#!/usr/bin/env python3
#
# cust_pard.py --- Restarting the Model from PARDUMP
#                  See HYSPLIT Tutorial Sec. 16.2
#
# Change history:
# 24 Apr 2026 (BB) - standard-aligned, cross-platform version
# 16 Jun 2026 (SZ) - create image files 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 shutil
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 "cust_pard.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_TUTORIAL_DIRECTORY'

For Linux users (csh or tcsh shell):
   setenv TTR 'YOUR_HYSPLIT_TUTORIAL_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")


def find_met_dir(dat_name: str):
    env_override = os.environ.get("METDIR")
    candidates = []

    if env_override:
        candidates.append(Path(env_override))

    candidates += [
        wrk / "volcano",
        TTR / "volcano",
        TTR,
        PGM / "tutorial" / "volcano",
        PGM / "tutorial",
        OUT / "volcano",
        PGM / "met",
        PGM / "meteorology",
    ]

    for base in candidates:
        if base and (base / dat_name).exists():
            return base

    for root in [TTR, wrk, PGM]:
        try:
            for p in Path(root).rglob(dat_name):
                return p.parent
        except Exception:
            pass

    return None

# ---------- Mirror BAT variables ----------
wrk = OUT.parent
dat = "apr1420.bin"

met = find_met_dir(dat)
if met is None:
    print(f"ERROR: Meteorological file not found: {dat}")
    print("Set METDIR to the directory containing the file.")
    print("Example Windows: SET METDIR=C:\\Tutorial\\volcano")
    sys.exit(1)

# ASCDATA.CFG
with open(OUT / "ASCDATA.CFG", "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")
    f.write(f"'{PGM / 'bdyfiles'}{os.sep}'  directory of files       \n")

# Required restart files
if not (OUT / "PARDUMP").exists():
    print("ERROR: file PARDUMP is missing")
    print("Go back and run cust_volc.py first.")
    sys.exit(1)

# Recreate CONTROL1 block from cust_volc if missing
run, top = 12, 32000.0
odir = f".{os.sep}"

control1_lines = [
    f"{run}",
    "0",
    f"{top:.1f}",
    "1",
    f"{met}{os.sep}",
    f"{dat}",
    "4",
    "p006",
    "0.008E+16",
    "12.0",
    "00 00 00 00 00",
    "p020",
    "0.068E+16",
    "12.0",
    "00 00 00 00 00",
    "p060",
    "0.250E+16",
    "12.0",
    "00 00 00 00 00",
    "p200",
    "0.670E+16",
    "12.0",
    "00 00 00 00 00",
    "1",
    "45.0 0.0",
    "0.25 0.25",
    "90.0 360.0",
    odir,
    "volcano.bin",
    "1",
    "10000",
    "00 00 00 00 00",
    "00 00 00 00 00",
    "00 06 00",
    "4",
    "0.6 2.5 1.0",
    "0.0 0.0 0.0 0.0 0.0",
    "0.0 8.0E-05 8.0E-05",
    "0.0",
    "0.0",
    "2.0 2.5 1.0",
    "0.0 0.0 0.0 0.0 0.0",
    "0.0 8.0E-05 8.0E-05",
    "0.0",
    "0.0",
    "6.0 2.5 1.0",
    "0.0 0.0 0.0 0.0 0.0",
    "0.0 8.0E-05 8.0E-05",
    "0.0",
    "0.0",
    "20.0 2.5 1.0",
    "0.0 0.0 0.0 0.0 0.0",
    "0.0 8.0E-05 8.0E-05",
    "0.0",
    "0.0",
]

with open(OUT / "CONTROL1", "w", encoding="ascii") as f:
    f.write("\n".join(control1_lines) + "\n")

# SETUP.CFG
with open(OUT / "SETUP.CFG", "w", encoding="ascii") as f:
    f.write("&SETUP\n")
    f.write("kmsl = 0,\n")
    f.write("ninit = 1,\n")
    f.write("ndump = 12,\n")
    f.write("ncycl = 12,\n")
    f.write("numpar = 5000,\n")
    f.write("maxpar = 50000,\n")
    f.write("/\n")

def run_restart_case(syr, smo, sda, shr, hgt, title):
    lat, lon, lvl = 63.63, -19.62, 100.0

    with open(OUT / "CONTROL", "w", encoding="ascii") as f:
        f.write(f"{syr:02d} {smo:02d} {sda:02d} {shr:02d}\n")
        f.write("2\n")
        f.write(f"{lat:.2f} {lon:.2f} {lvl:.1f}\n")
        f.write(f"{lat:.2f} {lon:.2f} {hgt:.1f}\n")
        f.write("\n".join(control1_lines) + "\n")

    for fname in ["volcano.bin", "PARINIT", "parxplot.html"]:
        p = OUT / fname
        if p.exists():
            p.unlink()

    shutil.copyfile(OUT / "PARDUMP", OUT / "PARINIT")

    run_cmd([str(PGM / "exec" / f"hycs_std{exe_suffix}")], "Running hycs_std")

    with open(OUT / "LABELS.CFG", "w", encoding="ascii") as f:
        f.write(f"'TITLE&','### {Path(sys.argv[0]).name}: {title} ### &'\n")

    run_cmd([
        str(PGM / "exec" / f"parxplot{exe_suffix}"),
        "+g1",
        "-iPARDUMP",
        f"-j{PGM / 'graphics' / 'arlmap'}",
        "-k1",
        "-z80",
    ], "Plotting particles")

    html_file = OUT / "parxplot.html"
    if html_file.exists():
        new_html = OUT / f"parxplot_{shr}_{int(hgt)}.html"
        html_file.rename(new_html)

# First restart: eruption to 12 km
run_restart_case(
    syr=10,
    smo=4,
    sda=14,
    shr=12,
    hgt=12000.0,
    title="eruption to 12 km"
)

html_file = OUT / "parxplot_12_12000.html"
if html_file.exists():
    if DSP == "YES":
        webbrowser.open(str(html_file.resolve()))
    else:
        convert_html_to_img(str(html_file), [("part003.png",1)])

if DSP == "YES":
    input("Press Enter to continue...")

# Second restart: eruption to 6 km
run_restart_case(
    syr=10,
    smo=4,
    sda=15,
    shr=0,
    hgt=6000.0,
    title="eruption to 6 km"
)

html_file = OUT / "parxplot_0_6000.html"
if html_file.exists():
    if DSP == "YES":
        webbrowser.open(str(html_file.resolve()))
    else:
        convert_html_to_img(str(html_file), [("part005.png",1)])

print("\nScript completed successfully!")