From e3ccc9d82b20a4efeef7734d98c610ece3e0f9f3 Mon Sep 17 00:00:00 2001
From: Fabian Gans <fabiangans@gmx.de>
Date: Wed, 21 Aug 2024 17:17:30 +0200
Subject: [PATCH] Factor out DateTime64 type (#145)

* Factor out DateTime64 into dep

* fix typestr parsing
---
 Project.toml    |  2 ++
 src/ZArray.jl   |  6 ++++--
 src/metadata.jl | 35 +++--------------------------------
 3 files changed, 9 insertions(+), 34 deletions(-)

diff --git a/Project.toml b/Project.toml
index 27c0cd9..77b6e11 100644
--- a/Project.toml
+++ b/Project.toml
@@ -9,6 +9,7 @@ Blosc = "a74b3585-a348-5f62-a45c-50e91977d574"
 CodecZlib = "944b1d66-785c-5afd-91f1-9de20f533193"
 DataStructures = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
+DateTimes64 = "b342263e-b350-472a-b1a9-8dfd21b51589"
 DiskArrays = "3c3547ce-8d99-4f5e-a174-61eb10b00ae3"
 HTTP = "cd3eb016-35fb-5094-929b-558a96fad6f3"
 JSON = "682c06a0-de6a-54ab-a142-c8b1cf79cde6"
@@ -24,6 +25,7 @@ AWSS3 = "0.10"
 Blosc = "0.5, 0.6, 0.7"
 CodecZlib = "0.6, 0.7"
 DataStructures = "0.17, 0.18"
+DateTimes64 = "1"
 DiskArrays = "0.4.2"
 HTTP = "^1.3"
 JSON = "0.21"
diff --git a/src/ZArray.jl b/src/ZArray.jl
index 1cd7255..acbf23e 100644
--- a/src/ZArray.jl
+++ b/src/ZArray.jl
@@ -2,6 +2,8 @@ import JSON
 import OffsetArrays: OffsetArray
 import DiskArrays: AbstractDiskArray
 import DiskArrays
+using DateTimes64: DateTime64
+using Dates: Day, Millisecond
 
 """
 Number of tasks to use for async reading of chunks. Warning: setting this to very high values can lead to a large memory footprint. 
@@ -372,8 +374,8 @@ filterfromtype(::Type{<:Union{MaxLengthString, Union{MaxLengthString, Missing}}}
 #Not all Array types can be mapped directly to a valid ZArray encoding.
 #Here we try to determine the correct element type
 to_zarrtype(::AbstractArray{T}) where T = T
-to_zarrtype(a::AbstractArray{<:Date}) = DateTime64{Dates.Day}
-to_zarrtype(a::AbstractArray{<:DateTime}) = DateTime64{Dates.Millisecond}
+to_zarrtype(a::AbstractArray{<:Date}) = DateTime64{Day}
+to_zarrtype(a::AbstractArray{<:DateTime}) = DateTime64{Millisecond}
 
 function ZArray(a::AbstractArray, args...; kwargs...)
   z = zcreate(to_zarrtype(a), args..., size(a)...; kwargs...)
diff --git a/src/metadata.jl b/src/metadata.jl
index c7660e7..f3dc5df 100644
--- a/src/metadata.jl
+++ b/src/metadata.jl
@@ -1,4 +1,5 @@
 import Dates: Date, DateTime
+using DateTimes64: DateTime64, pydatetime_string, datetime_from_pystring 
 
 """NumPy array protocol type string (typestr) format
 
@@ -21,37 +22,7 @@ Base.codepoint(x::ASCIIChar) = UInt8(x)
 Base.show(io::IO, x::ASCIIChar) = print(io, Char(x))
 Base.zero(::Union{ASCIIChar,Type{ASCIIChar}}) = ASCIIChar(Base.zero(UInt8))
 
-
-using Dates: Period, TimeType, Date, DateTime, Dates
-import Base.==
-struct DateTime64{P} <: TimeType
-    i::Int64
-end
-Base.convert(::Type{Date},t::DateTime64{P}) where P = Date(1970)+P(t.i)
-Base.convert(::Type{DateTime},t::DateTime64{P}) where P = DateTime(1970)+P(t.i)
-Base.show(io::IO,t::DateTime64{P}) where P = print(io,"DateTime64[",P,"]: ",string(DateTime(t)))
-Base.isless(x::DateTime64{P}, y::DateTime64{P}) where P = isless(x.i, y.i)
-==(x::DateTime64{P}, y::DateTime64{P}) where P = x.i == y.i
-strpairs = [Dates.Year => "Y", Dates.Month => "M", Dates.Week => "W", Dates.Day=>"D", 
-    Dates.Hour => "h", Dates.Minute => "m", Dates.Second=>"s", Dates.Millisecond =>"ms",
-    Dates.Microsecond => "us", Dates.Nanosecond => "ns"]
-const jlperiod = Dict{String,Any}()
-const pdt64string = Dict{Any, String}()
-for p in strpairs
-    jlperiod[p[2]] = p[1]
-    pdt64string[p[1]] = p[2]
-end
-Base.convert(::Type{DateTime64{P}}, t::Date) where P = DateTime64{P}(Dates.value(P(t-Date(1970))))
-Base.convert(::Type{DateTime64{P}}, t::DateTime) where P = DateTime64{P}(Dates.value(P(t-DateTime(1970))))
-Base.convert(::Type{DateTime64{P}}, t::DateTime64{Q}) where {P,Q} = DateTime64{P}(Dates.value(P(Q(t.i))))
-Base.zero(t::Union{DateTime64, Type{<:DateTime64}}) = t(0)
 Base.zero(t::Union{String, Type{String}}) = ""
-# Base.promote_rule(::Type{<:DateTime64{<:Dates.DatePeriod}}, ::Type{Date}) = Date 
-# Base.promote_rule(::Type{<:DateTime64{<:Dates.DatePeriod}}, ::Type{DateTime}) = DateTime
-# Base.promote_rule(::Type{<:DateTime64{<:Dates.TimePeriod}}, ::Type{Date}) = DateTime 
-# Base.promote_rule(::Type{<:DateTime64{<:Dates.TimePeriod}}, ::Type{DateTime}) = DateTime
-
-
 
 typestr(t::Type) = string('<', 'V', sizeof(t))
 typestr(t::Type{>:Missing}) = typestr(Base.nonmissingtype(t))
@@ -63,7 +34,7 @@ typestr(t::Type{<:AbstractFloat}) = string('<', 'f', sizeof(t))
 typestr(::Type{MaxLengthString{N,UInt32}}) where N = string('<', 'U', N)
 typestr(::Type{MaxLengthString{N,UInt8}}) where N = string('<', 'S', N)
 typestr(::Type{<:Array}) = "|O"
-typestr(::Type{<:DateTime64{P}}) where P = "<M8[$(pdt64string[P])]"
+typestr(t::Type{<:DateTime64}) = pydatetime_string(t)
 typestr(::Type{<:AbstractString}) = "|O"
 
 const typestr_regex = r"^([<|>])([tbiufcmMOSUV])(\d*)(\[\w+\])?$"
@@ -107,7 +78,7 @@ function typestr(s::AbstractString, filterlist=nothing)
         end
         if tc == 'M' && ts == 8
             #We have a datetime64 value
-            return DateTime64{jlperiod[String(typespec)[2:end-1]]}
+            return datetime_from_pystring(s)
         end
         # convert typecode to Char and typesize to Int
         typemap[(tc,ts)]