-- Resolve stat_series.territory ↔ domrf_regions.region_name name mismatches.
-- Stat_series uses Rosstat-style names that differ in 18 of 99 territories:
--   • 9 regions: "г. Москва" vs "Город Москва", "Республика Адыгея (Адыгея)"
--     vs "Республика Адыгея", "- Алания"/"(Татарстан)"/"- Чувашия" suffixes;
--   • 8 federal districts ("Центральный ФО") — not in domrf_regions at all;
--   • 1 synthetic row "Российская Федерация (без г. Москва)";
--   • 2 noise rows '-' and 'г. Москва1' (XLSX parser artefacts).
--
-- Solution: an alias lookup that maps any incoming text to a structured target
-- (level + region_id|fo_id). View v_stat_series_resolved joins observations
-- through it for clean territory resolution without rewriting 809K rows.

BEGIN;

-- ── 1. Federal districts as a first-class table ─────────────────────────────
CREATE TABLE IF NOT EXISTS domrf_federal_districts (
    fo_id    INT  PRIMARY KEY,
    fo_name  TEXT NOT NULL UNIQUE
);
INSERT INTO domrf_federal_districts (fo_id, fo_name) VALUES
    (1, 'Центральный ФО'),
    (2, 'Северо-Западный ФО'),
    (3, 'Южный ФО'),
    (4, 'Северо-Кавказский ФО'),
    (5, 'Приволжский ФО'),
    (6, 'Уральский ФО'),
    (7, 'Сибирский ФО'),
    (8, 'Дальневосточный ФО')
ON CONFLICT (fo_id) DO NOTHING;

COMMENT ON TABLE domrf_federal_districts IS
    '8 федеральных округов РФ. Связывается с domrf_regions.federal_district по имени, и используется как target для domrf_territory_aliases (level=fo).';

-- ── 2. Generic territory alias table ────────────────────────────────────────
CREATE TABLE IF NOT EXISTS domrf_territory_aliases (
    territory_text   TEXT PRIMARY KEY,
    level            TEXT NOT NULL CHECK (level IN ('rf','fo','region','synthetic','noise')),
    region_id        INT  REFERENCES domrf_regions(region_id),
    fo_id            INT  REFERENCES domrf_federal_districts(fo_id),
    canonical_name   TEXT NOT NULL,
    notes            TEXT,
    CONSTRAINT alias_target_chk CHECK (
        (level='rf'        AND region_id=0          AND fo_id IS NULL) OR
        (level='region'    AND region_id IS NOT NULL AND fo_id IS NULL) OR
        (level='fo'        AND region_id IS NULL    AND fo_id IS NOT NULL) OR
        (level='synthetic' AND region_id IS NULL    AND fo_id IS NULL) OR
        (level='noise'     AND region_id IS NULL    AND fo_id IS NULL)
    )
);
CREATE INDEX IF NOT EXISTS idx_territory_aliases_region ON domrf_territory_aliases (region_id);
CREATE INDEX IF NOT EXISTS idx_territory_aliases_fo     ON domrf_territory_aliases (fo_id);

COMMENT ON TABLE domrf_territory_aliases IS
    'Text→(level, region_id|fo_id) lookup. Resolves stat_series territory naming variants to canonical regions/FO. Use v_stat_series_resolved for joined views.';

-- ── 3a. Auto-populate identity aliases for the 81 regions whose names match ─
--     (and the RF row at region_id=0)
INSERT INTO domrf_territory_aliases (territory_text, level, region_id, canonical_name, notes)
SELECT
    r.region_name,
    CASE WHEN r.region_id = 0 THEN 'rf' ELSE 'region' END,
    r.region_id,
    r.region_name,
    'auto: identity alias from domrf_regions.region_name'
FROM domrf_regions r
WHERE r.region_name IN (SELECT DISTINCT territory FROM domrf_stat_series_observations)
ON CONFLICT (territory_text) DO NOTHING;

-- ── 3b. Manual aliases for 9 regions with format differences ────────────────
INSERT INTO domrf_territory_aliases (territory_text, level, region_id, canonical_name, notes) VALUES
    ('г. Москва',                              'region', 77, 'Город Москва',                'г./Город prefix mismatch'),
    ('г. Санкт-Петербург',                     'region', 78, 'Город Санкт-Петербург',       'г./Город prefix mismatch'),
    ('г. Севастополь',                         'region', 92, 'Город Севастополь',           'г./Город prefix mismatch'),
    ('Республика Адыгея (Адыгея)',             'region',  1, 'Республика Адыгея',           'parenthetical suffix in Rosstat naming'),
    ('Республика Татарстан (Татарстан)',       'region', 16, 'Республика Татарстан',        'parenthetical suffix in Rosstat naming'),
    ('Республика Северная Осетия - Алания',    'region', 15, 'Республика Северная Осетия',  '- Алания suffix in Rosstat naming'),
    ('Чувашская Республика - Чувашия',         'region', 21, 'Чувашская Республика',        '- Чувашия suffix in Rosstat naming')
ON CONFLICT (territory_text) DO NOTHING;
-- Note: "Республика Саха (Якутия)" and "Кемеровская область - Кузбасс" use the
-- same parenthetical convention BUT match exactly between sources, so identity
-- aliases above already cover them.

-- ── 3c. Federal districts — 8 aliases pointing at the new FO table ──────────
INSERT INTO domrf_territory_aliases (territory_text, level, fo_id, canonical_name, notes)
SELECT fo_name, 'fo', fo_id, fo_name, 'auto: identity alias from domrf_federal_districts'
FROM domrf_federal_districts
ON CONFLICT (territory_text) DO NOTHING;

-- ── 3d. Synthetic + noise rows ──────────────────────────────────────────────
INSERT INTO domrf_territory_aliases (territory_text, level, canonical_name, notes) VALUES
    ('Российская Федерация (без г. Москва)', 'synthetic', 'РФ без Москвы',
     'Synthetic row in some XLSX summaries — RF totals excluding Moscow.'),
    ('-',          'noise', '-',         'XLSX parser artefact: empty separator row swallowed by parser.'),
    ('г. Москва1', 'noise', 'г. Москва1','XLSX source typo (extra "1" suffix). Real "г. Москва" present separately.')
ON CONFLICT (territory_text) DO NOTHING;

-- ── 4. Resolved view: stat_series_observations + alias target ───────────────
CREATE OR REPLACE VIEW v_stat_series_resolved AS
SELECT
    o.snapshot_date,
    o.file_name,
    o.sheet_code,
    i.indicator_name,
    o.territory,
    a.level         AS territory_level,
    a.region_id,
    a.fo_id,
    a.canonical_name,
    o.obs_date,
    o.value
FROM domrf_stat_series_observations o
LEFT JOIN domrf_territory_aliases a
       ON a.territory_text = o.territory
LEFT JOIN domrf_stat_series_indicators i
       ON i.file_name = o.file_name AND i.sheet_code = o.sheet_code;

COMMENT ON VIEW v_stat_series_resolved IS
    'stat_series_observations + indicator name + resolved territory (level/region_id/fo_id). Filter WHERE territory_level=''region'' for clean region-level analysis.';

COMMIT;