-- =====================================================================
-- 44_document.sql
-- Documents
--
-- GENERATED by _gen/pack.py from ../step/. DO NOT EDIT -- edit the source
-- there and re-pack, or the sha256 in MANIFEST.md stops matching.
--
-- 3 table(s), 12 ledger step(s).
--
-- ⚠ IMPORT ORDER: 01_system.sql, then all seven 1x masters, then this file. Order among
--    transactions does not matter. Re-importing costs nothing.
--
-- ⚠ STOP ON THE FIRST ERROR. Do not use `mysql --force`, and do not tick any
--    "continue on error" box. Each step records itself in `_migration_ledger`
--    immediately after its statement runs, WITHOUT checking that the statement
--    succeeded -- that is inherited from step/, where run.sh guarantees a stop by
--    running mysql without --force. Continue past an error here and a step that
--    failed is marked applied: 99_finalize.sql will then seed `migrations`, and
--    `php artisan migrate` will skip the work still owed. Both default clients
--    stop on error; the danger is turning that off.
--
-- ⚠ phpMyAdmin: UNTICK "Allow the interruption of an import".
--    If it fires, the import resumes on a NEW CONNECTION: SQL_MODE reverts to the server
--    default and every @variable dies, mid-file. Two things then break. NO_ZERO_DATE is
--    back, so any ALTER that rebuilds a table holding '0000-00-00' fails with ERROR 1292.
--    And @step / @todo / @sql are NULL, so the guard around the next payload stops meaning
--    anything. The SET SQL_MODE before every unit below limits the damage when someone
--    forgets the checkbox; it does not replace unticking it.
--
--    (STRICT_TRANS_TABLES is forced for a third case -- a value too big for its new column
--    is CLAMPED silently rather than refused. Measured on the tree as it stands, no column
--    narrows: all 674 MODIFY COLUMNs widen or are no-ops. It stays forced because the next
--    regeneration is under no obligation to keep that true.)
--
-- ⚠ Take a full backup first. The `20_cleanup` steps change data and nothing here
--    reverses them. `../audit_bukanmain_before_migrate.sql` only reads.
-- =====================================================================

-- Menus this file serves (5 links):
--   /documents/internal
--   /documents/internal/download
--   /documents/principal
--   /documents/principal/download
--   /documents/principal/download-all

-- --------------------------------------------------------------- prologue
-- run.sh sources step/_lib/session.sql for you. phpMyAdmin will not, so it is inlined.
             AND @@SQL_MODE LIKE '%NO_AUTO_VALUE_ON_ZERO%'
             AND @@SQL_MODE NOT LIKE '%NO_ZERO_DATE%'
             AND @@SQL_MODE NOT LIKE '%NO_ZERO_IN_DATE%',
        @@SQL_MODE,
        CONCAT(REPLACE(REPLACE(@@SQL_MODE, 'NO_ZERO_IN_DATE', ''), 'NO_ZERO_DATE', ''),
               ',NO_AUTO_VALUE_ON_ZERO,STRICT_TRANS_TABLES'));
-- Assert all four, not just the first. STRICT_TRANS_TABLES missing means out-of-range
-- values are clamped silently; NO_ZERO_DATE still present means any ALTER that rebuilds a
-- legacy table re-validates its '0000-00-00' rows and dies with ERROR 1292. The second is
-- the one that actually stops the migration, and it was not being checked.
SELECT IF(@@SQL_MODE LIKE '%STRICT_TRANS_TABLES%'
      AND @@SQL_MODE LIKE '%NO_AUTO_VALUE_ON_ZERO%'
      AND @@SQL_MODE NOT LIKE '%NO_ZERO_DATE%'
      AND @@SQL_MODE NOT LIKE '%NO_ZERO_IN_DATE%',
          'sql_mode OK - proceeding',
          (SELECT 'ABORT: sql_mode is wrong. Wanted STRICT_TRANS_TABLES + NO_AUTO_VALUE_ON_ZERO,'
           UNION ALL
           SELECT 'and NO_ZERO_DATE / NO_ZERO_IN_DATE OFF. The SET above should have done it.')
       ) AS preflight_sql_mode;

SET SESSION lock_wait_timeout = 60;
SET SESSION innodb_lock_wait_timeout = 60;

-- The ledger, copied verbatim from step/_lib/ledger.sql -- not restated, so the two
-- paths cannot disagree about its definition.
-- ---------------------------------------------------------------------
-- _lib/ledger.sql  --  the only thing here that is not in the source file
-- One row per applied step. This is the record that decides what a re-run skips,
-- what --status reports, and -- through the app-side gate -- which modules the
-- application will serve. It lives in the database on purpose: a file on one
-- operator's laptop drifts the moment someone runs a step from another machine.
--
-- Deliberately NOT in the project's PascalCase convention. It is an ops table, never
-- touched by Eloquent, and it should be visibly not-an-app-table.
--
-- `checksum` is the SHA-256 of the step's SQL payload -- the verbatim statements,
-- not the file -- so it cannot change when a comment above them is reworded.
-- _lib/steps.tsv carries the whole-file hashes for tamper detection.
--
-- ⚠ `step` IS ascii, AND THAT IS LOAD-BEARING. Every guard compares it against a
-- user variable, and a user variable carries the CONNECTION collation. Give this
-- column utf8mb4_unicode_ci and the very first step dies with ERROR 1267,
-- "Illegal mix of collations (utf8mb4_unicode_ci,IMPLICIT) and
-- (utf8mb4_0900_ai_ci,IMPLICIT) for operation '='" -- measured, that is exactly
-- how the first end-to-end run failed. ascii is a repertoire subset of latin1 and
-- of utf8mb4, so the server coerces it to whatever the connection is using,
-- whatever that turns out to be on the day. Step names are [a-z0-9_/] by
-- construction, so nothing is lost.
-- ---------------------------------------------------------------------

CREATE TABLE IF NOT EXISTS `_migration_ledger` (
  `step`        varchar(191) CHARACTER SET ascii COLLATE ascii_general_ci NOT NULL,
  `applied_at`  datetime     NOT NULL,
  `checksum`    char(64)     NOT NULL,
  `duration_ms` int          NOT NULL,
  PRIMARY KEY (`step`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;


-- --------------------------------------------------------------- preflight
-- 00_system/01_system.sql MUST already be applied. Every doc says so; until now nothing
-- enforced it, and the violation was silent for most of the tree: only three files break
-- without it (30_quotation and 40_budgetandtarget hit ERROR 1146 on a table 01_system
-- creates, and 99_finalize needs `migrations`). The other twenty import cleanly, record
-- their ledger rows, and leave a database that is half-migrated with nothing to say so.
--
-- 13 steps: the ALTER DATABASE plus the 12 CREATE TABLEs.
SET @sys_done = (SELECT COUNT(*) FROM `_migration_ledger` WHERE `step` LIKE '\_system/%');
SET @pf_sys = IF(@sys_done >= 13,
    'SELECT ''preflight: 00_system is applied'' AS preflight_system',
    'SELECT `ABORT: import 00_system/01_system.sql first. It runs the ALTER DATABASE and creates the 12 new tables that everything here assumes exist.`');
PREPARE _pf FROM @pf_sys; EXECUTE _pf; DEALLOCATE PREPARE _pf;

-- --------------------------------------------------------------- preflight
-- WAS THIS DATABASE MIGRATED FROM A DIFFERENT VERSION OF THIS FILE?
--
-- `_migration_ledger.checksum` is the SHA-256 of each step's payload. It is written 632
-- times across the tree and, until this block existed, read never -- so a corrected payload
-- re-issued under the same step name was skipped forever on any database that had recorded
-- the old one, silently and permanently.
SELECT COUNT(*) INTO @ck_bad FROM `_migration_ledger`
 WHERE `step` IN ('documentgroupdivision/10_alter', 'documentgroupdivision/20_cleanup', 'documentgroupdivision/30_assert', 'documentgroupdivision/40_fk', 'documentupload/10_alter', 'documentupload/20_cleanup', 'documentupload/30_assert', 'documentupload/40_fk', 'documentuploadinternal/10_alter', 'documentuploadinternal/20_cleanup', 'documentuploadinternal/30_assert', 'documentuploadinternal/40_fk')
   AND CONCAT(`step`, ':', `checksum`) NOT IN ('documentgroupdivision/10_alter:30f81b8b051133baacdfe0d65c7eedc018e8a9e963a6f71e53e92ca31107c8a0', 'documentgroupdivision/20_cleanup:1cb229dff80ccd8b1e2364636185a83378080ad4f88bfcdfa8cf3e838634d408', 'documentgroupdivision/30_assert:ecc01e1f012e1a03b9ccc017d70dc63a9ab4f17ece589cd3aa6729d448a72ce8', 'documentgroupdivision/40_fk:e92125e196ec473945d7a5b18d54ca3f5b2665e1d0e8bb5f40004ec048483008', 'documentupload/10_alter:5a1507cf3dca1be6c45c3a17d0f900f32e1b03e1f7ced0e3081842e2d049d564', 'documentupload/20_cleanup:5f07858e8f27e922926a1328212321700a0a37e3c1b9213b01ebc2e3459979e8', 'documentupload/30_assert:6cfb65f361afbc673af37d832a7fc584aaa0c8c7a182cec4f6b60c7b404b3be1', 'documentupload/40_fk:915a7e63c6ca2112cc04b63e67bcf0fcfa33fdde532259e1e802fc141a7b87aa', 'documentuploadinternal/10_alter:87fe757474cd73d7c780adeaf48a5e5ac1bc9e6279a9235981f81b3a2a0584c5', 'documentuploadinternal/20_cleanup:c03611a668d386841b200ac63eb43190aad50d07ce21eb3f7763589f4f1104d6', 'documentuploadinternal/30_assert:9f17bcabff1e3dc58684bea966648b0b8ce270bbbbc9b49c16103654448a49b2', 'documentuploadinternal/40_fk:b4432cd0b68a26bf225dc8572b26ed15501066a485c7f850695093bcd5c0671a');
SET @pf_ck = IF(@ck_bad = 0,
    'SELECT ''preflight: ledger matches this file'' AS preflight_checksum',
    CONCAT('SELECT `ABORT: ', @ck_bad, ' step(s) here were applied from a DIFFERENT version of this file. Their payloads changed. Compare before re-importing; do not delete ledger rows blindly.`'));
PREPARE _pf FROM @pf_ck; EXECUTE _pf; DEALLOCATE PREPARE _pf;

-- ---------------------------------------------------------------------
-- unit: documentupload    (transaction)
-- ---------------------------------------------------------------------
             AND @@SQL_MODE LIKE '%NO_AUTO_VALUE_ON_ZERO%'
             AND @@SQL_MODE NOT LIKE '%NO_ZERO_DATE%'
             AND @@SQL_MODE NOT LIKE '%NO_ZERO_IN_DATE%',
        @@SQL_MODE,
        CONCAT(REPLACE(REPLACE(@@SQL_MODE, 'NO_ZERO_IN_DATE', ''), 'NO_ZERO_DATE', ''),
               ',NO_AUTO_VALUE_ON_ZERO,STRICT_TRANS_TABLES'));
-- ---------------------------------------------------------------------
-- documentupload/10_alter  --  source section A
-- The merged ALTER: new columns, type/charset changes, column order, NULL relaxation
-- and the indexes every foreign key needs -- ONE statement, so InnoDB rebuilds this
-- table ONCE. The original migration split these across five sections and rebuilt some
-- tables four times; that is where its 12 hours went. Do not split this back up.
--
-- Clause order is the original section order (3b, 3d, 3e, 4, 7), which is what keeps
-- every ADD COLUMN ... AFTER positioned exactly as before.
-- ---------------------------------------------------------------------

SET @step = 'documentupload/10_alter';
SET @todo = (SELECT COUNT(*) = 0 FROM `_migration_ledger` WHERE `step` = @step);
SET @t0 = NOW(3);
SET @sql = IF(@todo, 'ALTER TABLE `documentupload`
  MODIFY COLUMN `PrincipalID` int DEFAULT NULL,
  MODIFY COLUMN `DocumentCategoryID` int DEFAULT NULL,
  ADD INDEX `documentupload_DocumentCategoryID` (`DocumentCategoryID`),
  ADD INDEX `PrincipalID` (`PrincipalID`,`DocumentCategoryID`)', 'DO 0');
PREPARE _step FROM @sql; EXECUTE _step; DEALLOCATE PREPARE _step;
INSERT INTO `_migration_ledger` (`step`, `applied_at`, `checksum`, `duration_ms`)
     VALUES (@step, NOW(), '5a1507cf3dca1be6c45c3a17d0f900f32e1b03e1f7ced0e3081842e2d049d564', TIMESTAMPDIFF(MICROSECOND, @t0, NOW(3)) DIV 1000)
ON DUPLICATE KEY UPDATE `step` = `step`;
-- ---------------------------------------------------------------------
-- documentupload/20_cleanup  --  source section B (= the original sections 5 and 6, merged)
-- 0-sentinels AND orphaned references -> NULL, one pass per table.
--     section 5:  WHERE `c` = 0
--     section 6:  WHERE `c` IS NOT NULL AND parent.ID IS NULL
--     merged   :  WHERE `c` IS NOT NULL AND (`c` = 0 OR parent.ID IS NULL)
-- Every LEFT JOIN is a primary-key equality, so none of them can multiply rows.
--
-- DATA CHANGE, and this script cannot reverse it. Run the audit first.
-- In its own transaction, with the ledger row inside it: either the cleanup and the
-- record of it both land, or neither does.
-- ---------------------------------------------------------------------

START TRANSACTION;

SET @step = 'documentupload/20_cleanup';
SET @todo = (SELECT COUNT(*) = 0 FROM `_migration_ledger` WHERE `step` = @step);
SET @t0 = NOW(3);
SET @sql = IF(@todo, 'UPDATE `documentupload` c
  LEFT JOIN `documentcategory` p0 ON c.`DocumentCategoryID` = p0.`ID`
  LEFT JOIN `principal` p1 ON c.`PrincipalID` = p1.`ID`
   SET
       c.`DocumentCategoryID` = IF((c.`DocumentCategoryID` IS NOT NULL AND (c.`DocumentCategoryID` = 0 OR p0.`ID` IS NULL)), NULL, c.`DocumentCategoryID`),
       c.`PrincipalID` = IF((c.`PrincipalID` IS NOT NULL AND (c.`PrincipalID` = 0 OR p1.`ID` IS NULL)), NULL, c.`PrincipalID`)
 WHERE  (c.`DocumentCategoryID` IS NOT NULL AND (c.`DocumentCategoryID` = 0 OR p0.`ID` IS NULL))
    OR (c.`PrincipalID` IS NOT NULL AND (c.`PrincipalID` = 0 OR p1.`ID` IS NULL))', 'DO 0');
PREPARE _step FROM @sql; EXECUTE _step; DEALLOCATE PREPARE _step;
INSERT INTO `_migration_ledger` (`step`, `applied_at`, `checksum`, `duration_ms`)
     VALUES (@step, NOW(), '5f07858e8f27e922926a1328212321700a0a37e3c1b9213b01ebc2e3459979e8', TIMESTAMPDIFF(MICROSECOND, @t0, NOW(3)) DIV 1000)
ON DUPLICATE KEY UPDATE `step` = `step`;

COMMIT;
-- ---------------------------------------------------------------------
-- documentupload/30_assert  --  source section 7b
-- Orphan assertion over this table's 2 foreign-key relationships.
--
-- This is what pays for 40_fk being fast. The original created the constraints with
-- FOREIGN_KEY_CHECKS ON so a row the cleanup missed would abort the run, and paid for it
-- with a full table copy per constraint. This buys the same protection with one indexed
-- pass, and 40_fk then adds the constraints as metadata only.
--
-- NOT ledger-guarded on the way in, unlike every other phase: it only reads, and the
-- point of it is to be re-runnable. It does record its ledger row -- 40_fk requires it.
--
-- IF THIS ABORTS: a row survived 20_cleanup. Same stop-and-look event the original would
-- have hit as ERROR 1452 inside section 8, but nothing has been created yet.
-- ---------------------------------------------------------------------

SET @step = 'documentupload/30_assert';
SET @t0 = NOW(3);
SET @orphans = 0;
SELECT COUNT(*) INTO @n FROM `documentupload` c
  LEFT JOIN `documentcategory` p0 ON c.`DocumentCategoryID` = p0.`ID`
  LEFT JOIN `principal` p1 ON c.`PrincipalID` = p1.`ID`
 WHERE  (c.`DocumentCategoryID` IS NOT NULL AND p0.`ID` IS NULL)
    OR (c.`PrincipalID` IS NOT NULL AND p1.`ID` IS NULL);
SET @orphans = @orphans + @n;

-- Two-row subquery on the false branch: ERROR 1242, an abort, before 40_fk runs.
SELECT IF(@orphans = 0,
          'documentupload: orphan check OK - 0 rows across 2 relationships',
          (SELECT CONCAT('ABORT: ', @orphans, ' rows in `documentupload` still reference a parent that does not exist')
           UNION ALL
           SELECT 'Run 20_cleanup for this table first. Do NOT skip this check.')
       ) AS preflight_orphans;

INSERT INTO `_migration_ledger` (`step`, `applied_at`, `checksum`, `duration_ms`)
     VALUES (@step, NOW(), '6cfb65f361afbc673af37d832a7fc584aaa0c8c7a182cec4f6b60c7b404b3be1', TIMESTAMPDIFF(MICROSECOND, @t0, NOW(3)) DIV 1000)
ON DUPLICATE KEY UPDATE `step` = `step`;
-- ---------------------------------------------------------------------
-- documentupload/40_fk  --  source section 8
-- The constraints, one ALTER for the whole table.
--
-- FOREIGN_KEY_CHECKS is turned OFF for this statement and restored afterwards. With
-- checks on InnoDB cannot add a foreign key in place -- it copies the whole table and
-- re-validates every row, which is where the original migration's 154 table copies
-- came from. The validation is not skipped, it MOVED: 30_assert proves zero orphans
-- and refuses to let this run otherwise.
-- ---------------------------------------------------------------------

SET @fk_prev = @@FOREIGN_KEY_CHECKS;

SET @step = 'documentupload/40_fk';
SET @todo = (SELECT COUNT(*) = 0 FROM `_migration_ledger` WHERE `step` = @step);
SET @t0 = NOW(3);
SET @sql = IF(@todo, 'ALTER TABLE `documentupload`
  ADD CONSTRAINT `documentupload_DocumentCategoryID` FOREIGN KEY (`DocumentCategoryID`) REFERENCES `documentcategory` (`ID`) ON DELETE RESTRICT ON UPDATE RESTRICT,
  ADD CONSTRAINT `documentupload_PrincipalID` FOREIGN KEY (`PrincipalID`) REFERENCES `principal` (`ID`) ON DELETE RESTRICT ON UPDATE RESTRICT', 'DO 0');
PREPARE _step FROM @sql; EXECUTE _step; DEALLOCATE PREPARE _step;
INSERT INTO `_migration_ledger` (`step`, `applied_at`, `checksum`, `duration_ms`)
     VALUES (@step, NOW(), '915a7e63c6ca2112cc04b63e67bcf0fcfa33fdde532259e1e802fc141a7b87aa', TIMESTAMPDIFF(MICROSECOND, @t0, NOW(3)) DIV 1000)
ON DUPLICATE KEY UPDATE `step` = `step`;


-- ---------------------------------------------------------------------
-- unit: documentgroupdivision    (detail, owned by documentupload)
-- ---------------------------------------------------------------------
             AND @@SQL_MODE LIKE '%NO_AUTO_VALUE_ON_ZERO%'
             AND @@SQL_MODE NOT LIKE '%NO_ZERO_DATE%'
             AND @@SQL_MODE NOT LIKE '%NO_ZERO_IN_DATE%',
        @@SQL_MODE,
        CONCAT(REPLACE(REPLACE(@@SQL_MODE, 'NO_ZERO_IN_DATE', ''), 'NO_ZERO_DATE', ''),
               ',NO_AUTO_VALUE_ON_ZERO,STRICT_TRANS_TABLES'));
-- ---------------------------------------------------------------------
-- documentgroupdivision/10_alter  --  source section A
-- The merged ALTER: new columns, type/charset changes, column order, NULL relaxation
-- and the indexes every foreign key needs -- ONE statement, so InnoDB rebuilds this
-- table ONCE. The original migration split these across five sections and rebuilt some
-- tables four times; that is where its 12 hours went. Do not split this back up.
--
-- Clause order is the original section order (3b, 3d, 3e, 4, 7), which is what keeps
-- every ADD COLUMN ... AFTER positioned exactly as before.
-- ---------------------------------------------------------------------

SET @step = 'documentgroupdivision/10_alter';
SET @todo = (SELECT COUNT(*) = 0 FROM `_migration_ledger` WHERE `step` = @step);
SET @t0 = NOW(3);
SET @sql = IF(@todo, 'ALTER TABLE `documentgroupdivision`
  MODIFY COLUMN `DocID` int DEFAULT NULL,
  MODIFY COLUMN `GroupDivID` int DEFAULT NULL,
  ADD INDEX `documentgroupdivision_DocID` (`DocID`),
  ADD INDEX `documentgroupdivision_GroupDivID` (`GroupDivID`)', 'DO 0');
PREPARE _step FROM @sql; EXECUTE _step; DEALLOCATE PREPARE _step;
INSERT INTO `_migration_ledger` (`step`, `applied_at`, `checksum`, `duration_ms`)
     VALUES (@step, NOW(), '30f81b8b051133baacdfe0d65c7eedc018e8a9e963a6f71e53e92ca31107c8a0', TIMESTAMPDIFF(MICROSECOND, @t0, NOW(3)) DIV 1000)
ON DUPLICATE KEY UPDATE `step` = `step`;
-- ---------------------------------------------------------------------
-- documentgroupdivision/20_cleanup  --  source section B (= the original sections 5 and 6, merged)
-- 0-sentinels AND orphaned references -> NULL, one pass per table.
--     section 5:  WHERE `c` = 0
--     section 6:  WHERE `c` IS NOT NULL AND parent.ID IS NULL
--     merged   :  WHERE `c` IS NOT NULL AND (`c` = 0 OR parent.ID IS NULL)
-- Every LEFT JOIN is a primary-key equality, so none of them can multiply rows.
--
-- DATA CHANGE, and this script cannot reverse it. Run the audit first.
-- In its own transaction, with the ledger row inside it: either the cleanup and the
-- record of it both land, or neither does.
-- ---------------------------------------------------------------------

START TRANSACTION;

SET @step = 'documentgroupdivision/20_cleanup';
SET @todo = (SELECT COUNT(*) = 0 FROM `_migration_ledger` WHERE `step` = @step);
SET @t0 = NOW(3);
SET @sql = IF(@todo, 'UPDATE `documentgroupdivision` c
  LEFT JOIN `documentupload` p0 ON c.`DocID` = p0.`ID`
  LEFT JOIN `groupdivision` p1 ON c.`GroupDivID` = p1.`ID`
   SET
       c.`DocID` = IF((c.`DocID` IS NOT NULL AND (c.`DocID` = 0 OR p0.`ID` IS NULL)), NULL, c.`DocID`),
       c.`GroupDivID` = IF((c.`GroupDivID` IS NOT NULL AND (c.`GroupDivID` = 0 OR p1.`ID` IS NULL)), NULL, c.`GroupDivID`)
 WHERE  (c.`DocID` IS NOT NULL AND (c.`DocID` = 0 OR p0.`ID` IS NULL))
    OR (c.`GroupDivID` IS NOT NULL AND (c.`GroupDivID` = 0 OR p1.`ID` IS NULL))', 'DO 0');
PREPARE _step FROM @sql; EXECUTE _step; DEALLOCATE PREPARE _step;
INSERT INTO `_migration_ledger` (`step`, `applied_at`, `checksum`, `duration_ms`)
     VALUES (@step, NOW(), '1cb229dff80ccd8b1e2364636185a83378080ad4f88bfcdfa8cf3e838634d408', TIMESTAMPDIFF(MICROSECOND, @t0, NOW(3)) DIV 1000)
ON DUPLICATE KEY UPDATE `step` = `step`;

COMMIT;
-- ---------------------------------------------------------------------
-- documentgroupdivision/30_assert  --  source section 7b
-- Orphan assertion over this table's 2 foreign-key relationships.
--
-- This is what pays for 40_fk being fast. The original created the constraints with
-- FOREIGN_KEY_CHECKS ON so a row the cleanup missed would abort the run, and paid for it
-- with a full table copy per constraint. This buys the same protection with one indexed
-- pass, and 40_fk then adds the constraints as metadata only.
--
-- NOT ledger-guarded on the way in, unlike every other phase: it only reads, and the
-- point of it is to be re-runnable. It does record its ledger row -- 40_fk requires it.
--
-- IF THIS ABORTS: a row survived 20_cleanup. Same stop-and-look event the original would
-- have hit as ERROR 1452 inside section 8, but nothing has been created yet.
-- ---------------------------------------------------------------------

SET @step = 'documentgroupdivision/30_assert';
SET @t0 = NOW(3);
SET @orphans = 0;
SELECT COUNT(*) INTO @n FROM `documentgroupdivision` c
  LEFT JOIN `documentupload` p0 ON c.`DocID` = p0.`ID`
  LEFT JOIN `groupdivision` p1 ON c.`GroupDivID` = p1.`ID`
 WHERE  (c.`DocID` IS NOT NULL AND p0.`ID` IS NULL)
    OR (c.`GroupDivID` IS NOT NULL AND p1.`ID` IS NULL);
SET @orphans = @orphans + @n;

-- Two-row subquery on the false branch: ERROR 1242, an abort, before 40_fk runs.
SELECT IF(@orphans = 0,
          'documentgroupdivision: orphan check OK - 0 rows across 2 relationships',
          (SELECT CONCAT('ABORT: ', @orphans, ' rows in `documentgroupdivision` still reference a parent that does not exist')
           UNION ALL
           SELECT 'Run 20_cleanup for this table first. Do NOT skip this check.')
       ) AS preflight_orphans;

INSERT INTO `_migration_ledger` (`step`, `applied_at`, `checksum`, `duration_ms`)
     VALUES (@step, NOW(), 'ecc01e1f012e1a03b9ccc017d70dc63a9ab4f17ece589cd3aa6729d448a72ce8', TIMESTAMPDIFF(MICROSECOND, @t0, NOW(3)) DIV 1000)
ON DUPLICATE KEY UPDATE `step` = `step`;
-- ---------------------------------------------------------------------
-- documentgroupdivision/40_fk  --  source section 8
-- The constraints, one ALTER for the whole table.
--
-- FOREIGN_KEY_CHECKS is turned OFF for this statement and restored afterwards. With
-- checks on InnoDB cannot add a foreign key in place -- it copies the whole table and
-- re-validates every row, which is where the original migration's 154 table copies
-- came from. The validation is not skipped, it MOVED: 30_assert proves zero orphans
-- and refuses to let this run otherwise.
-- ---------------------------------------------------------------------

SET @fk_prev = @@FOREIGN_KEY_CHECKS;

SET @step = 'documentgroupdivision/40_fk';
SET @todo = (SELECT COUNT(*) = 0 FROM `_migration_ledger` WHERE `step` = @step);
SET @t0 = NOW(3);
SET @sql = IF(@todo, 'ALTER TABLE `documentgroupdivision`
  ADD CONSTRAINT `documentgroupdivision_DocID` FOREIGN KEY (`DocID`) REFERENCES `documentupload` (`ID`) ON DELETE RESTRICT ON UPDATE RESTRICT,
  ADD CONSTRAINT `documentgroupdivision_GroupDivID` FOREIGN KEY (`GroupDivID`) REFERENCES `groupdivision` (`ID`) ON DELETE RESTRICT ON UPDATE RESTRICT', 'DO 0');
PREPARE _step FROM @sql; EXECUTE _step; DEALLOCATE PREPARE _step;
INSERT INTO `_migration_ledger` (`step`, `applied_at`, `checksum`, `duration_ms`)
     VALUES (@step, NOW(), 'e92125e196ec473945d7a5b18d54ca3f5b2665e1d0e8bb5f40004ec048483008', TIMESTAMPDIFF(MICROSECOND, @t0, NOW(3)) DIV 1000)
ON DUPLICATE KEY UPDATE `step` = `step`;


-- ---------------------------------------------------------------------
-- unit: documentuploadinternal    (transaction)
-- ---------------------------------------------------------------------
             AND @@SQL_MODE LIKE '%NO_AUTO_VALUE_ON_ZERO%'
             AND @@SQL_MODE NOT LIKE '%NO_ZERO_DATE%'
             AND @@SQL_MODE NOT LIKE '%NO_ZERO_IN_DATE%',
        @@SQL_MODE,
        CONCAT(REPLACE(REPLACE(@@SQL_MODE, 'NO_ZERO_IN_DATE', ''), 'NO_ZERO_DATE', ''),
               ',NO_AUTO_VALUE_ON_ZERO,STRICT_TRANS_TABLES'));
-- ---------------------------------------------------------------------
-- documentuploadinternal/10_alter  --  source section A
-- The merged ALTER: new columns, type/charset changes, column order, NULL relaxation
-- and the indexes every foreign key needs -- ONE statement, so InnoDB rebuilds this
-- table ONCE. The original migration split these across five sections and rebuilt some
-- tables four times; that is where its 12 hours went. Do not split this back up.
--
-- Clause order is the original section order (3b, 3d, 3e, 4, 7), which is what keeps
-- every ADD COLUMN ... AFTER positioned exactly as before.
-- ---------------------------------------------------------------------

SET @step = 'documentuploadinternal/10_alter';
SET @todo = (SELECT COUNT(*) = 0 FROM `_migration_ledger` WHERE `step` = @step);
SET @t0 = NOW(3);
SET @sql = IF(@todo, 'ALTER TABLE `documentuploadinternal`
  MODIFY COLUMN `DocumentCategoryID` int DEFAULT NULL,
  ADD INDEX `DocumentCategoryID` (`DocumentCategoryID`)', 'DO 0');
PREPARE _step FROM @sql; EXECUTE _step; DEALLOCATE PREPARE _step;
INSERT INTO `_migration_ledger` (`step`, `applied_at`, `checksum`, `duration_ms`)
     VALUES (@step, NOW(), '87fe757474cd73d7c780adeaf48a5e5ac1bc9e6279a9235981f81b3a2a0584c5', TIMESTAMPDIFF(MICROSECOND, @t0, NOW(3)) DIV 1000)
ON DUPLICATE KEY UPDATE `step` = `step`;
-- ---------------------------------------------------------------------
-- documentuploadinternal/20_cleanup  --  source section B (= the original sections 5 and 6, merged)
-- 0-sentinels AND orphaned references -> NULL, one pass per table.
--     section 5:  WHERE `c` = 0
--     section 6:  WHERE `c` IS NOT NULL AND parent.ID IS NULL
--     merged   :  WHERE `c` IS NOT NULL AND (`c` = 0 OR parent.ID IS NULL)
-- Every LEFT JOIN is a primary-key equality, so none of them can multiply rows.
--
-- DATA CHANGE, and this script cannot reverse it. Run the audit first.
-- In its own transaction, with the ledger row inside it: either the cleanup and the
-- record of it both land, or neither does.
-- ---------------------------------------------------------------------

START TRANSACTION;

SET @step = 'documentuploadinternal/20_cleanup';
SET @todo = (SELECT COUNT(*) = 0 FROM `_migration_ledger` WHERE `step` = @step);
SET @t0 = NOW(3);
SET @sql = IF(@todo, 'UPDATE `documentuploadinternal` c
  LEFT JOIN `documentcategory` p0 ON c.`DocumentCategoryID` = p0.`ID`
   SET
       c.`DocumentCategoryID` = IF((c.`DocumentCategoryID` IS NOT NULL AND (c.`DocumentCategoryID` = 0 OR p0.`ID` IS NULL)), NULL, c.`DocumentCategoryID`)
 WHERE  (c.`DocumentCategoryID` IS NOT NULL AND (c.`DocumentCategoryID` = 0 OR p0.`ID` IS NULL))', 'DO 0');
PREPARE _step FROM @sql; EXECUTE _step; DEALLOCATE PREPARE _step;
INSERT INTO `_migration_ledger` (`step`, `applied_at`, `checksum`, `duration_ms`)
     VALUES (@step, NOW(), 'c03611a668d386841b200ac63eb43190aad50d07ce21eb3f7763589f4f1104d6', TIMESTAMPDIFF(MICROSECOND, @t0, NOW(3)) DIV 1000)
ON DUPLICATE KEY UPDATE `step` = `step`;

COMMIT;
-- ---------------------------------------------------------------------
-- documentuploadinternal/30_assert  --  source section 7b
-- Orphan assertion over this table's 1 foreign-key relationships.
--
-- This is what pays for 40_fk being fast. The original created the constraints with
-- FOREIGN_KEY_CHECKS ON so a row the cleanup missed would abort the run, and paid for it
-- with a full table copy per constraint. This buys the same protection with one indexed
-- pass, and 40_fk then adds the constraints as metadata only.
--
-- NOT ledger-guarded on the way in, unlike every other phase: it only reads, and the
-- point of it is to be re-runnable. It does record its ledger row -- 40_fk requires it.
--
-- IF THIS ABORTS: a row survived 20_cleanup. Same stop-and-look event the original would
-- have hit as ERROR 1452 inside section 8, but nothing has been created yet.
-- ---------------------------------------------------------------------

SET @step = 'documentuploadinternal/30_assert';
SET @t0 = NOW(3);
SET @orphans = 0;
SELECT COUNT(*) INTO @n FROM `documentuploadinternal` c
  LEFT JOIN `documentcategory` p0 ON c.`DocumentCategoryID` = p0.`ID`
 WHERE  (c.`DocumentCategoryID` IS NOT NULL AND p0.`ID` IS NULL);
SET @orphans = @orphans + @n;

-- Two-row subquery on the false branch: ERROR 1242, an abort, before 40_fk runs.
SELECT IF(@orphans = 0,
          'documentuploadinternal: orphan check OK - 0 rows across 1 relationships',
          (SELECT CONCAT('ABORT: ', @orphans, ' rows in `documentuploadinternal` still reference a parent that does not exist')
           UNION ALL
           SELECT 'Run 20_cleanup for this table first. Do NOT skip this check.')
       ) AS preflight_orphans;

INSERT INTO `_migration_ledger` (`step`, `applied_at`, `checksum`, `duration_ms`)
     VALUES (@step, NOW(), '9f17bcabff1e3dc58684bea966648b0b8ce270bbbbc9b49c16103654448a49b2', TIMESTAMPDIFF(MICROSECOND, @t0, NOW(3)) DIV 1000)
ON DUPLICATE KEY UPDATE `step` = `step`;
-- ---------------------------------------------------------------------
-- documentuploadinternal/40_fk  --  source section 8
-- The constraints, one ALTER for the whole table.
--
-- FOREIGN_KEY_CHECKS is turned OFF for this statement and restored afterwards. With
-- checks on InnoDB cannot add a foreign key in place -- it copies the whole table and
-- re-validates every row, which is where the original migration's 154 table copies
-- came from. The validation is not skipped, it MOVED: 30_assert proves zero orphans
-- and refuses to let this run otherwise.
-- ---------------------------------------------------------------------

SET @fk_prev = @@FOREIGN_KEY_CHECKS;

SET @step = 'documentuploadinternal/40_fk';
SET @todo = (SELECT COUNT(*) = 0 FROM `_migration_ledger` WHERE `step` = @step);
SET @t0 = NOW(3);
SET @sql = IF(@todo, 'ALTER TABLE `documentuploadinternal` ADD CONSTRAINT `documentuploadinternal_DocumentCategoryID` FOREIGN KEY (`DocumentCategoryID`) REFERENCES `documentcategory` (`ID`) ON DELETE RESTRICT ON UPDATE RESTRICT', 'DO 0');
PREPARE _step FROM @sql; EXECUTE _step; DEALLOCATE PREPARE _step;
INSERT INTO `_migration_ledger` (`step`, `applied_at`, `checksum`, `duration_ms`)
     VALUES (@step, NOW(), 'b4432cd0b68a26bf225dc8572b26ed15501066a485c7f850695093bcd5c0671a', TIMESTAMPDIFF(MICROSECOND, @t0, NOW(3)) DIV 1000)
ON DUPLICATE KEY UPDATE `step` = `step`;


-- --------------------------------------------------------------- postflight
-- DID THE WORK ACTUALLY LAND?
--
-- Every step records itself in `_migration_ledger` immediately after its statement runs,
-- WITHOUT checking that the statement succeeded. That is inherited from step/ unchanged,
-- and there it is safe because run.sh runs mysql without --force, so the first error stops
-- everything. Imported by hand, the client decides -- and "continue on error" would leave
-- failed steps marked applied.
--
-- So this file checks its own work against information_schema before it finishes. It is
-- the only thing here that is NOT copied from step/. It reads; it changes nothing.

-- postflight-set: fk
SET @want_fk = 5;
SELECT COUNT(*), IFNULL(SUBSTRING(GROUP_CONCAT(n ORDER BY n SEPARATOR ', '), 1, 60), '')
  INTO @missn_fk, @miss_fk
  FROM (SELECT 'documentgroupdivision.documentgroupdivision_DocID' AS n UNION ALL SELECT 'documentgroupdivision.documentgroupdivision_GroupDivID' UNION ALL SELECT 'documentupload.documentupload_DocumentCategoryID' UNION ALL SELECT 'documentupload.documentupload_PrincipalID' UNION ALL SELECT 'documentuploadinternal.documentuploadinternal_DocumentCategoryID') _w
 WHERE n NOT IN (SELECT CONCAT(TABLE_NAME, '.', CONSTRAINT_NAME) FROM information_schema.TABLE_CONSTRAINTS WHERE CONSTRAINT_SCHEMA = DATABASE() AND CONSTRAINT_TYPE = 'FOREIGN KEY');
SET @have_fk = @want_fk - @missn_fk;
SET @pf_fk = IF(@missn_fk = 0,
    CONCAT('SELECT ''postflight foreign keys: ', @have_fk, '/', @want_fk, ' present'' AS postflight_fk'),
    CONCAT('SELECT `ABORT postflight: MISSING foreign keys: ', @miss_fk,
           ' -- ', @missn_fk, ' of ', @want_fk, ' absent. A step is recorded in',
           ' _migration_ledger but did not take effect.`'));
PREPARE _pf FROM @pf_fk; EXECUTE _pf; DEALLOCATE PREPARE _pf;

-- postflight-set: idx
SET @want_idx = 5;
SELECT COUNT(*), IFNULL(SUBSTRING(GROUP_CONCAT(n ORDER BY n SEPARATOR ', '), 1, 60), '')
  INTO @missn_idx, @miss_idx
  FROM (SELECT 'documentgroupdivision.documentgroupdivision_DocID' AS n UNION ALL SELECT 'documentgroupdivision.documentgroupdivision_GroupDivID' UNION ALL SELECT 'documentupload.PrincipalID' UNION ALL SELECT 'documentupload.documentupload_DocumentCategoryID' UNION ALL SELECT 'documentuploadinternal.DocumentCategoryID') _w
 WHERE n NOT IN (SELECT CONCAT(TABLE_NAME, '.', INDEX_NAME) FROM information_schema.STATISTICS WHERE TABLE_SCHEMA = DATABASE());
SET @have_idx = @want_idx - @missn_idx;
SET @pf_idx = IF(@missn_idx = 0,
    CONCAT('SELECT ''postflight indexes: ', @have_idx, '/', @want_idx, ' present'' AS postflight_idx'),
    CONCAT('SELECT `ABORT postflight: MISSING indexes: ', @miss_idx,
           ' -- ', @missn_idx, ' of ', @want_idx, ' absent. A step is recorded in',
           ' _migration_ledger but did not take effect.`'));
PREPARE _pf FROM @pf_idx; EXECUTE _pf; DEALLOCATE PREPARE _pf;

-- postflight-set: typ
SET @want_typ = 5;
SELECT COUNT(*), IFNULL(SUBSTRING(GROUP_CONCAT(n ORDER BY n SEPARATOR ', '), 1, 60), '')
  INTO @missn_typ, @miss_typ
  FROM (SELECT 'documentgroupdivision.DocID.int' AS n UNION ALL SELECT 'documentgroupdivision.GroupDivID.int' UNION ALL SELECT 'documentupload.DocumentCategoryID.int' UNION ALL SELECT 'documentupload.PrincipalID.int' UNION ALL SELECT 'documentuploadinternal.DocumentCategoryID.int') _w
 WHERE n NOT IN (SELECT CONCAT(TABLE_NAME, '.', COLUMN_NAME, '.', DATA_TYPE) FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE());
SET @have_typ = @want_typ - @missn_typ;
SET @pf_typ = IF(@missn_typ = 0,
    CONCAT('SELECT ''postflight retyped columns: ', @have_typ, '/', @want_typ, ' present'' AS postflight_typ'),
    CONCAT('SELECT `ABORT postflight: MISSING retyped columns: ', @miss_typ,
           ' -- ', @missn_typ, ' of ', @want_typ, ' absent. A step is recorded in',
           ' _migration_ledger but did not take effect.`'));
PREPARE _pf FROM @pf_typ; EXECUTE _pf; DEALLOCATE PREPARE _pf;

-- --------------------------------------------------------------- restore
-- IFNULL on all four: if phpMyAdmin resumed this import on a fresh connection the
-- @OLD_ variables are gone, and a bare SET from NULL is ERROR 1231.
--
-- The CAST is on the two timeouts and NOWHERE ELSE, on purpose. An INTEGER system
-- variable rejects IFNULL()'s result type outright (ERROR 1232, every time, not only
-- when NULL). FOREIGN_KEY_CHECKS is a boolean and SQL_MODE is a set; both accept a
-- string result, so they need no CAST. Do not "fix" the asymmetry, and do not copy
-- line 3's shape onto a new integer variable.
SET SESSION lock_wait_timeout = CAST(IFNULL(@OLD_LOCK_WAIT, 86400) AS UNSIGNED);
SET SESSION innodb_lock_wait_timeout = CAST(IFNULL(@OLD_INNODB_LOCK_WAIT, 50) AS UNSIGNED);
