import json
import subprocess
from pathlib import Path


SYNC = Path(__file__).parents[1] / "frontend" / "unfiled-draft-sync.js"


def run_node(script: str):
    result = subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True)
    return json.loads(result.stdout)


def test_unfiled_draft_sync_moves_capture_between_devices_and_propagates_delete():
    script = f"""
const createSync=require({json.dumps(str(SYNC))});
let remote={{revision:0,drafts:[]}};
function api(url,init={{}}) {{
  if (!init.method) return Promise.resolve(JSON.parse(JSON.stringify(remote)));
  const body=JSON.parse(init.body);
  if (body.revision!==remote.revision) {{
    const error=new Error('conflict');error.status=409;error.payload={{detail:{{snapshot:remote}}}};return Promise.reject(error);
  }}
  remote={{revision:remote.revision+1,drafts:body.drafts}};
  return Promise.resolve(JSON.parse(JSON.stringify(remote)));
}}
function device(initial=[]) {{
  let drafts=initial.map(item=>({{...item}})); const values=new Map(); const states=[];
  const captures={{
    exportOwned:async()=>drafts.map(item=>({{...item}})),
    mergeRemote:async(items)=>{{let count=0;for(const item of items)if(!drafts.some(x=>x.id===item.id)){{drafts.push({{...item}});count++}}return count}},
    discard:async id=>{{drafts=drafts.filter(item=>item.id!==id);return true}},
  }};
  const storage={{getItem:key=>values.get(key)||null,setItem:(key,value)=>values.set(key,value)}};
  const sync=createSync({{captures,fetchJson:api,storage,onState:state=>states.push(state)}});
  return {{sync,states,drafts:()=>drafts}};
}}
(async()=>{{
  const phone=device([{{id:'field',title:'Field failure',body:'Steps',saved_at:42,evidence:[{{filename:'proof.png',content_type:'image/png',data:'cHJvb2Y='}}]}}]);
  await phone.sync.sync('timmy');
  const desktop=device();
  await desktop.sync.sync('timmy');
  await desktop.sync.remove('field','timmy');
  await phone.sync.sync('timmy');
  process.stdout.write(JSON.stringify({{
    remote,desktop:desktop.drafts(),phone:phone.drafts(),
    phoneStates:phone.states.map(x=>x.status),desktopStates:desktop.states.map(x=>x.status),
  }}));
}})().catch(error=>{{console.error(error);process.exit(1)}});
"""
    output = run_node(script)

    assert output["remote"]["revision"] == 2
    assert output["remote"]["drafts"] == []
    assert output["desktop"] == []
    assert output["phone"] == []
    assert output["phoneStates"][-1] == "ready"
    assert output["desktopStates"][-1] == "ready"


def test_unfiled_draft_sync_surfaces_revision_conflict_without_losing_local_draft():
    script = f"""
const createSync=require({json.dumps(str(SYNC))});
let calls=0;const states=[];let drafts=[{{id:'local',title:'Local',body:'',saved_at:1}}];
const conflict={{revision:2,drafts:[{{id:'remote',title:'Remote',body:'',saved_at:2}}]}};
const sync=createSync({{
  captures:{{exportOwned:async()=>drafts,mergeRemote:async()=>0,discard:async()=>true}},
  storage:{{getItem:()=>null,setItem:()=>{{}}}},
  fetchJson:async(_url,init)=>{{calls++;if(!init)return {{revision:1,drafts:[]}};const error=new Error('conflict');error.status=409;error.payload={{detail:{{snapshot:conflict}}}};throw error}},
  onState:state=>states.push(state),
}});
(async()=>{{let message='';try{{await sync.sync('timmy')}}catch(error){{message=error.message}}process.stdout.write(JSON.stringify({{calls,states,message,drafts}}))}})();
"""
    output = run_node(script)

    assert output["calls"] == 2
    assert output["states"][-1]["status"] == "conflict"
    assert output["states"][-1]["message"] == "Drafts changed on another device. Sync again to combine them."
    assert output["drafts"][0]["id"] == "local"


def test_unfiled_draft_sync_coalesces_overlapping_reconnects_without_self_conflict():
    script = f"""
const createSync=require({json.dumps(str(SYNC))});
let remote={{revision:0,drafts:[]}}, gets=0, puts=0, release;
const gate=new Promise(resolve=>release=resolve);
const api=async(_url,init)=>{{
  if(!init){{gets++;if(gets===1)await gate;return JSON.parse(JSON.stringify(remote))}}
  puts++;const body=JSON.parse(init.body);
  if(body.revision!==remote.revision){{const error=new Error('conflict');error.status=409;error.payload={{detail:{{snapshot:remote}}}};throw error}}
  remote={{revision:remote.revision+1,drafts:body.drafts}};return remote;
}};
const draft={{id:'local',title:'Local',body:'',saved_at:1}};
const sync=createSync({{
  captures:{{exportOwned:async()=>[draft],mergeRemote:async()=>0,discard:async()=>true}},
  storage:{{getItem:()=>null,setItem:()=>{{}}}},fetchJson:api,
}});
(async()=>{{const first=sync.sync('timmy'),second=sync.sync('timmy');release();const results=await Promise.all([first,second]);process.stdout.write(JSON.stringify({{gets,puts,results,remote}}))}})();
"""
    output = run_node(script)

    assert output["puts"] == 1
    assert output["remote"]["drafts"][0]["id"] == "local"
    assert output["results"] == [True, True]