#!/usr/bin/env python3
#
# src_fwrd.py --- Emissions from a Known Location
#                 See HYSPLIT Tutorial Sec. 13.1
#
# Change history:
# 18 Oct 2025 (BB) - standard-aligned, cross-platform version
# 12 Feb 2026 (SZ) - minor edits for style consistency
#                  - 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 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 "src_fwrd.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")


# -------------------------------------------------------------------
# static inputs
# -------------------------------------------------------------------
wrk = TTR
inp = "hysplit2.bin"

met_dir = wrk / "captex"
met_file = "captex2_wrf27uw.bin"
obs_file = met_dir / "captex2_3hr.txt"

lat = 39.90
lon = -84.22
lvl = 10.0
top = 10000.0

# -------------------------------------------------------------------
# ASCDATA.CFG
# -------------------------------------------------------------------
with open("ASCDATA.CFG", "w", encoding="ascii") as f:
    f.write(
        "-90.0   -180.0\n"
        "1.0     1.0\n"
        "180     360\n"
        "2\n"
        "0.2\n"
        f"'{PGM / 'bdyfiles'}{os.sep}'  directory of files\n"
    )


def write_setup():
    with open("SETUP.CFG", "w", encoding="ascii") as f:
        f.write("&SETUP\n")
        f.write(" numpar = 50000,\n")
        f.write(" maxpar = 100000,\n")
        f.write("/\n")


def write_control(start_hour, run_hours, cmin, cmax):
    with open("CONTROL", "w", encoding="ascii") as f:
        f.write(f"83 09 25 {start_hour:02d}\n")
        f.write("1\n")
        f.write(f"{lat} {lon} {lvl}\n")
        f.write(f"{run_hours}\n")
        f.write("0\n")
        f.write(f"{top}\n")
        f.write("1\n")
        f.write(f"{met_dir}{os.sep}\n")
        f.write(f"{met_file}\n")
        f.write("1\n")
        f.write("PMCH\n")
        f.write(f"{cmin}\n")
        f.write(f"{cmax}\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")
        f.write(f".{os.sep}\n")
        f.write(f"{inp}\n")
        f.write("1\n")
        f.write("100\n")
        f.write("83 09 25 18 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 run_case(start_hour, run_hours, cmin, cmax):
    if Path(inp).exists():
        Path(inp).unlink()

    write_control(start_hour, run_hours, cmin, cmax)
    write_setup()

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

    run_cmd([
        str(PGM / "exec" / f"c2datem{exe_suffix}"),
        "-xi",
        f"-i{inp}",
        "-ohysplit.txt",
        "-c1.0E+12",
        f"-m{obs_file}"
    ], "Converting concentration to data")

    run_cmd([
        str(PGM / "exec" / f"statmain{exe_suffix}"),
        "-t0",
        "-rhysplit.txt",
        f"-d{obs_file}",
        "-l10.0",
        "-o1"
    ], "Running statistics")

    with open("statA.txt", "r", encoding="ascii", errors="ignore") as file:
        print(file.read())


# -------------------------------------------------------------------
# run 1 (17Z)
# -------------------------------------------------------------------
run_case(start_hour=17, run_hours=19, cmin=67000.0, cmax=3.0)

with open("LABELS.CFG", "w", encoding="ascii") as f:
    f.write("'TITLE&','### conc_captex_stat ### &'")

if DSP.upper() == "YES":
    input("Press Enter to display statistics plot...")

run_cmd([
    str(PGM / "exec" / f"scatter{exe_suffix}"),
    "+g1",
    "-idataA.txt",
    "-p10.0"
], "Generating scatter plot")

html = Path("scatter.html")
if html.exists():
    if DSP.upper() == "YES":
        try:
            webbrowser.open(html.resolve().as_uri())
        except Exception as e:
            print(f"WARNING: could not open {html} in web browser: {e}")
    else:
        convert_html_to_img(str(html), [("fwd001.png",1)])

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

# -------------------------------------------------------------------
# run 2 (15Z)
# -------------------------------------------------------------------
run_case(start_hour=15, run_hours=21, cmin=1.0, cmax=21.0)