pig

-module(pig@workspace@kv).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/pig/workspace/kv.gleam").
-export([remember/3, recall/2, list_keys/2]).
-export_type([error/0]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

?MODULEDOC(" Key-value store operations for pig workspace.\n").

-type error() :: {sql_error, sqlight:error()} | {not_found, binary()}.

-file("src/pig/workspace/kv.gleam", 24).
?DOC(
    " Store a key-value pair, updating the value if the key already exists.\n"
    "\n"
    " Uses an upsert operation (INSERT ... ON CONFLICT DO UPDATE) to handle\n"
    " both new keys and updates to existing keys atomically.\n"
    "\n"
    " # Example\n"
    " ```gleam\n"
    " let assert Ok(Nil) = kv.remember(conn, \"user:1\", \"Alice\")\n"
    " let assert Ok(Nil) = kv.remember(conn, \"user:1\", \"Alice Smith\")  // Updates\n"
    " ```\n"
).
-spec remember(sqlight:connection(), binary(), binary()) -> {ok, nil} |
    {error, error()}.
remember(Conn, Key, Value) ->
    Sql = <<"
INSERT INTO kv_store (key, value, updated_at)
VALUES (?, ?, unixepoch())
ON CONFLICT(key) DO UPDATE SET
  value = excluded.value,
  updated_at = unixepoch()
RETURNING key
"/utf8>>,
    _pipe = sqlight:'query'(
        Sql,
        Conn,
        [sqlight:text(Key), sqlight:text(Value)],
        gleam@dynamic@decode:at(
            [0],
            {decoder, fun gleam@dynamic@decode:decode_string/1}
        )
    ),
    _pipe@1 = gleam@result:map_error(
        _pipe,
        fun(Field@0) -> {sql_error, Field@0} end
    ),
    gleam@result:map(_pipe@1, fun(_) -> nil end).

-file("src/pig/workspace/kv.gleam", 61).
?DOC(
    " Retrieve a value by key.\n"
    "\n"
    " Returns an error if the key doesn't exist.\n"
    "\n"
    " # Example\n"
    " ```gleam\n"
    " case kv.recall(conn, \"user:1\") {\n"
    "   Ok(name) -> io.println(\"Found: \" <> name)\n"
    "   Error(kv.NotFound(key)) -> io.println(\"Key not found: \" <> key)\n"
    "   Error(_) -> io.println(\"Database error\")\n"
    " }\n"
    " ```\n"
).
-spec recall(sqlight:connection(), binary()) -> {ok, binary()} |
    {error, error()}.
recall(Conn, Key) ->
    Sql = <<"SELECT value FROM kv_store WHERE key = ?"/utf8>>,
    _pipe = sqlight:'query'(
        Sql,
        Conn,
        [sqlight:text(Key)],
        gleam@dynamic@decode:at(
            [0],
            {decoder, fun gleam@dynamic@decode:decode_string/1}
        )
    ),
    _pipe@1 = gleam@result:map_error(
        _pipe,
        fun(Field@0) -> {sql_error, Field@0} end
    ),
    gleam@result:'try'(_pipe@1, fun(Rows) -> case Rows of
                [Value] ->
                    {ok, Value};

                _ ->
                    {error, {not_found, Key}}
            end end).

-file("src/pig/workspace/kv.gleam", 100).
?DOC(" Escape SQL LIKE wildcard characters (%, _, \\) so they match literally.\n").
-spec escape_like(binary()) -> binary().
escape_like(S) ->
    _pipe = S,
    _pipe@1 = gleam@string:replace(_pipe, <<"\\"/utf8>>, <<"\\\\"/utf8>>),
    _pipe@2 = gleam@string:replace(_pipe@1, <<"%"/utf8>>, <<"\\%"/utf8>>),
    gleam@string:replace(_pipe@2, <<"_"/utf8>>, <<"\\_"/utf8>>).

-file("src/pig/workspace/kv.gleam", 82).
?DOC(
    " List all keys that start with the given prefix, sorted alphabetically.\n"
    "\n"
    " Escapes SQL LIKE wildcards in the prefix so they match literally.\n"
).
-spec list_keys(sqlight:connection(), binary()) -> {ok, list(binary())} |
    {error, error()}.
list_keys(Conn, Prefix) ->
    Escaped = escape_like(Prefix),
    Sql = <<"SELECT key FROM kv_store WHERE key LIKE ? || '%' ESCAPE '\\' ORDER BY key ASC"/utf8>>,
    _pipe = sqlight:'query'(
        Sql,
        Conn,
        [sqlight:text(Escaped)],
        gleam@dynamic@decode:at(
            [0],
            {decoder, fun gleam@dynamic@decode:decode_string/1}
        )
    ),
    gleam@result:map_error(_pipe, fun(Field@0) -> {sql_error, Field@0} end).