#!/usr/bin/env python3
# args_json: {"type":"object","required":["path","content"],"properties":{"path":{"type":"string","description":"Absolute path to create or overwrite"},"content":{"type":"string","description":"File content to write"}}}
# ollie:prompt
# ## file_write
#
# Create or overwrite a file. Produces a unified diff.
#
# **Args**: `[path, content]`
#
# ```
# file_write(path="/abs/path", content="file content here")
# ```
#
# **Constraints**: Absolute paths only. Parent directory must exist.
# ollie:end

import sys
import os
import difflib

sys.path.insert(0, os.environ.get('OLLIE_TOOLS_PATH', os.path.dirname(os.path.abspath(__file__))))
from _lib.args import parse_args

def format_diff(path, old, new):
    old_lines = old.splitlines(keepends=True)
    new_lines = new.splitlines(keepends=True)
    return ''.join(difflib.unified_diff(old_lines, new_lines, fromfile=path, tofile=path))

args = parse_args()
file_path = args.require("path")
content = args.require("content")

if not os.path.isabs(file_path):
    print(f"STATUS=error STATE_CHANGED=false RETRYABLE=false")
    print(f"error: path must be absolute, got: {file_path}")
    sys.exit(1)

parent = os.path.dirname(file_path)
if parent and not os.path.isdir(parent):
    print(f"STATUS=error STATE_CHANGED=false RETRYABLE=false")
    print(f"error: parent directory does not exist: {parent}")
    sys.exit(1)

old_content = ""
if os.path.exists(file_path):
    try:
        with open(file_path, 'r', encoding='utf-8') as f:
            old_content = f.read()
    except UnicodeDecodeError:
        with open(file_path, 'r', encoding='utf-8', errors='replace') as f:
            old_content = f.read()

try:
    with open(file_path, 'w', encoding='utf-8') as f:
        f.write(content)
except OSError as e:
    print(f"STATUS=error STATE_CHANGED=false RETRYABLE=false")
    print(f"error: {e}")
    sys.exit(1)

diff = format_diff(file_path, old_content, content)
if not diff:
    print("STATUS=no_change STATE_CHANGED=false RETRYABLE=false")
    print("(no changes)")
else:
    print("STATUS=done STATE_CHANGED=true")
    print(diff, end="" if diff.endswith("\n") else "\n")