-- SyncLogArchive: permanent, append-only audit store for every Access change-log
-- row consumed by the incremental sync. This is the durable evidence layer that
-- SyncQueue is NOT: SyncQueue is a transient work queue (purged 24h after a row
-- is cleaned) and it only stores the *processed* OperateType, so a downgrade
-- (e.g. capture turning an Insert into a Delete when the row is momentarily
-- unreadable) erases the original intent. This table preserves both the ORIGINAL
-- operate type recorded by the Access data macro and the PROCESSED type actually
-- sent to SQL Server, plus the original Access log timestamp and the row payload.
--
-- With this in place, cases like the 14287 incident (a real Insert applied to SQL
-- as a Delete) stay fully reconstructible: OriginalOperateType != ProcessedOperateType
-- flags exactly where the pipeline diverged from the source.
--
-- Retention: PERMANENT. No purge job touches this table. SyncQueue keeps its
-- short-lived queue role; this table keeps history. Lives under the
-- ProductionDataBaseSync schema (run 00_schema.sql first).
-- Idempotent: safe to re-run.

IF OBJECT_ID('ProductionDataBaseSync.SyncLogArchive', 'U') IS NULL
BEGIN
    CREATE TABLE ProductionDataBaseSync.SyncLogArchive (
        ArchiveID            bigint IDENTITY(1,1) NOT NULL,
        SourceFile           nvarchar(255)        NOT NULL,
        SourceTable          nvarchar(255)        NOT NULL,
        SourceLogID          bigint               NOT NULL,
        RecordID             nvarchar(50)         NOT NULL,
        TargetSchema         nvarchar(128)        NOT NULL,
        TargetTable          nvarchar(255)        NOT NULL,
        OriginalOperateType  varchar(10)          NOT NULL,   -- as recorded by the Access data macro
        ProcessedOperateType varchar(10)          NOT NULL,   -- as actually sent to SyncQueue / SQL
        RowData              nvarchar(max)         NULL,       -- captured row payload (NULL for Delete)
        OriginalTime         datetime2             NULL,       -- Access TableChangeLog.Time (previously discarded)
        CapturedAt           datetime2             NOT NULL
                             CONSTRAINT DF_SyncLogArchive_Captured DEFAULT sysdatetime(),
        CONSTRAINT PK_SyncLogArchive PRIMARY KEY CLUSTERED (ArchiveID)
    );
END
GO

-- Dedup: one archive row per source log entry. Capture may re-run the same log
-- row if a prior cycle's apply failed (the Access log is only deleted after a
-- successful apply), so the write path uses IF NOT EXISTS on these keys.
IF NOT EXISTS (SELECT 1 FROM sys.indexes
               WHERE name = 'UX_SyncLogArchive_Dedup'
                 AND object_id = OBJECT_ID('ProductionDataBaseSync.SyncLogArchive'))
BEGIN
    CREATE UNIQUE INDEX UX_SyncLogArchive_Dedup
        ON ProductionDataBaseSync.SyncLogArchive(SourceFile, SourceTable, SourceLogID);
END
GO

-- Evidence lookup by table + record (e.g. "show every log ever seen for ID 14287").
IF NOT EXISTS (SELECT 1 FROM sys.indexes
               WHERE name = 'IX_SyncLogArchive_Record'
                 AND object_id = OBJECT_ID('ProductionDataBaseSync.SyncLogArchive'))
BEGIN
    CREATE INDEX IX_SyncLogArchive_Record
        ON ProductionDataBaseSync.SyncLogArchive(SourceTable, RecordID);
END
GO

-- Fast filter for the anomaly the archive exists to catch: original != processed.
IF NOT EXISTS (SELECT 1 FROM sys.indexes
               WHERE name = 'IX_SyncLogArchive_Divergence'
                 AND object_id = OBJECT_ID('ProductionDataBaseSync.SyncLogArchive'))
BEGIN
    CREATE INDEX IX_SyncLogArchive_Divergence
        ON ProductionDataBaseSync.SyncLogArchive(OriginalOperateType, ProcessedOperateType)
        INCLUDE (SourceFile, SourceTable, RecordID, CapturedAt);
END
GO