#!/usr/bin/env python3
#
# traj_freq.py --- Run trajectory frequency analysis
#                  See HYSPLIT Tutorial Sec. 6.1
#
# Change history:
# 11 Aug 2025 (BB) - standard-aligned, cross-platform version
# 21 Aug 2025 (SZ) - add a pause between plots when DSP is set to "YES."
#                  - create image files when DSP=NO.
#                  - use backward slash as directory separator for Windows PC.
#                  - show help messages when HYSPLIT or Tutorial is not found.
#                  - correct LABELS.CFG file 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)

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 "traj_freq.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: Tutorial directory 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")


# Cleanup
for f in Path(".").glob("fdump.*"):
    f.unlink()
if (OUT / "ASCDATA.CFG").exists():
    (OUT / "ASCDATA.CFG").unlink()

# Write ASCDATA.CFG
with open("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")

# Parameters
syr, smo = 83, 9
lat, lon, lvl = 39.90, -84.22, 600.0
run, top = 48, 10000.0
met = TTR / "captex"
dat = "RP198309.gbl"

# Main CONTROL generation loop
infile_list = []
for day in range(1, 29 + 1):
    for hour in ("00", "06", "12", "18"):
        dstr = f"{day:02d}"
        ctl_name = f"fdump{syr:02d}{smo:02d}{dstr}{hour}"
        infile_list.append(ctl_name)

        with open("CONTROL", "w", encoding="ascii") as ctl:
            ctl.write(f"{syr:02d} {smo:02d} {dstr} {hour}\n")
            ctl.write("1\n")
            ctl.write(f"{lat} {lon} {lvl}\n")
            ctl.write(f"{run}\n")
            ctl.write("0\n")
            ctl.write(f"{top}\n")
            ctl.write("1\n")
            ctl.write(f"{met}{os.sep}\n")
            ctl.write(f"{dat}\n")
            ctl.write(f".{os.sep}\n")
            ctl.write(f"{ctl_name}\n")

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

# Write INFILE
with open("INFILE", "w", encoding="ascii") as f:
    for name in infile_list:
        f.write(f"{name}\n")

# Frequency analysis pass 1
run_cmd([str(PGM / "exec" / f"trajfreq{exe_suffix}"),
         "-ftfreq.bin", "-g1.0", "-iINFILE", "-r0", "-s0:99999"],
         "Running trajfreq pass 1")

# Create LABELS.CFG
with open("LABELS.CFG", "w", encoding="ascii") as f:
    f.write("'TITLE&','### traj_freq.py ### &'\n")
    f.write("'MAPID&',' Values &'\n")
    f.write("'UNITS&',' %&'\n")
    f.write("'VOLUM&',' &'\n")

# Plot pass 1
run_cmd([str(PGM / "exec" / f"concplot{exe_suffix}"),
         "+g1", "-m0", "-k1", "-z80",
         f"-j{PGM / 'graphics' / 'arlmap'}", "-itfreq.bin"],
         "Running concplot pass 1")

if DSP == "YES":
    webbrowser.open("concplot.html")
    input("Press Enter to continue ...")
else:
    convert_html_to_img("concplot.html", [("freq010.png",1)])

# Frequency analysis pass 2
run_cmd([str(PGM / "exec" / f"trajfreq{exe_suffix}"),
         "-ftfreq.bin", "-g1.0", "-iINFILE", "-r1", "-s0:99999"],
         "Running trajfreq pass 2")

# Plot pass 2
run_cmd([str(PGM / "exec" / f"concplot{exe_suffix}"),
         "+g1", "-m0", "-k1", "-z80",
         f"-j{PGM / 'graphics' / 'arlmap'}", "-itfreq.bin"],
         "Running concplot pass 2")

if DSP == "YES":
    webbrowser.open("concplot.html")
else:
    convert_html_to_img("concplot.html", [("freq011.png",1)])

print("\nScript completed successfully.")