from __future__ import annotations

import re

from src.rules import RULES
from src.schemas import ChangeSet, Finding
from src.domain import ReviewState, Severity

KEYWORD_RULES: list[tuple[str, str, re.Pattern[str]]] = [
    ("py-sql-concat", "sql-injection", re.compile(r"\.execute\s*\(")),
    ("py-cmd-shell", "command-injection", re.compile(r"os\.system|shell\s*=\s*True|os\.popen")),
    ("py-path-join", "path-traversal", re.compile(r"open\s*\(.*\+|send_file\s*\(")),
    ("py-pickle-load", "insecure-deserialization", re.compile(r"pickle\.loads|yaml\.load\s*\(")),
    ("py-ssrf-url", "ssrf", re.compile(r"urlopen\s*\(|requests\.(get|post)\s*\(")),
    ("py-xss-markup", "xss-template", re.compile(r"Markup\s*\(")),
    ("py-weak-password-hash", "weak-crypto", re.compile(r"hashlib\.md5|hashlib\.sha1")),
]


def keyword_findings(change: ChangeSet) -> list[Finding]:
    findings: list[Finding] = []
    index = 1
    for item in change.files:
        source = item.after if item.after.strip() else item.before
        for line_no, line in enumerate(source.splitlines(), start=1):
            for rule_id, family, pattern in KEYWORD_RULES:
                if not pattern.search(line):
                    continue
                spec = RULES[rule_id]
                findings.append(
                    Finding(
                        finding_id=f"K{index:03d}-{family}",
                        rule_id=rule_id,
                        family=family,
                        cwe=spec.cwe,
                        severity=spec.severity if isinstance(spec.severity, Severity) else Severity.MEDIUM,
                        path=item.path,
                        start_line=line_no,
                        end_line=line_no,
                        snippet=line.strip(),
                        review_state=ReviewState.HYPOTHETICAL,
                        method="keyword_only",
                        evidence_locator=f"{item.path}:{line_no}",
                        summary="Keyword baseline matched this line without AST or taint evidence.",
                        references=spec.references,
                        inference="Keyword match is not a confirmed weakness.",
                    )
                )
                index += 1
    return findings