"""
run this before using this library:
ipython -i keithley_interactive.py
"""

import numpy as np
import matplotlib.pyplot as plt
import pandas as pd

from datetime import datetime as dtime
from sys import exit
from time import sleep
from os import path, makedirs
import pickle as pkl
import json

if __name__ == "__main__":
    if __package__ is None:
        # make relative imports work as described here: https://peps.python.org/pep-0366/#proposed-change
        __package__ = "k-teng"
        import sys
        from os import path
        filepath = path.realpath(path.abspath(__file__))
        sys.path.insert(0, path.dirname(path.dirname(filepath)))


from .keithley import keithley as _keithley
from .utility import data
from .utility import file_io
from .utility import testing

_runtime_vars = {
    "last-measurement": ""
}

settings = {
    "datadir":      path.expanduser("~/data"),
    "name":         "measurement",
    "interval":     0.01,
    "beep":         True,
}
config_path = path.expanduser("~/.config/k-teng.json")

test = False

# global variable for the instrument returned by pyvisa
k = None


def _measure(max_measurements=None, max_points_shown=None, monitor=False):
    """
    Monitor the voltage with matplotlib.

    @details:
        - Resets the buffers
        - Opens a matplotlib window and takes measurements depending on settings["interval"]
        - Waits for the user to press a key
    @param max_points_shown : how many points should be shown at once. None means infinite
    @param max_measurements : maximum number of measurements. None means infinite
    You can take the data from the buffer afterwards, using save_csv """
    global k, settings, test, _runtime_vars
    print(f"Starting measurement with:\n\tinterval = {settings['interval']}s\nUse <C-c> to stop. Save the data using 'save_csv()' afterwards.")
    _runtime_vars["last_measurement"] = dtime.now().isoformat()
    # jupyter:
    # clear_output(wait=True)
    # plt.plot(data)
    # plt.show()
    index = []
    data = []
    if monitor:
        plt.ion()
        fig = plt.figure()
        ax = fig.add_subplot(ylabel="Voltage [V]")
        line1,  = ax.plot(index, data)
    try:
        i = 0
        while max_measurements is None or i < max_measurements:
            index.append(i)
            if test:
                data.append(testing.testcurve(i))
                # data.append(tuple(float(v) for v in instr.query("print(smua.measure.v())").strip('\n').split('\t')))
            else:
                data.append(k.query("print(smua.measure.v())").strip('\n'))
                # data.append(np.random.rand())
            print(f"{i:5d} - {data[-1]:.5f} V", end='\r')
            if monitor:
                # update data
                line1.set_xdata(index)
                line1.set_ydata(data)
                # recalculate limits and set them for the view
                ax.relim()
                if max_points_shown and i > max_points_shown:
                    ax.set_xlim(i - max_points_shown, i)
                ax.autoscale_view()
                # update plot
                fig.canvas.draw()
                fig.canvas.flush_events()
            sleep(settings["interval"])
            i += 1
    except KeyboardInterrupt:
        if monitor:
            plt.close(fig)
        print("Measurement stopped" + " "*50)


def monitor(max_measurements=None, max_points_shown=None, ):
    """
    Monitor the voltage with matplotlib.

    @details:
        - Resets the buffers
        - Opens a matplotlib window and takes measurements depending on settings["interval"]
        - Waits for the user to press a key
    @param max_points_shown : how many points should be shown at once. None means infinite
    @param max_measurements : maximum number of measurements. None means infinite
    You can take the data from the buffer afterwards, using save_csv """
    _measure(max_measurements=max_measurements, max_points_shown=max_points_shown, monitor=True)


def measure(max_measurements=None):
    """
    Measure voltages

    @details:
        - Resets the buffers
        - Measure voltages
        - Waits for the user to press a key
    @param max_measurements : maximum number of measurements. None means infinite
    You can take the data from the buffer afterwards, using save_csv """
    _measure(max_measurements=max_measurements, monitor=False)


def get_dataframe():
    global k, settings, _runtime_vars
    if test:
        timestamps = np.arange(0, 50, 0.01)
        ydata = np.array([testing.testcurve(t) for t in timestamps])
        buffer = np.vstack((timestamps, ydata)).T
    else:
        buffer = _keithley.collect_buffer(k, 1)
    df = data.buffer2dataframe(buffer)
    df.basename = file_io.get_next_filename(settings["name"], settings["datadir"])
    df.name = f"{df.basename} @ {_runtime_vars['last-measurement']}"
    df.columns = ["Time [s]", "Voltage [V]"]
    return df

def save_csv():
    """
    Saves the contents of nvbuffer1 as .csv
    The settings 'datadir' and 'name' are used for determining the filepath:
    'datadir/nameXXX.csv', where XXX is the number of files that exist in datadir with the same name.
    """
    df = get_dataframe()
    filename = settings["datadir"] + "/" + df.basename + ".csv"
    df.to_csv(filename, index=False, header=True)
    print(f"Saved as '{filename}'")


def save_pickle():
    """
    Saves the contents of nvbuffer1 as .pkl
    The settings 'datadir' and 'name' are used for determining the filepath:
    'datadir/nameXXX.pkl', where XXX is the number of files that exist in datadir with the same name.
    """
    df = get_dataframe()
    filename = settings["datadir"] + "/" + df.basename + ".pkl"
    df.to_pickle(filename)
    print(f"Saved as '{filename}'")

def load_dataframe(p:str):
    """
    Load a dataframe from file.
    @param p : path of the file. If it has 'csv' extension, pandas.read_csv is used, pandas.read_pickle otherwise
    """
    if not path.isfile(p):
        print(f"ERROR: load_dataframe: File does not exist: {p}")
        return None
    if p.endswith(".csv"):
        df = pd.read_csv(p)
    else:
        df = pd.read_pickle(p)
    return df

def run_script(script_path):
    """
    Run a lua script on the Keithley device
    @param script_path : relative or absolute path to the .lua script
    """
    global k, settings
    if test:
        print("run_script: Test mode enabled, ignoring call to run_script")
    else:
        _keithley.run_lua(k, script_path=script_path)


def set(setting, value):
    global settings, config_path
    if setting in settings:
        if type(value) != type(settings[setting]):
            print(f"set: setting '{setting}' currently holds a value of type '{type(settings[setting])}'")
            return
    settings[setting] = value


def save_settings():
    with open(config_path, "w") as file:
        json.dump(settings, file, indent=4)

def load_settings():
    global settings, config_path
    with open(config_path, "r") as file:
        settings = json.load(file)
    settings["datadir"] = path.expanduser(settings["datadir"])

def help(topic=None):
    if topic == None:
        print("""
Functions:
    measure         - measure the voltage
    monitor         - measure the voltage with live monitoring in a matplotlib window
    save_csv        - save the last measurement as csv file
    save_pickle     - save the last measurement as pickled pandas dataframe
    load_dataframe  - load a pandas dataframe from csv or pickle 
    run_script      - run a lua script on the Keithely device
Run 'help(function)' to see more information on a function

Available topics:
    imports
    device
    settings
Run 'help("topic")' to see more information on a topic""")

    elif topic in [settings, "settings"]:
        print("""Settings:
    name: str       - name of the measurement, determines filename of 'save_csv'
    datadir: str    - output directory for the csv files
    interval: int   - interval (inverse frequency) of the measurements, in seconds
    beep: bool      - wether the device should beep or not

Functions:
    TODO set("setting", value)  - set a setting to a value
    TODO save_settings()        - store the settings as "k-teng.conf" in the working directory
    TODO load_settings()        - load settings from a file
    The global variable 'config_path' determines the path used by save/load_settings. Use -c '<path>' to set another path.
    The serach path is:
        <working-dir>/k-teng.json
        $XDG_CONFIG_HOME/k-teng.json
        ~/.config/k-teng.json
              """)
    elif topic == "imports":
        print("""Imports:
    numpy as np
    pandas as pd
    matplotlib.pyplot as plt
    os.path """)
    elif topic == "device":
        print("""Device:
    The opened pyvisa resource (Keithley device) is the global variable 'k'.
    You can interact using pyvisa functions, such as
    k.write("command"), k.query("command") etc. to interact with the device.""")
    else:
        print(topic.__doc__)


def init():
    global k, settings, test, config_path
    print(r""" ____  __.         ______________________ _______     ________
|    |/ _|         \__    ___/\_   _____/ \      \   /  _____/
|      <    ______   |    |    |    __)_  /   |   \ /   \  ___
|    |  \  /_____/   |    |    |        \/    |    \\    \_\  \
|____|__ \           |____|   /_______  /\____|__  / \______  /
        \/                            \/         \/         \/      1.0
Interactive Shell for TENG measurements with Keithley 2600B
---
Enter 'help()' for a list of commands""")
    from os import environ
    if path.isfile("k-teng.json"):
        config_path = "k-teng.json"
    elif 'XDG_CONFIG_HOME' in environ.keys():
        # and path.isfile(environ["XDG_CONFIG_HOME"] + "/k-teng.json"):
        config_path = environ["XDG_CONFIG_HOME"] + "/k-teng.json"
    else:
        config_path = path.expanduser("~/.config/k-teng.json")

    from sys import argv
    i = 1
    while i < len(argv):
        if argv[i] in ["-t", "--test"]:
            test = True
        elif argv[i] in ["-c", "--config"]:
            if i+1 < len(argv):
                config_path = argv[i+1]
            else:
                print("-c requires an extra argument: path of config file")
            i += 1
        i += 1


    if not path.isdir(path.dirname(config_path)):
        makedirs(path.dirname(config_path))

    if path.isfile(config_path):
        load_settings()

    if not path.isdir(settings["datadir"]):
        makedirs(settings["datadir"])

    if not test:
        from .keithley.keithley import init_keithley
        try:
            k = init_keithley(beep_success=settings["beep"])
        except Exception as e:
            print(e)
            exit()
    else:
        print("Running in test mode, device will not be connected.")


if __name__ == "__main__":
    init()