#!/usr/bin/env python3
#
# ens_meteo.py --- Meteorological Grid Ensemble
#                  See HYSPLIT Tutorial Sec. 12.1
#
# Change history:
# 09 Dec 2025 (BB) - standard-aligned, cross-platform version
# 09 Jan 2025 (SZ) - minor edits for style consistency
#                  - create images when DSP=NO
# 18 Jun 2026 (SZ) - standardize code for run_cmd(), convert_html_to_img(),
#                    etc. across Python scripts
#                  - ensure encoding is specified when opening files

import os
import sys
import platform
from pathlib import Path
import subprocess
import webbrowser

if sys.version_info < (3, 8):
    print("Please use Python 3.8 or higher.")
    sys.exit(1)


system = platform.system().lower()
if system == "windows":
    PGM = Path(sys.argv[1]) if len(sys.argv) > 1 else Path("C:\\hysplit")
    OUT = Path(sys.argv[2]) if len(sys.argv) > 2 else PGM / "working"
    DSP = sys.argv[3] if len(sys.argv) > 3 else "YES"
    TTR = Path(os.environ.get("TTR", "C:\\Tutorial"))
    exe_suffix = ".exe"
else:
    PGM = Path(sys.argv[1]) if len(sys.argv) > 1 else Path.home() / "hysplit"
    OUT = Path(sys.argv[2]) if len(sys.argv) > 2 else PGM / "working"
    DSP = sys.argv[3] if len(sys.argv) > 3 else "YES"
    TTR = Path(os.environ.get("TTR", Path.home() / "tutorial"))
    exe_suffix = ""

if not PGM.exists():
    script = Path(__file__).name if "__file__" in globals() else "ens_meteo.py"
    print(f"ERROR: HYSPLIT not found at {PGM}")
    print(f"""
Please specify the path to your HYSPLIT installation using a command-line argument:

python {script} YOUR_HYSPLIT_DIRECTORY [OUT] [DSP (YES|NO)]

Example:
    python {script} C:\\hysplit C:\\hysplit\\working YES
""")
    sys.exit(1)

if not TTR.exists():
    print(f"ERROR: HYSPLIT tutorial not found at {TTR}")
    print("""
Please set the TTR environment variable to point to your HYSPLIT tutorial directory.

For Windows users (Command Prompt):
   SET TTR=YOUR_HYSPLIT_TUTORIAL_DIRECTORY

For Linux users (bash shell):
   export TTR='YOUR_HYSPLIT_TOTURIAL_DIRECTORY'

For Linux users (csh or tcsh shell):
   setenv TTR 'YOUR_HYSPLIT_TOTURIAL_DIRECTORY'""")
    sys.exit(1)

os.chdir(OUT)


# ------------------------------------------------------------------
# Helper functions
# ------------------------------------------------------------------

def run_cmd(cmd, desc="", allow_fail=False, stdout_file=None, append=False):
    if desc:
        print(f"{desc}...")

    exitcode = 0
    with subprocess.Popen(cmd,
                         stdout=subprocess.PIPE,
                         stderr=subprocess.STDOUT,
                         text=True) as p:
        if stdout_file:
            mode="a" if append else "w"
            with open(stdout_file, mode, encoding="utf-8") as f_out:
                for ln in p.stdout:
                    print(ln, end="")
                    f_out.write(ln)
        else:
            with p.stdout as f:
                for ln in iter(f.readline, b'\n'):
                    if len(ln) == 0:
                        break
                    print(ln.rstrip())

        done = False
        while not done:
            try:
                exitcode = p.wait(timeout=1)
                done = True
            except subprocess.TimeoutExpired:
                print("WARN: subprocess timed out.")

    if exitcode != 0:
        if allow_fail:
            print(f"WARN: command failed with exit code {exitcode} -> {' '.join(cmd)}")
        else:
            print(f"ERROR: command failed with exit code {exitcode} -> {' '.join(cmd)}")
            sys.exit(1)


def convert_html_to_img(html_file, img_name_frame_nums):
    # Split SVG into Linux-consistent naming: F00-sec71_001.svg, etc.
    temp_img_name = "temp"
    run_cmd([str(PGM / "exec" / f"splitsvg{exe_suffix}"),
             f"-i{html_file}", f"-o{temp_img_name}.svg"])

    # Locate ImageMagick for cross-platform conversion
    if system == "windows":
        convert_exe = None
        imgk_dir = next(
            (k for k in os.environ.get('PATH', '').split(os.pathsep)
             if "ImageMagick" in k),
            None
        )
        if imgk_dir:
            # Use magick.exe for ImageMagick 7.x and later. Use convert.exe for earlier versions.
            for cmd in ('magick', 'convert'):
                candidate = os.path.join(imgk_dir, f'{cmd}{exe_suffix}')
                if os.path.exists(candidate):
                    convert_exe = candidate
                    break
    else:
        convert_exe = "convert"

    if convert_exe:
        # Match Linux naming for DSP=NO mode exactly
        for img_name, frame_num in img_name_frame_nums:
            svg = Path(f"F{frame_num:02d}-{temp_img_name}.svg")
            run_cmd([convert_exe, str(svg), img_name])
            print(f"Converted {svg} -> {img_name}")
            svg.unlink()
    else:
        print("ImageMagick not found — skipping .svg conversion")


# ----------------------------------------------------------------------
# Script-specific helpers (lowercase names required)
# ----------------------------------------------------------------------

map_path = PGM / "graphics" / "arlmap"
inp = "ensemble"
met = TTR / "captex"
dat = "captex2_wrf27uw.bin"


def write_ascdata():
    asc = OUT / "ASCDATA.CFG"
    if asc.exists():
        asc.unlink()

    with asc.open("w", encoding="ascii") as f:
        f.write("-90.0   -180.0  lat/lon of lower left corner\n")
        f.write("1.0     1.0     lat/lon spacing in degrees\n")
        f.write("180     360     lat/lon number of data points\n")
        f.write("2               default land use category\n")
        f.write("0.2             default roughness length (m)\n")
        # Required: last line path MUST have single quotes
        f.write(f"'{PGM / 'bdyfiles'}{os.sep}'  directory of files\n")


def write_control():
    control = OUT / "CONTROL"
    if control.exists():
        control.unlink()

    # All lowercase internal variables
    syr, smo, sda, shr = 83, 9, 25, 17
    lat, lon, lvl = 39.90, -84.22, 200.0
    run_hours = 49
    top = 10000.0

    with control.open("w", encoding="ascii") as f:
        f.write(f"{syr:02d} {smo:02d} {sda:02d} {shr:02d}\n")
        f.write("1\n")
        f.write(f"{lat:.2f} {lon:.2f} {lvl:.1f}\n")
        f.write(f"{run_hours}\n")
        f.write("0\n")
        f.write(f"{top:.1f}\n")
        f.write("1\n")
        f.write(f"{met}{os.sep}\n")
        f.write(f"{dat}\n")
        f.write("1\n")
        f.write("PMCH\n")
        f.write("67000.0\n")
        f.write("3.0\n")
        f.write("00 00 00 00 00\n")
        f.write("1\n")
        f.write("42.0 -78.0\n")
        f.write("0.25 0.25\n")
        f.write("15.0 25.0\n")

        # Required: output directory must use os.sep
        f.write(f".{os.sep}\n")

        f.write(f"{inp}\n")
        f.write("1\n")
        f.write("100\n")
        f.write("83 09 26 06 00\n")
        f.write("83 09 28 15 00\n")
        f.write("00 03 00\n")
        f.write("1\n")
        f.write("0.0 0.0 0.0\n")
        f.write("0.0 0.0 0.0 0.0 0.0\n")
        f.write("0.0 0.0 0.0\n")
        f.write("0.0\n")
        f.write("0.0\n")


def write_setup():
    setup = OUT / "SETUP.CFG"
    if setup.exists():
        setup.unlink()

    with setup.open("w", encoding="ascii") as f:
        f.write("&SETUP\n")
        f.write("numpar = 5000,\n")
        f.write("maxpar = 100000,\n")
        f.write("/\n")


def clean_member_files():
    first = OUT / f"{inp}.001"
    if first.exists():
        for fpath in OUT.glob(f"{inp}.*"):
            try:
                fpath.unlink()
            except OSError as e:
                print(f"WARNING: could not delete {fpath}: {e}")


def run_members():
    exe = PGM / "exec" / f"hycs_ens{exe_suffix}"
    for m in range(1, 28):
        run_cmd(
            [str(exe), str(m)],
            desc=f"hycs_ens member {m}"
        )


def run_conprob():
    exe = PGM / "exec" / f"conprob{exe_suffix}"
    run_cmd(
        [str(exe), "-bensemble", "-t1", "-p1", "-z1"],
        desc="Run conprob"
    )


def write_labels():
    labels = OUT / "LABELS.CFG"
    with labels.open("w", encoding="ascii") as f:
        f.write("'TITLE&','### ens_disp.py ### &'\n")
        f.write("'UNITS&',' g&'\n")
        f.write("'MAPID&','Air Concentration&'\n")


def make_plot(html_name, exe_name, args, img_name_frame_nums):
    """Generic HYSPLIT plot routine with DSP=NO fallback."""
    html_path = OUT / html_name
    if html_path.exists():
        html_path.unlink()

    exe = PGM / "exec" / f"{exe_name}{exe_suffix}"
    run_cmd([str(exe)] + args, desc=f"Create {html_name}")

    if DSP.upper() == "YES":
        webbrowser.open(html_path.as_uri())
        input("Press Enter to continue ...")
    else:
        convert_html_to_img(html_name, img_name_frame_nums)


# ----------------------------------------------------------------------
# MAIN
# ----------------------------------------------------------------------
def main():
    print("=== HYSPLIT Tutorial Sec. 12.1: Ensemble Dispersion ===")
    print(f"PGM: {PGM}")
    print(f"OUT: {OUT}")
    print(f"TTR: {TTR}")
    print(f"DSP: {DSP}")

    write_ascdata()
    write_control()
    write_setup()
    clean_member_files()
    run_members()
    run_conprob()
    write_labels()

    make_plot("concplot.html", "concplot",
              ["+g1", "-iprob50", f"-j{map_path}", "-m0", "-k1", "-z80"],
              [("emet008.png", 4)])

    make_plot("boxplots.html", "boxplots",
              ["+g1", "-x-78.80", "-y42.25"],
              [("emet011.png", 1)])

    make_plot("ensplots.html", "ensplots",
              ["+g1", "-bensemble", "-x-78.80", "-y42.25"],
              [("emet012.png", 1)])

    print("Done. All HTML (and PNG) outputs written to working directory.")


if __name__ == "__main__":
    main()