import os, json, requests
from getpass import getpass

def valid_elabfiles(path):
    '''Lookup directory "path" and
       returns list of valid eLabFTW
       Experiment JSON files.'''
    elabfiles = []
    for filename in os.listdir(path):
        if filename.endswith(".json"):
            try:
                with open(os.path.join(path, filename), "r") as f:
                    data = json.load(f)
                    if data.get("elabid"): # insert specific NeXus requirements here later
                        
                        elabfiles.append(filename)
                f.close()
            except json.decoder.JSONDecodeError as e: # invalid files "masked" as JSON
                #print(f"wait a moment: {e}") # just for debug
                pass
    return elabfiles

def call_sample(apikey, elabid, SERVER_URL="https://elabftw.fisica.unina.it/"): # TO-DO: rm default server
    '''Queries the Resources (/items) API endpoint
       of eLabFTW instance to request data (JSON)
       on a certain sample given its eLab-ID.
       
       Requires an active (RO/RW) API key.
       Defaults to elabftw.fisica.unina.it.'''
    full_elab_url = f"{SERVER_URL}api/v2" # API endpoint root for eLabFTW
    items_url = f"{full_elab_url}/items" # API endpoint /items
    header = {
        "Authorization": apikey,
        "Content-Type": "application/json"
    }
    sample = requests.get(
        headers=header,
        url=f"{items_url}/{elabid}",
        verify=True
    )
    return sample.json()

def id2sample(apikey, elabid):
    '''Fetches sample data (JSON) from eLabFTW
       instance (using function "call_sample()")
       and extracts significant information.
       
       Currently, it only returns the sample's title.'''
    #apikey = getpass("Paste API key here: ") # move outside loops
    sample_data = call_sample(apikey, elabid)
    sample_title = sample_data["title"]
    return sample_title

def fetch_and_group(path):
    '''Fetches experiment data from eLabFTW JSON
       files in a given folder, then 
    '''
    sample_dict = {}
    apikey = getpass("Paste API key here: ")
    for filename in valid_elabfiles(path):
        with open(os.path.join(path, filename), "r") as f:
            layer = json.load(f)
            extra = layer["metadata_decoded"]["extra_fields"]
            sample_id = extra["Sample"]["value"]
            sample_title = id2sample(apikey, sample_id)
            lpn = int(extra["Layer Progressive Number"]["value"]) # Layer Progressive Number
            if not sample_dict.get(sample_title): # if not existent yet, initialize
                sample_dict[sample_title] = {
                    "instrument": {
                        "deposition_chamber": extra["Chamber"]["value"], # ID of associated resource (PLD chamber) - useless as is!
                        "laser_system": extra["Laser System"]["value"],
                        "rheed_system": extra["RHEED System"]["value"]
                    },
                    "multilayer": {}
                    }
            sample_dict[sample_title]["multilayer"][f"layer_{lpn}"] = {
                "operator": layer["fullname"],
                "created_at": layer["created_at"],
                "sample": extra["Sample"], # ID of associated sample - useless as is!
                "temperature": extra["Heater temperature "], # space at the end is a config error in eLab!
                "target": extra["Target"]
            }
    return sample_dict

sample_dict = fetch_and_group("./tests/objects")
print(json.dumps(sample_dict, indent=3))