Generate nightly builds and json files (#357)

PR adds a nightly release pipeline.
Since the logic for the nightly build and release differs significantly
from the usual pipeline, I decided to put it in a separate file. The
same applies to the Python script that generates JSON files.

The nightly pipeline runs at 01:00 UTC every day, producing artefacts
and retaining them for 40 days if commits are made the day before it
runs.

cc https://github.com/paritytech/revive/issues/355
cc https://github.com/paritytech/devops/issues/4141

.github/scripts/json_generator_nightly.py

@@ -0,0 +1,155 @@
+#!/usr/bin/env python3
+"""
+This script generates JSON files for different platforms based on GitHub data.
+Requires the GITHUB_SHA, FIRST_SOLC_VERSION, LAST_SOLC_VERSION, TAG and FILEPATH environment variables to be set.
+Usage:
+    python json_generator_nightly.py
+"""
+import os
+import sys
+import json
+from datetime import datetime
+
+def validate_env_variables():
+    """Validate that environment variables are set."""
+    if "GITHUB_SHA" not in os.environ:
+        print("Error: GITHUB_SHA environment variable is not set.")
+        sys.exit(1)
+    if "FIRST_SOLC_VERSION" not in os.environ:
+        print("Error: FIRST_SOLC_VERSION environment variable is not set.")
+        sys.exit(1)
+    if "LAST_SOLC_VERSION" not in os.environ:
+        print("Error: LAST_SOLC_VERSION environment variable is not set.")
+        sys.exit(1)
+    if "TAG" not in os.environ:
+        print("Error: TAG environment variable is not set.")
+        sys.exit(1)
+    if "FILEPATH" not in os.environ:
+        print("Error: FILEPATH environment variable is not set.")
+        sys.exit(1)
+
+
+def fetch_data_file():
+    """
+    Fetch the data.json file with artifacts urls and sha256 checksums
+    and parse it into a single dictionary mapping artifact names to their URLs and SHAs.
+    """
+    # read data.json file
+    artifacts_data = {}
+    data_file_path = os.environ["FILEPATH"]
+    if not os.path.exists(data_file_path):
+        print("Error: data.json file not found.")
+        sys.exit(1)
+    with open(data_file_path, 'r') as f:
+        try:
+            artifacts_data = json.load(f)
+        except json.JSONDecodeError:
+            print("Error: data.json file is not a valid JSON.")
+            sys.exit(1)
+
+    result = {}
+
+    for item in artifacts_data:
+        for key, value in item.items():
+            if key.endswith('_url'):
+                base_key = key.rsplit('_url', 1)[0]
+                if base_key not in result:
+                    result[base_key] = {}
+                result[base_key]['url'] = value
+            elif key.endswith('_sha'):
+                base_key = key.rsplit('_sha', 1)[0]
+                if base_key not in result:
+                    result[base_key] = {}
+                result[base_key]['sha'] = value
+
+    return result
+
+
+
+
+
+def extract_build_hash():
+    """Extract the first 8 characters of the commit hash."""
+    sha = os.environ.get("GITHUB_SHA")
+    return f"commit.{sha[:8]}"
+
+def generate_asset_json_nightly(name, url, checksum):
+    """Generate JSON for a specific asset."""
+    # Date in format YYYY-MM-DD
+    date = datetime.now().strftime("%Y.%m.%d")
+    last_version = os.environ.get("TAG").replace('v','')
+    version = f"{last_version}-nightly.{date}"
+    SHA = os.environ.get("GITHUB_SHA", "")[:8]
+    build = f"commit.{SHA}"
+    long_version = f"{version}+{build}"
+
+    return {
+        "name": name,
+        "version": version,
+        "build": build,
+        "longVersion": long_version,
+        "url": url,
+        "sha256": checksum,
+        "firstSolcVersion": os.environ.get("FIRST_SOLC_VERSION"),
+        "lastSolcVersion": os.environ.get("LAST_SOLC_VERSION")
+    }
+
+def save_platform_json(platform_folder, asset_json):
+    """Save asset JSON and update list.json for a specific platform."""
+    # Create platform folder if it doesn't exist
+    os.makedirs(platform_folder, exist_ok=True)
+
+    # Update or create list.json
+    list_file_path = os.path.join(platform_folder, "list.json")
+
+    if os.path.exists(list_file_path):
+        with open(list_file_path, 'r') as f:
+            try:
+                list_data = json.load(f)
+            except json.JSONDecodeError:
+                list_data = {"builds": [], "releases": {}, "latestRelease": ""}
+    else:
+        list_data = {"builds": [], "releases": {}, "latestRelease": ""}
+
+    # Remove any existing entry with the same path
+    list_data['builds'] = [
+        build for build in list_data['builds']
+        if build['version'] != asset_json['version']
+    ]
+    # Add the new build
+    list_data['builds'].append(asset_json)
+
+    # Update releases
+    version = asset_json['version']
+    list_data['releases'][version] = f"{asset_json['name']}+{asset_json['longVersion']}"
+
+    # Update latest release
+    list_data['latestRelease'] = version
+
+    with open(list_file_path, 'w') as f:
+        json.dump(list_data, f, indent=4)
+
+def main():
+
+    validate_env_variables()
+    data = fetch_data_file()
+
+    # Mapping of asset names to platform folders
+    platform_mapping = {
+        'resolc-x86_64-unknown-linux-musl': 'linux',
+        'resolc-universal-apple-darwin': 'macos',
+        'resolc-x86_64-pc-windows-msvc': 'windows',
+        'resolc-web.js': 'wasm'
+    }
+
+    # Process each asset
+    for asset in data.keys():
+        platform_name = platform_mapping.get(asset)
+        if platform_name:
+            platform_folder = os.path.join(platform_name)
+            asset_json = generate_asset_json_nightly(asset, data[asset]['url'], data[asset]['sha'])
+            save_platform_json(platform_folder, asset_json)
+            print(f"Processed {asset} for {platform_name}")
+
+if __name__ == "__main__":
+    main()