"""Stage 7: Reviewer — Deterministic structural checks on generated skill."""
import re


def review_skill(generator_output, config):
    """
    Deterministic review of generated skill. No LLM involved.

    Checks that the SKILL.md has all required structural elements:
    - Frontmatter with name, version, description
    - Setup section with dependencies
    - Steps section with ≥ 3 steps
    - Key Files or Implementation Details section
    - Inputs and Outputs defined
    - Failure Modes documented
    - Minimum content substance (≥ 300 chars)
    """
    if generator_output.get("status") != "GENERATED":
        return {
            "status": "BLOCKED",
            "reason": "Generation failed",
        }

    files = generator_output.get("files", {})
    skill_md = files.get("SKILL.md", "")
    metadata = files.get("metadata.json", "{}")

    checks = {}
    issues = []

    # 1. Frontmatter exists with required fields
    has_frontmatter = skill_md.startswith("---") and "---" in skill_md[3:]
    has_name = "name:" in skill_md.split("---")[1] if has_frontmatter else False
    has_version = "version:" in skill_md
    has_description = "description:" in skill_md
    checks["frontmatter_complete"] = has_frontmatter and has_name and has_version and has_description

    # 2. Has Setup section with dependencies
    has_setup = "## Setup" in skill_md or "## Dependencies" in skill_md
    has_deps = "pip install" in skill_md or "requirements" in skill_md.lower() or "Dependencies" in skill_md
    checks["setup_documented"] = has_setup or has_deps

    # 3. Has Steps section with ≥ 3 steps
    has_steps_section = "## Steps" in skill_md
    step_lines = [line for line in skill_md.split("\n") if re.match(r"^\d+\.\s", line)]
    checks["has_steps"] = has_steps_section and len(step_lines) >= 3

    # 4. Has Key Files or Implementation Details section
    has_key_files = "## Key Files" in skill_md
    has_impl_details = "## Implementation Details" in skill_md
    checks["implementation_details"] = has_key_files or has_impl_details

    # 5. Inputs and Outputs defined
    has_inputs = "## Inputs" in skill_md
    has_outputs = "## Outputs" in skill_md
    checks["inputs_outputs_defined"] = has_inputs and has_outputs

    # 6. Failure Modes documented
    has_failure_modes = "## Failure Modes" in skill_md
    checks["failure_modes_documented"] = has_failure_modes

    # 7. Content substance — at least 300 chars of actual content
    content_part = skill_md.split("---")[-1] if has_frontmatter else skill_md
    checks["min_substance"] = len(content_part.strip()) >= 300

    # 8. Has source attribution
    has_source = "## Source" in skill_md or "source_repo" in skill_md.lower()
    checks["source_attribution"] = has_source

    # Score
    passed = sum(1 for v in checks.values() if v)
    total = len(checks)
    score = passed / total if total > 0 else 0

    min_score = config.get("reviewer", {}).get("min_score", 0.625)  # 5/8 checks
    decision = "PASS" if score >= min_score else "REJECT"

    # Build issue list
    for check_name, result in checks.items():
        if not result:
            issues.append(f"Missing: {check_name}")

    return {
        "status": "APPROVED" if decision == "PASS" else "REJECTED",
        "decision": decision,
        "score": round(score, 2),
        "min_score": min_score,
        "checks": checks,
        "issues": issues,
        "generator_output": generator_output,
    }