#!/usr/bin/env python3

"""
This scripts checks the metadata.json against a set of rules for allowed
values.  This allows degradation in results to be flagged as an error
in the build.

The rules file has the form
{
   "rules": [
       {
           "field" : "<name>",
           "value" : <numeric_value>,
           "compare": "<operator>"
       }, ...
   ]
}

field is the name of a field in the metadata file
value is the reference value to compare to
operator can be one of "<", ">", "<=", ">=", "==", "!=".
The value is converted to a float for comparison if possible
"""

from os.path import isfile
import argparse
import json
import operator
import sys

parser = argparse.ArgumentParser(
    description="Checks metadata from OpenROAD flow against a set of rules"
)
parser.add_argument("--metadata", "-m", required=True, help="The metadata file")
parser.add_argument("--rules", "-r", required=True, nargs="+", help="The rules file")
parser.add_argument(
    "--only-prefix",
    nargs="+",
    default=None,
    help="Check only rules whose field starts with one of these prefixes. "
    "Lets a partial run (e.g. synthesis-only) be gated by a full-flow "
    "rules file without tripping the missing-field error.",
)
args = parser.parse_args()

with open(args.metadata) as metadataFile:
    metadata = json.load(metadataFile)

rules = dict()
for filePath in args.rules:
    if isfile(filePath):
        with open(filePath) as rulesFile:
            rules.update(json.load(rulesFile))
    else:
        print(f"[WARN] File {filePath} not found")

if args.only_prefix:
    rules = {
        field: rule
        for field, rule in rules.items()
        if any(field.startswith(prefix) for prefix in args.only_prefix)
    }

if len(rules) == 0:
    print("No rules")
    sys.exit(1)


def try_number(string):
    """
    Convert to a float if possible
    """
    try:
        return float(string)
    except ValueError:
        return string


ops = {
    "<": operator.lt,
    ">": operator.gt,
    "<=": operator.le,
    ">=": operator.ge,
    "==": operator.eq,
    "!=": operator.ne,
}

ERRORS = 0
WARNS = 0

# Check for new warnings
for field, build_value in metadata.items():
    if field not in rules.keys() and "__warnings__count:" in field:
        print(f"[WARN] {field} fail test: {build_value} (New warning)")
        WARNS += 1

# Check for rules
for field, rule in rules.items():
    compare = rule["compare"]
    op = ops[compare]
    rule_value = try_number(rule["value"])

    if field in metadata.keys():
        build_value = try_number(metadata[field])
    elif "__warnings__count:" in field:
        # Metric is a warning count. If the value is missing,
        # there were zero warnings
        build_value = 0.0
    else:
        print(f"[ERROR] Value not found for {field}.")
        sys.exit(1)

    # Convert to integer if possible
    if isinstance(rule_value, float) and rule_value.is_integer():
        rule_value = int(rule_value)
    if isinstance(build_value, float) and build_value.is_integer():
        build_value = int(build_value)

    try:
        if op(build_value, rule_value):
            PRE = "[INFO]"
            CHECK = "pass"
        elif rule.get("level") == "warning":
            # Warning-level rules never fail the build, but the prior
            # message ("[WARN] field pass test: a == b") was misleading
            # when a != b -- the build_value clearly differed from the
            # rule_value yet "pass" implied a match. Say "differs"
            # instead so the diagnostic reads naturally for fields like
            # the netlist hash where the user wants visibility without
            # an error.
            PRE = "[WARN]"
            CHECK = "differs"
            WARNS += 1
        else:
            PRE = "[ERROR]"
            CHECK = "fail"
            ERRORS += 1
    except TypeError:
        # Handle cases where types are not comparable (e.g., string vs. number)
        PRE = "[ERROR]"
        CHECK = "fail"
        ERRORS += 1
    print(PRE, field, CHECK, "test:", build_value, compare, rule_value)

print(f"Metadata check warnings: {WARNS}")

if ERRORS == 0:
    print(f"All metadata rules passed ({len(rules)} rules)")
else:
    print(f"Failed metadata checks: {ERRORS} out of {len(rules)}")

sys.exit(1 if ERRORS else 0)