCHAR(10) NOT NULL DEFAULT ',',
    encoding VARCHAR(20) NOT NULL DEFAULT 'utf-8',
    has_header BOOLEAN NOT NULL DEFAULT true,
    field_mappings JSONB NOT NULL DEFAULT '{}',
    type_conversions JSONB,
    usage_count INTEGER NOT NULL DEFAULT 0,
    last_used_at TIMESTAMPTZ,
    success_rate REAL NOT NULL DEFAULT 1.0,
    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
    CONSTRAINT csv_field_mappings_system_profile CHECK (
        (is_system = true AND profile_id IS NULL)
        OR (is_system = false AND profile_id IS NOT NULL)
    )
);

COMMENT ON TABLE csv_field_mappings IS 'CSV Import: System-Templates + User-Mappings (Issue #21)';
COMMENT ON COLUMN csv_field_mappings.is_system IS 'true = globales Template (nur Admin pflegbar), false = User-Mapping';

CREATE UNIQUE INDEX IF NOT EXISTS idx_csv_field_mappings_system_module_name
    ON csv_field_mappings (module, mapping_name)
    WHERE is_system = true AND profile_id IS NULL;

CREATE UNIQUE INDEX IF NOT EXISTS idx_csv_field_mappings_user_module_name
    ON csv_field_mappings (profile_id, module, mapping_name)
    WHERE is_system = false;

CREATE INDEX IF NOT EXISTS idx_csv_field_mappings_module_profile
    ON csv_field_mappings (module, profile_id);

CREATE INDEX IF NOT EXISTS idx_csv_field_mappings_system_module
    ON csv_field_mappings (module)
    WHERE is_system = true;

CREATE TABLE IF NOT EXISTS csv_import_log (
    id SERIAL PRIMARY KEY,
    profile_id UUID NOT NULL REFERENCES profiles(id) ON DELETE CASCADE,
    mapping_id INTEGER REFERENCES csv_field_mappings(id) ON DELETE SET NULL,
    module VARCHAR(50) NOT NULL,
    filename VARCHAR(255),
    rows_total INTEGER,
    rows_imported INTEGER,
    rows_updated INTEGER,
    rows_skipped INTEGER,
    rows_errors INTEGER,
    error_details JSONB,
    started_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
    finished_at TIMESTAMPTZ,
    status VARCHAR(20) NOT NULL DEFAULT 'running',
    affected_ids JSONB
);

CREATE INDEX IF NOT EXISTS idx_csv_import_log_profile_module
    ON csv_import_log (profile_id, module DESC, started_at DESC);

COMMENT ON COLUMN csv_import_log.affected_ids IS 'Pro Import gesammelte Primärschlüssel je Tabelle (Rollback / Bereinigung)';

INSERT INTO system_config (key, value, updated_at)
VALUES (
    'csv_import',
    '{"max_rows_per_file": 50000, "max_file_bytes": 52428800}'::jsonb,
    CURRENT_TIMESTAMP
)
ON CONFLICT (key) DO NOTHING;