(ns DateTime
  "Elixir DateTime module — date and time with timezone.

   In CljElixir: (DateTime/utc-now), (DateTime/to-iso8601 dt), etc.")

(defn utc-now
  "Returns the current UTC datetime.
   (DateTime/utc-now) ;=> ~U[2024-03-09 12:00:00Z]
   (DateTime/utc-now Calendar.ISO)"
  ([])
  ([calendar]))

(defn now
  "Returns the current datetime for a timezone.
   (DateTime/now \"Etc/UTC\") ;=> {:ok datetime}"
  ([timezone])
  ([timezone calendar]))

(defn now!
  "Returns the current datetime. Raises on error.
   (DateTime/now! \"Etc/UTC\")"
  ([timezone])
  ([timezone calendar]))

(defn new
  "Creates a new DateTime.
   (DateTime/new 2024 3 9 12 0 0)"
  ([date time])
  ([date time timezone])
  ([date time timezone database]))

(defn new!
  "Creates a new DateTime. Raises on error."
  ([date time])
  ([date time timezone])
  ([date time timezone database]))

(defn from-unix
  "Converts Unix timestamp to DateTime.
   (DateTime/from-unix 1709985600) ;=> {:ok datetime}
   (DateTime/from-unix 1709985600000 :millisecond)"
  ([integer])
  ([integer unit])
  ([integer unit calendar]))

(defn from-unix!
  "Converts Unix timestamp. Raises on error.
   (DateTime/from-unix! 1709985600)"
  ([integer])
  ([integer unit])
  ([integer unit calendar]))

(defn to-unix
  "Converts DateTime to Unix timestamp.
   (DateTime/to-unix datetime) ;=> 1709985600
   (DateTime/to-unix datetime :millisecond)"
  ([datetime])
  ([datetime unit]))

(defn from-iso8601
  "Parses ISO 8601 string. Returns {:ok datetime utc-offset}.
   (DateTime/from-iso8601 \"2024-03-09T12:00:00Z\") ;=> {:ok datetime 0}"
  ([string])
  ([string calendar-or-format]))

(defn from-iso8601!
  "Parses ISO 8601. Raises on error."
  ([string])
  ([string calendar-or-format]))

(defn to-iso8601
  "Converts to ISO 8601 string.
   (DateTime/to-iso8601 datetime) ;=> \"2024-03-09T12:00:00Z\""
  ([datetime])
  ([datetime format])
  ([datetime format offset]))

(defn to-string
  "Converts to human-readable string.
   (DateTime/to-string datetime) ;=> \"2024-03-09 12:00:00Z\""
  [datetime])

(defn to-date
  "Extracts the Date part.
   (DateTime/to-date datetime) ;=> ~D[2024-03-09]"
  [datetime])

(defn to-time
  "Extracts the Time part.
   (DateTime/to-time datetime) ;=> ~T[12:00:00]"
  [datetime])

(defn to-naive
  "Converts to NaiveDateTime (drops timezone info).
   (DateTime/to-naive datetime) ;=> ~N[2024-03-09 12:00:00]"
  [datetime])

(defn from-naive
  "Converts NaiveDateTime to DateTime with timezone.
   (DateTime/from-naive naive \"Etc/UTC\") ;=> {:ok datetime}"
  ([naive-datetime timezone])
  ([naive-datetime timezone database]))

(defn from-naive!
  "Converts NaiveDateTime. Raises on error."
  ([naive-datetime timezone])
  ([naive-datetime timezone database]))

(defn add
  "Adds `amount` of time to a datetime.
   (DateTime/add datetime 3600) ;=> +1 hour
   (DateTime/add datetime 1 :hour)"
  ([datetime amount])
  ([datetime amount unit]))

(defn diff
  "Returns the difference between two datetimes.
   (DateTime/diff dt1 dt2) ;=> seconds
   (DateTime/diff dt1 dt2 :hour) ;=> hours"
  ([datetime1 datetime2])
  ([datetime1 datetime2 unit]))

(defn shift-zone
  "Shifts datetime to a different timezone.
   (DateTime/shift-zone datetime \"America/New_York\")"
  ([datetime timezone])
  ([datetime timezone database]))

(defn shift-zone!
  "Shifts timezone. Raises on error."
  ([datetime timezone])
  ([datetime timezone database]))

(defn truncate
  "Truncates datetime to given precision.
   (DateTime/truncate datetime :second)"
  [datetime precision])

(defn compare
  "Compares two datetimes. Returns :lt, :eq, or :gt.
   (DateTime/compare dt1 dt2) ;=> :lt"
  [datetime1 datetime2])

(defn before?
  "Returns true if `datetime1` is before `datetime2`."
  [datetime1 datetime2])

(defn after?
  "Returns true if `datetime1` is after `datetime2`."
  [datetime1 datetime2])

(defn shift
  "Shifts datetime by a duration.
   (DateTime/shift datetime :hour 1 :minute 30)"
  [datetime duration])