#!/usr/bin/env python3

import sys
import subprocess
import tempfile
import os

# Force temp files into a folder inside your project (fully owned by you)
custom_temp_dir = os.path.join(os.getcwd(), "tmp")
os.makedirs(custom_temp_dir, exist_ok=True)
tempfile.tempdir = custom_temp_dir

SRCLIB = "src"
JCLLIB = "jcl"
MVSHOST = "oldcomputernerd.com"
RDRPORT = 3505
MVS_PASSWORD = os.environ.get("MVS_BATCH_PASSWORD")


def create_jcl_payload(local_file, dataset_name, member_name): 
    
    with open(local_file, 'r') as f:
        sysin = f.readlines()

    # PDS member: Use IEBUPDTE
    jcl = f"""
//UPLOAD   JOB (ACCT),'UPLOAD',
//             USER=@05054,PASSWORD={MVS_PASSWORD},
//             CLASS=A,MSGCLASS=H,NOTIFY=@05054
//COPY     EXEC PGM=IEBUPDTE,PARM=NEW
//SYSPRINT DD SYSOUT=*
//SYSUT1   DD DUMMY
//SYSUT2   DD DSN={dataset_name},DISP=MOD,UNIT=SYSDA,
//            DCB=(RECFM=FB,LRECL=80,BLKSIZE=0)
//SYSIN    DD *
"""
    # Append control statement, source lines, end, and terminator (no leading space on ./)
    jcl += f"./ ADD NAME={member_name}\n"
    for line in sysin:
        line = line.rstrip('\n')[:80]
        jcl += line.ljust(80) + "\n"
    jcl += "./ ENDUP\n"
    jcl += "/*\n"
    
    return jcl


def upload_source(local_file, dataset_name, member_name, mvshost=MVSHOST):
    """Upload source code to MVS PDS member"""

    # Read the source file
    # full path will come from the job runner
    # filepath = os.path.join(SRCLIB, local_file)
    payload = create_jcl_payload(local_file, dataset_name, member_name)
    
    # Write JCL to temporary file and submit via netcat
    
    with tempfile.NamedTemporaryFile(mode='w', delete=False, suffix='.jcl') as tmpfile:
        tmpfile.write(payload)
        tmpfile.flush()
        tmpfile_path = tmpfile.name
    try:
        with open(tmpfile_path, 'rb') as f:
            subprocess.run(
                ['nc', '-w', '5', mvshost, str(RDRPORT)],
                input=f.read(),
                check=True,
                capture_output=True
            )
        print(f"Uploaded {local_file} to {dataset_name}({member_name})")
        return 0
    except subprocess.CalledProcessError as e:
        print(f"Upload failed: {e}")
        print("stderr:", e.stderr.decode(errors='ignore'))
        return 1
    
    finally:
        # Clean up outside
        os.unlink(tmpfile_path)

def submit_jcl(job, mvshost="oldcomputernerd.com"):
    """Submit JCL job from local directory"""
    subjcl = os.path.join(JCLLIB, f"{job.upper()}.jcl")

    if not os.path.exists(subjcl):
        print(f"JCL file {subjcl} not found")
        return 1

    subcmd = f"nc -w 5 {mvshost} {RDRPORT} < {subjcl}"

    try:
        subprocess.run(subcmd, shell=True, check=True)
        print(f"Submitted JCL job: {job}")
        return 0
    except subprocess.CalledProcessError as e:
        print(f"JCL submission failed: {e}")
        return 1

if __name__ == "__main__":
    if len(sys.argv) < 2:
        print("Usage: mvs_job.py <local_source_file> [destination_pds] [mvshost]")
        print()
        print("Arguments:")
        print("  local_source_file  - Path to source file (required)")
        print("  destination_pds    - PDS destination as DATASET(MEMBER) (optional)")
        print("                       Default: @05054.C90.SOURCE(basename)")
        print("  mvshost           - MVS host (optional, default: oldcomputernerd.com)")
        print()
        print("Examples:")
        print("  mvs_job.py src/sieve11.c")
        print("  mvs_job.py src/sieve11.c '@05054.C90.SOURCE(SIEVE11)'")
        print("  mvs_job.py src/hello.c '@05054.C90.SOURCE(HELLO)' mainframe.example.com")
        print()
        print("Notes:")
        print("  - JCL file is assumed to be jcl/<basename>.jcl")
        print("  - Member name defaults to source filename without extension")
        sys.exit(1)

    local_file = sys.argv[1]

    # Extract base name without extension for defaults
    basename = os.path.splitext(os.path.basename(local_file))[0].upper()
    valid_host_source_pds_suffixes = ['C', 'ALG', 'ASM', 'BAS', 'COB', 'PAS', 'PL360']
    default_suffix = valid_host_source_pds_suffixes[0]

    # Parse destination PDS (optional second argument)
    if len(sys.argv) > 2 and sys.argv[2]:
        destination = sys.argv[2]
        # Parse PDS syntax: DATASET(MEMBER)
        if '(' in destination and destination.endswith(')'):
            dataset_name = destination[:destination.index('(')]
            member_name = destination[destination.index('(')+1:-1]
        else:
            print(f"Error: Invalid PDS syntax '{destination}'. Use format: DATASET(MEMBER)")
            sys.exit(1)
    else:
        # Default destination
        dataset_name = f"@05054.SRCLIB.{default_suffix}"
        member_name = basename

    # JCL job name defaults to basename
    job = basename.lower()

    # Optional host override
    mvshost = sys.argv[3] if len(sys.argv) > 3 else MVSHOST

    print(f"Source: {local_file}")
    print(f"Destination: {dataset_name}({member_name})")
    print(f"JCL: jcl/{job}.jcl")
    print(f"Host: {mvshost}")
    print()

    # Step 1: Upload source to PDS
    if upload_source(local_file, dataset_name, member_name, mvshost) != 0:
        sys.exit(1)

    # Step 2: Submit JCL job
    submit_jcl(job, mvshost)