# Copyright 2024 The Pigweed Authors
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy of
# the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under
# the License.
"""Plot ADC updates as an SVG from a device logfile."""

import argparse
from datetime import datetime
from datetime import timedelta
import logging
from pathlib import Path
import sys

import pw_cli.log

from gonk_tools.gonk import DEFAULT_CSV_LOGFILE
from gonk_tools.adc import (
    get_channel_names,
    ADC_COUNT,
)


import matplotlib.pyplot as plt
import numpy as np

_LOG = logging.getLogger(__package__)


def _parse_args():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument(
        '-i',
        '--input-csv',
        type=Path,
        default=Path(DEFAULT_CSV_LOGFILE),
        help=f'Input CSV text file. Default: {DEFAULT_CSV_LOGFILE}',
    )
    parser.add_argument(
        '-o',
        '--output-svg',
        type=Path,
        default=None,
        help='Output svg file.',
    )
    return parser.parse_args()


def plot(
    input_csv: Path,
    output_svg: Path,
) -> int:
    """Plot ADC values."""
    # pylint: disable=too-many-locals
    pw_cli.log.install()

    print(f'Input CSV: {input_csv}')
    if output_svg:
        print(f'Output svg file: {output_svg}')

    interactive_plotting = not (output_svg)
    if interactive_plotting:
        print('No outputs specified; plotting interactively')

    start_time: datetime | None = None
    time_values = []
    vbus_values: list[list[float]] = []
    vshunt_values: list[list[float]] = []
    power_values: list[list[float]] = []
    channel_names = get_channel_names()

    for i in range(ADC_COUNT):
        vbus_values.append([])
        vshunt_values.append([])
        power_values.append([])

    with input_csv.open() as f:
        current_time = datetime.now()

        for line in f.readlines():
            parts = [line.strip() for line in line.split(',')]
            if len(parts) != ADC_COUNT * 3 + 2:
                _LOG.error('Unexpected number of CSV fields: %i', len(parts))
                _LOG.error('Fields: %s', parts)
                _LOG.error('Line: "%s"', line)

            # Extract the host timestamp
            dtstr = parts[0]
            dt = datetime.strptime(dtstr, '%Y%m%d %H:%M:%S.%f')
            # Extract delta_micros
            delta_micros = int(parts[1])

            # Set start timestamp if not found already.
            if not start_time:
                start_time = dt
                current_time = start_time - timedelta(microseconds=delta_micros)

            # Increment delta_micros
            current_time += timedelta(microseconds=delta_micros)

            # Save the timestamp
            time_values.append((current_time - start_time).total_seconds())

            index = 2
            voltages = list(float(i) for i in parts[index : index + ADC_COUNT])
            index += ADC_COUNT
            current = list(float(i) for i in parts[index : index + ADC_COUNT])
            index += ADC_COUNT
            power = list(float(i) for i in parts[index : index + ADC_COUNT])

            for i, voltage in enumerate(voltages):
                vbus_values[i].append(voltage)
                vshunt_values[i].append(current[i])
                power_values[i].append(power[i])

    # Plot vbus and vshunt values.
    _fig, (ax1, ax2, ax3) = plt.subplots(  # type: ignore
        3, 1, layout='constrained', figsize=[11.67, 8.27]
    )

    times = np.asarray(time_values)
    ax1.set_xlabel('Time (s)')
    ax2.set_xlabel('Time (s)')
    ax3.set_xlabel('Time (s)')

    linewidth = 0.7
    ax1.set_ylabel('vbus')
    for i in range(ADC_COUNT):
        ax1.plot(
            times,
            np.asarray(vbus_values[i]),
            label=channel_names[i],
            linestyle='solid',
            linewidth=linewidth,
        )

    ax2.set_ylabel('Ishunt')
    for i in range(ADC_COUNT):
        ax2.plot(
            times,
            np.asarray(vshunt_values[i]),
            label=channel_names[i],
            linestyle='solid',
            linewidth=linewidth,
        )
    ax3.set_ylabel('Power')
    for i in range(ADC_COUNT):
        ax3.plot(
            times,
            np.asarray(power_values[i]),
            label=channel_names[i],
            linestyle='solid',
            linewidth=linewidth,
        )

    ax1.legend()
    ax1.grid(True)
    ax2.legend()
    ax2.grid(True)
    ax3.legend()
    ax3.grid(True)

    if output_svg:
        plt.savefig(output_svg)

    if interactive_plotting:
        plt.show()

    return 0


def main() -> None:
    sys.exit(plot(**vars(_parse_args())))


if __name__ == '__main__':
    main()