1 files changed, 96 insertions, 0 deletions
diff --git a/lib/prefetch.ml b/lib/prefetch.ml
new file mode 100644
index 0000000..d5351e9
--- /dev/null
+++ b/lib/prefetch.ml
@@ -0,0 +1,96 @@
+(*─────────────────────────────────────────────────────────────────────────────┐
+│ SPDX-FileCopyrightText: 2025 toastal <https://toast.al/contact/>             │
+│ SPDX-License-Identifier: LGPL-2.1-or-later WITH OCaml-LGPL-linking-exception │
+└─────────────────────────────────────────────────────────────────────────────*)
+module Hash = struct
+	type t = {
+		algorithm: Input.Hash.algorithm;
+		value: string;
+	}
+	[@@deriving show]
+
+	let make_from_opts blake3 sha256 sha512 =
+		match blake3, sha256, sha512 with
+		| Some value, None, None -> {algorithm = Input.Hash.BLAKE3; value}
+		| None, Some value, None -> {algorithm = Input.Hash.SHA256; value}
+		| None, None, Some value -> {algorithm = Input.Hash.SHA512; value}
+		| None, None, None ->
+			Jsont.Error.msgf Jsont.Meta.none "Missing supported hash type"
+		| _, _, _ ->
+			Jsont.Error.msgf Jsont.Meta.none "Multiple supported hash types; expecting just 1"
+
+	let add_jsont_case obj =
+		let open Jsont in
+		obj
+		|> Object.opt_mem "blake3" string
+		|> Object.opt_mem "sha256" string
+		|> Object.opt_mem "sha512" string
+end
+
+module Git = struct
+	type t = {
+		datetime: string option;
+		rev: string;
+		hash: Hash.t;
+	}
+	[@@deriving make, show]
+
+	let jsont : t Jsont.t =
+		let open Jsont in
+		Object.map
+			~kind: "Prefetch_Git"
+			(fun datetime rev blake3 sha256 sha512 ->
+				let hash = Hash.make_from_opts blake3 sha256 sha512 in
+				make ?datetime ~rev ~hash ()
+			)
+		|> Object.opt_mem "date" string ~enc: (fun i -> i.datetime)
+		|> Object.mem "rev" string ~enc: (fun i -> i.rev)
+		|> Hash.add_jsont_case
+		|> Object.finish
+end
+
+module Darcs = struct
+	type t = {
+		datetime: string option;
+		context: string;
+		weak_hash: string;
+		hash: Hash.t;
+	}
+	[@@deriving make, show]
+
+	let jsont : t Jsont.t =
+		let open Jsont in
+		Object.map
+			~kind: "Prefetch_Darcs"
+			(fun datetime context weak_hash blake3 sha256 sha512 ->
+				let hash = Hash.make_from_opts blake3 sha256 sha512 in
+				make ?datetime ~context ~weak_hash ~hash ()
+			)
+		|> Object.opt_mem "date" string ~enc: (fun i -> i.datetime)
+		|> Object.mem "context" string ~enc: (fun i -> i.context)
+		|> Object.mem "weak-hash" string ~enc: (fun i -> i.weak_hash)
+		|> Hash.add_jsont_case
+		|> Object.finish
+end
+
+module Pijul = struct
+	type t = {
+		datetime: string option;
+		state: string;
+		hash: Hash.t
+	}
+	[@@deriving make, show]
+
+	let jsont : t Jsont.t =
+		let open Jsont in
+		Object.map
+			~kind: "Prefetch_Pijul"
+			(fun datetime state blake3 sha256 sha512 ->
+				let hash = Hash.make_from_opts blake3 sha256 sha512 in
+				make ?datetime ~state ~hash ()
+			)
+		|> Object.opt_mem "date" string ~enc: (fun i -> i.datetime)
+		|> Object.mem "state" string ~enc: (fun i -> i.state)
+		|> Hash.add_jsont_case
+		|> Object.finish
+end