import json
from pathlib import Path
import shutil
from typer.testing import CliRunner

from spriteforge.backend_registry import register_backend_contract
from spriteforge.backends.base import Backend,BackendContext,RawAsset
from spriteforge.backends.registry import register_backend
from spriteforge.cache import input_hash
from spriteforge.cli import app
from spriteforge.manifest import AssetEntry,AssetSpec

runner=CliRunner()

def manifest_file(tmp_path):
    path=tmp_path/"assets.yaml"
    path.write_text("""\
a_floor:
  backend: procedural
  generator: floor_tile
  params: {width: 24, height: 12, color: '#605040'}
b_decal:
  backend: procedural
  generator: decal
  params: {width: 20, height: 10, color: '#904030'}
""")
    return path

def build(path,output,cache,*extra):
    return runner.invoke(app,["build",str(path),"--output",str(output),"--cache-dir",str(cache),*extra])

def test_second_build_hits_artifact_cache(tmp_path):
    path=manifest_file(tmp_path);output=tmp_path/"out";cache=tmp_path/"cache"
    first=build(path,output,cache,"--jobs","2")
    assert first.exit_code==0 and "generated=2" in first.stdout
    second=build(path,output,cache,"--jobs","2")
    assert second.exit_code==0 and "artifact=2" in second.stdout and "generated=0" in second.stdout

def test_raw_cache_survives_artifact_eviction(tmp_path):
    path=manifest_file(tmp_path);output=tmp_path/"out";cache=tmp_path/"cache"
    assert build(path,output,cache).exit_code==0
    shutil.rmtree(cache/"artifacts")
    repeated=build(path,output,cache)
    assert repeated.exit_code==0 and "raw=2" in repeated.stdout and "artifact=0" in repeated.stdout

def test_metadata_tags_do_not_invalidate_render_or_artifact(tmp_path):
    path=manifest_file(tmp_path);output=tmp_path/"out";cache=tmp_path/"cache"
    assert build(path,output,cache).exit_code==0
    path.write_text(path.read_text().replace("a_floor:\n", "a_floor:\n  tags: [environment]\n"))
    repeated=build(path,output,cache)
    assert repeated.exit_code==0 and "generated=0" in repeated.stdout and "artifact=2" in repeated.stdout
    index=json.loads((output/"index.json").read_text())
    assert next(item for item in index["assets"] if item["id"]=="a_floor")["tags"]==["environment"]

def test_one_asset_change_preserves_other_and_palette(tmp_path):
    path=manifest_file(tmp_path);output=tmp_path/"out";cache=tmp_path/"cache"
    assert build(path,output,cache).exit_code==0
    old=json.loads((output/"index.json").read_text());old_items={x["id"]:x for x in old["assets"]};palette=old["palette"]["hash"]
    path.write_text(path.read_text().replace("#605040","#405870"))
    changed=build(path,output,cache,"--asset","a_floor")
    assert changed.exit_code==0 and "generated=1" in changed.stdout
    new=json.loads((output/"index.json").read_text());new_items={x["id"]:x for x in new["assets"]}
    assert new_items["b_decal"]==old_items["b_decal"]
    assert new_items["a_floor"]["hash"]!=old_items["a_floor"]["hash"]
    assert new["palette"]["hash"]==palette

class DependencyBackend(Backend):
    name="dependency_test";version="1"
    def dependencies(self,spec,context):return (Path(spec.params["path"]),)
    def generate(self,spec,context)->RawAsset:raise AssertionError("not used")

def test_dependency_bytes_invalidate_input_hash(tmp_path):
    register_backend_contract("dependency_test",lambda spec:None,replace=True)
    register_backend("dependency_test",DependencyBackend,replace=True)
    source=tmp_path/"source.bin";source.write_bytes(b"one")
    spec=AssetSpec(backend="dependency_test",params={"path":str(source)})
    entry=AssetEntry("thing",spec,tmp_path/"assets.yaml",1)
    before=input_hash(entry)[0];source.write_bytes(b"two");after=input_hash(entry)[0]
    assert before!=after

def test_filtered_palette_rebuild_is_rejected(tmp_path):
    path=manifest_file(tmp_path)
    result=build(path,tmp_path/"out",tmp_path/"cache","--asset","a_floor","--rebuild-palette")
    assert result.exit_code==2 and "unfiltered full build" in result.stderr