#!/usr/bin/env python3
#
# traj_basic.py --- run HYSPLIT trajectory and show trajectory.
#                   See HYSPLIT Tutorial Sec 4.1
#
# Change history:
# 10 Jun 2025 (BB) - initial, cross-platform version
# 12 Jun 2025 (SZ) - directories from command-line args or from environment varibles
#                  - create png image when DSP=NO
# 15 Jun 2025 (BB) - condensed code, combined functions
# 16 Jun 2025 (SZ) - bug fix with creating png for Linux/macOS.
# 21 Aug 2025 (SZ) - correct LABELS.CFG content.
# 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)

# Detect OS and set paths
system = platform.system().lower()
if system == "windows":
    PGM = Path(sys.argv[1]) if len(sys.argv) >= 2 else Path("C:\\hysplit")
    OUT = Path(sys.argv[2]) if len(sys.argv) >= 3 else PGM / "working"
    DSP = sys.argv[3] if len(sys.argv) >= 4 else "YES"
    TTR = Path(os.environ.get("TTR", "C:\\Tutorial"))
    exe_suffix = ".exe"
else:
    PGM = Path(sys.argv[1]) if len(sys.argv) >= 2 else Path.home() / "hysplit"
    OUT = Path(sys.argv[2]) if len(sys.argv) >= 3 else PGM / "working"
    DSP = sys.argv[3] if len(sys.argv) >= 4 else "YES"
    TTR = Path(os.environ.get("TTR", Path.home() / "Tutorial"))
    exe_suffix = ""

# Check paths
if not PGM.exists():
    script = Path(__file__).name if "__file__" in globals() else "traj_basic.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")


# Create ASCDATA.CFG
ascdata_cfg = OUT / "ASCDATA.CFG"
ascdata_cfg.unlink(missing_ok=True)
with ascdata_cfg.open("w") 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")

# Constants
syr, smo, sda, shr = 83, 9, 25, 17
lat, lon, lvl = 39.90, -84.22, 10.0
run, top = 68, 10000.0
met = TTR / "captex"
dat = "captex2_wrf27uw.bin"

met_file = met / dat
if not met_file.exists():
    print(f"ERROR: Meteorological data not found at {met_file}")
    print("Please adjust the HYSPLIT Tutorial path for your system")
    sys.exit(1)

# Write CONTROL file
with (OUT / "CONTROL").open("w", encoding="ascii") as f:
    f.write(f"{syr} {smo} {sda} {shr}\n")
    f.write("1\n")
    f.write(f"{lat} {lon} {lvl}\n")
    f.write(f"{run}\n")
    f.write("0\n")
    f.write(f"{top}\n")
    f.write("1\n")
    f.write(f"{met}{os.sep}\n")
    f.write(f"{dat}\n")
    f.write(f".{os.sep}\n")
    f.write("tdump\n")

# Remove old files
for filename in ["tdump", "SETUP.CFG"]:
    (OUT / filename).unlink(missing_ok=True)

# Run HYSPLIT
run_cmd([str(PGM / "exec" / f"hyts_std{exe_suffix}")], "Running HYSPLIT")

# Create LABELS.CFG
with (OUT / "LABELS.CFG").open("w", encoding="ascii") as f:
    f.write(f"'TITLE&','### {Path(__file__).name} ###&'\n")

# Run trajplot
run_cmd([str(PGM / "exec" / f"trajplot{exe_suffix}"), "+g1", "-itdump", "-v0",
         "-z50", f"-j{PGM / 'graphics' / 'arlmap'}"], "Generating plot")

# Display plot
html_file = OUT / "trajplot.html"
if html_file.exists():
    if DSP == "YES":
        webbrowser.open(str(html_file))
        print(f"Plot opened: {html_file}")
    else:
        convert_html_to_img(str(html_file), [("traj008.png", 1)])
else:
    print("Warning: trajplot.html not generated")

print("Script completed successfully!")