-- Deduplicate seen registry by partnumber only and enforce unique partnumber key.
-- Note: MariaDB unique index on VARCHAR can treat trailing spaces as equal, so normalize first.

UPDATE qt_vendor_partnumber_seen
SET partnumber = RTRIM(partnumber)
WHERE partnumber <> RTRIM(partnumber);

CREATE TEMPORARY TABLE tmp_qt_seen_keep AS
SELECT
    LOWER(TRIM(partnumber)) AS partnumber_key,
    CAST(SUBSTRING_INDEX(
        GROUP_CONCAT(
            id
            ORDER BY
                (TRIM(COALESCE(vendor, '')) <> '') DESC,
                (source_type = 'stock') DESC,
                (is_ignored = 1) DESC,
                last_seen_at DESC,
                id DESC
            SEPARATOR ','
        ),
        ',',
        1
    ) AS UNSIGNED) AS keep_id,
    MAX(source_type = 'stock') AS has_stock,
    MAX(is_ignored) AS any_ignored,
    MAX(last_seen_at) AS max_last_seen,
    MAX(CASE WHEN is_ignored = 1 THEN ignored_at END) AS max_ignored_at,
    SUBSTRING_INDEX(
        GROUP_CONCAT(
            CASE
                WHEN is_ignored = 1 AND NULLIF(TRIM(ignored_by), '') IS NOT NULL THEN ignored_by
                ELSE NULL
            END
            ORDER BY ignored_at DESC, updated_at DESC, id DESC
            SEPARATOR '\n'
        ),
        '\n',
        1
    ) AS keep_ignored_by,
    SUBSTRING_INDEX(
        GROUP_CONCAT(
            NULLIF(TRIM(description), '')
            ORDER BY
                (source_type = 'stock') DESC,
                (TRIM(COALESCE(vendor, '')) <> '') DESC,
                last_seen_at DESC,
                id DESC
            SEPARATOR '\n'
        ),
        '\n',
        1
    ) AS keep_description,
    SUBSTRING_INDEX(
        GROUP_CONCAT(
            NULLIF(TRIM(vendor), '')
            ORDER BY
                (source_type = 'stock') DESC,
                last_seen_at DESC,
                id DESC
            SEPARATOR '\n'
        ),
        '\n',
        1
    ) AS keep_vendor
FROM qt_vendor_partnumber_seen
WHERE TRIM(COALESCE(partnumber, '')) <> ''
GROUP BY LOWER(TRIM(partnumber));

UPDATE qt_vendor_partnumber_seen s
JOIN tmp_qt_seen_keep k ON s.id = k.keep_id
SET
    s.source_type = CASE WHEN k.has_stock = 1 THEN 'stock' ELSE 'manual' END,
    s.vendor = COALESCE(NULLIF(TRIM(s.vendor), ''), NULLIF(TRIM(k.keep_vendor), ''), ''),
    s.partnumber = TRIM(s.partnumber),
    s.description = COALESCE(NULLIF(TRIM(s.description), ''), NULLIF(TRIM(k.keep_description), ''), s.description),
    s.last_seen_at = GREATEST(s.last_seen_at, k.max_last_seen),
    s.is_ignored = k.any_ignored,
    s.ignored_at = CASE
                     WHEN k.any_ignored = 1 THEN COALESCE(s.ignored_at, k.max_ignored_at)
                     ELSE NULL
                   END,
    s.ignored_by = CASE
                     WHEN k.any_ignored = 1 THEN COALESCE(NULLIF(TRIM(s.ignored_by), ''), NULLIF(TRIM(k.keep_ignored_by), ''))
                     ELSE NULL
                   END;

DELETE s
FROM qt_vendor_partnumber_seen s
LEFT JOIN tmp_qt_seen_keep k ON LOWER(TRIM(s.partnumber)) = k.partnumber_key
WHERE k.keep_id IS NULL OR s.id <> k.keep_id;

DROP TEMPORARY TABLE IF EXISTS tmp_qt_seen_keep;

-- Safety pass: remove any remaining duplicates by normalized partnumber key.
DELETE s1
FROM qt_vendor_partnumber_seen s1
INNER JOIN qt_vendor_partnumber_seen s2
    ON LOWER(TRIM(s1.partnumber)) = LOWER(TRIM(s2.partnumber))
   AND s1.id < s2.id;

SET @seen_idx_old_exists := (
    SELECT COUNT(*)
    FROM information_schema.statistics
    WHERE table_schema = DATABASE()
      AND table_name = 'qt_vendor_partnumber_seen'
      AND index_name = 'uq_qt_vendor_partnumber_seen_source_key'
);
SET @seen_idx_old_sql := IF(
    @seen_idx_old_exists > 0,
    'ALTER TABLE qt_vendor_partnumber_seen DROP INDEX uq_qt_vendor_partnumber_seen_source_key',
    'SELECT 1'
);
PREPARE stmt_seen_idx_old FROM @seen_idx_old_sql;
EXECUTE stmt_seen_idx_old;
DEALLOCATE PREPARE stmt_seen_idx_old;

SET @seen_idx_new_exists := (
    SELECT COUNT(*)
    FROM information_schema.statistics
    WHERE table_schema = DATABASE()
      AND table_name = 'qt_vendor_partnumber_seen'
      AND index_name = 'uq_qt_vendor_partnumber_seen_partnumber'
);
SET @seen_idx_new_sql := IF(
    @seen_idx_new_exists > 0,
    'SELECT 1',
    'ALTER TABLE qt_vendor_partnumber_seen ADD UNIQUE INDEX uq_qt_vendor_partnumber_seen_partnumber (partnumber)'
);
PREPARE stmt_seen_idx_new FROM @seen_idx_new_sql;
EXECUTE stmt_seen_idx_new;
DEALLOCATE PREPARE stmt_seen_idx_new;