#!/usr/bin/env python3
"""Regenerate the committed seed corpora for alkstore's fuzz targets.

Writes into fuzz/corpus/<target>/. Deterministic: fixed inputs only, no
randomness. Run from the repo root:

    python3 fuzz/gen_fuzz_seeds.py

Target seed functions and the main() registry land here with the
target tasks; the shared seed_name()/write_seed() plumbing is stable.
"""

import os


def seed_name(target, i):
    return os.path.join("fuzz", "corpus", target, f"seed-{i:03d}")


def write_seed(target, i, data):
    path = seed_name(target, i)
    os.makedirs(os.path.dirname(path), exist_ok=True)
    with open(path, "wb") as f:
        f.write(data)


def payload_codec_seeds():
    i = 0

    # Valid JSON of every Value variant (numbers incl. bounds/floats,
    # strings incl. escapes/unicode, arrays, objects), plus whitespace
    # padding.
    valid_docs = [
        b"null",
        b"true",
        b"false",
        b"0",
        b"-1",
        b"-9223372036854775808",
        b"9223372036854775807",
        b"18446744073709551615",
        b"18446744073709551616",
        b"3.5",
        b"-2.25",
        b"1e10",
        b"1e309",
        b"-0",
        b'""',
        b'"hello world"',
        b'"unicode \\u00e9"',
        b'"emoji \\ud83d\\ude00"',
        b'"tab\\tnewline\\nquote\\"slash"',
        b'"null"',
        b"[]",
        b'[1, "two", null, true, {"three": 3}, []]',
        b"{}",
        b'{"a": 1}',
        b'{"a": 1, "nested": {"deep": [true, null, 3.5]}}',
        b'{"\\u00e9": "value"}',
        b'  \t\r\n{"spaced": true}\t\n  ',
    ]
    for doc in valid_docs:
        write_seed("payload_codec", i, doc)
        i += 1

    # Truncations at every prefix length of two representative docs.
    for doc in [b'{"a": 1, "b": [2, 3]}', b"[true, null, 1.5]"]:
        for n in range(1, len(doc)):
            write_seed("payload_codec", i, doc[:n])
            i += 1

    # Deep nesting: shallow, at/near serde_json's 128 recursion limit,
    # and well past it. Arrays and objects both.
    for depth in [8, 127, 128, 129, 256, 1024]:
        write_seed("payload_codec", i, ("[" * depth + "0" + "]" * depth).encode())
        i += 1
    for depth in [8, 200]:
        write_seed("payload_codec", i, ('{"a":' * depth + "1" + "}" * depth).encode())
        i += 1

    # Non-UTF-8 bytes inside and outside string positions.
    for raw in [b"\xff\xfe\xfd", b'{"a": "\xff"}', b"[1, 2\xff]"]:
        write_seed("payload_codec", i, raw)
        i += 1

    # Trailing garbage after a valid document.
    for raw in [
        b"{} trailing",
        b"[1]x",
        b"1 2",
        b"null null",
        b'"first""second"',
    ]:
        write_seed("payload_codec", i, raw)
        i += 1

    # Duplicate keys (canonicalization is serde_json's).
    for raw in [b'{"a": 1, "a": 2}', b'{"o": {"k": 1, "k": 2}, "o": 3}']:
        write_seed("payload_codec", i, raw)
        i += 1

    # The Null-decode shape: an empty byte store must never decode to
    # a silent Null (ADR-023 §1).
    for raw in [b"", b" ", b"null", b"nullx"]:
        write_seed("payload_codec", i, raw)
        i += 1

    # Other loud-fail shapes (typed `Codec` partition coverage).
    for raw in [
        b"NaN",
        b"Infinity",
        b"+1",
        b"01",
        b".5",
        b"1.",
        b"--1",
        b"{,}",
        b"[1,]",
        b'{"a"}',
        b'{"missing": }',
        b"\x80\x81\x82",
    ]:
        write_seed("payload_codec", i, raw)
        i += 1


def main():
    payload_codec_seeds()


if __name__ == "__main__":
    main()