;WITH MonthNames AS
(
    SELECT MonthNumber = 1, MonthName = N'January' UNION ALL
    SELECT 2, N'February' UNION ALL
    SELECT 3, N'March' UNION ALL
    SELECT 4, N'April' UNION ALL
    SELECT 5, N'May' UNION ALL
    SELECT 6, N'June' UNION ALL
    SELECT 7, N'July' UNION ALL
    SELECT 8, N'August' UNION ALL
    SELECT 9, N'September' UNION ALL
    SELECT 10, N'October' UNION ALL
    SELECT 11, N'November' UNION ALL
    SELECT 12, N'December'
),
LatestAgeEvidence AS
(
    SELECT
        evidence.CharacterID,
        runRows.ProjectID,
        EvidenceText = CONCAT(evidence.Value, N' ', evidence.Evidence),
        AgeValue = TRY_CONVERT(int, CASE
            WHEN evidence.Value IS NULL THEN NULL
            WHEN PATINDEX(N'%[^0-9]%', evidence.Value + N'x') = 1 THEN NULL
            ELSE LEFT(evidence.Value, PATINDEX(N'%[^0-9]%', evidence.Value + N'x') - 1)
        END),
        rn = ROW_NUMBER() OVER
        (
            PARTITION BY evidence.CharacterID
            ORDER BY runRows.CompletedUtc DESC, evidence.CharacterEnrichmentEvidenceID DESC
        )
    FROM dbo.CharacterEnrichmentEvidence evidence
    INNER JOIN dbo.CharacterEnrichmentRuns runRows ON runRows.CharacterEnrichmentRunID = evidence.CharacterEnrichmentRunID
    WHERE runRows.Status = N'Completed'
        AND evidence.FieldName = N'AgeAtStartOfSeries'
),
MatchedMonth AS
(
    SELECT
        ageEvidence.CharacterID,
        ageEvidence.ProjectID,
        ageEvidence.AgeValue,
        monthNames.MonthNumber,
        MonthPosition = CHARINDEX(monthNames.MonthName, ageEvidence.EvidenceText),
        ageEvidence.EvidenceText
    FROM LatestAgeEvidence ageEvidence
    INNER JOIN MonthNames monthNames ON CHARINDEX(monthNames.MonthName, ageEvidence.EvidenceText) > 0
    WHERE ageEvidence.rn = 1
        AND ageEvidence.AgeValue BETWEEN 1 AND 120
),
Parts AS
(
    SELECT
        matched.CharacterID,
        matched.ProjectID,
        matched.AgeValue,
        matched.MonthNumber,
        DayValue = TRY_CONVERT(int, REPLACE(REPLACE(REPLACE(REPLACE(dayParts.DayToken, N'st', N''), N'nd', N''), N'rd', N''), N'th', N'')),
        YearValue = TRY_CONVERT(int, LEFT(LTRIM(SUBSTRING(matched.EvidenceText, matched.MonthPosition + LEN(monthNames.MonthName), 20)), 4))
    FROM MatchedMonth matched
    INNER JOIN MonthNames monthNames ON monthNames.MonthNumber = matched.MonthNumber
    CROSS APPLY
    (
        SELECT Prefix = RTRIM(CASE WHEN matched.MonthPosition > 1 THEN LEFT(matched.EvidenceText, matched.MonthPosition - 1) ELSE N'' END)
    ) prefixParts
    CROSS APPLY
    (
        SELECT LastSpaceFromEnd = CHARINDEX(N' ', REVERSE(prefixParts.Prefix))
    ) spaceParts
    CROSS APPLY
    (
        SELECT DayToken = CASE
            WHEN LEN(prefixParts.Prefix) = 0 THEN N''
            WHEN spaceParts.LastSpaceFromEnd = 0 THEN prefixParts.Prefix
            ELSE RIGHT(prefixParts.Prefix, spaceParts.LastSpaceFromEnd - 1)
        END
    ) dayParts
),
Derived AS
(
    SELECT
        CharacterID,
        ProjectID,
        DateOfBirth = DATEADD(year, -AgeValue, DATEFROMPARTS(YearValue, MonthNumber, DayValue))
    FROM Parts
    WHERE DayValue BETWEEN 1 AND 31
        AND YearValue BETWEEN 1000 AND 9999
)
UPDATE c
SET BirthDate = derived.DateOfBirth,
    UpdatedDate = SYSUTCDATETIME()
FROM dbo.Characters c
INNER JOIN Derived derived ON derived.CharacterID = c.CharacterID AND derived.ProjectID = c.ProjectID
WHERE c.BirthDate IS NULL;
GO