#!/usr/bin/env bash
set -euo pipefail

usage() {
  cat <<EOF
Usage: validate-provenance.sh <agent-file>

Validate that an agent pair's sources provenance chain is complete and internally consistent.
Operates at plugin scope only — exits 0 silently for project and user scope agents.

Arguments:
  agent-file  Path to either the Claude Code .md or Copilot .agent.md agent file.

Exit codes:
  0  All checks passed (or nothing to validate, or not plugin scope)
  1  One or more checks failed

Checks performed:
  0  source_keys present in agent pair but agents/sources.md absent
  1  FILL IN: placeholders in agents/sources.md
  2  source_keys in agent files → slug exists in agents/sources.md
  3  Contributing files listed in agents/sources.md exist on disk (plugin-root relative)
  4  Contributing files back-reference the parent slug in their source_keys
  5  Research doc field present and not placeholder
EOF
}

if [[ "${1:-}" == "--help" || "${1:-}" == "-h" ]]; then
  usage
  exit 0
fi

if [[ $# -lt 1 ]]; then
  echo "Error: agent-file is required." >&2
  echo "" >&2
  usage >&2
  exit 1
fi

python3 -u - "$1" <<'PYTHON'
import sys
import os
import re

agent_file = os.path.abspath(sys.argv[1])
fname = os.path.basename(agent_file)
agent_dir = os.path.dirname(agent_file)

# --- Detect provider ---
if fname.endswith('.agent.md'):
    provider = 'copilot'
    name_stem = fname[:-len('.agent.md')]
elif fname.endswith('.md'):
    provider = 'claude-code'
    name_stem = fname[:-len('.md')]
else:
    print(f"Error: unrecognized extension '{fname}' — expected .md or .agent.md", file=sys.stderr)
    sys.exit(2)

# --- Find plugin root ---
def find_plugin_root(start_dir):
    current = os.path.abspath(start_dir)
    while True:
        if (os.path.isfile(os.path.join(current, 'plugin.json')) or os.path.isfile(os.path.join(current, '.claude-plugin', 'plugin.json'))):
            return current
        parent = os.path.dirname(current)
        if parent == current:
            return None
        current = parent

plugin_root = find_plugin_root(agent_dir)
if plugin_root is None:
    sys.exit(0)

# --- Derive counterpart ---
if provider == 'copilot':
    counterpart = os.path.join(agent_dir, name_stem + '.md')
else:
    counterpart = os.path.join(agent_dir, name_stem + '.agent.md')

sources_md_path = os.path.join(plugin_root, 'agents', 'sources.md')

# --- Helpers ---
PLACEHOLDER_RE = re.compile(r'(?<!`)FILL IN:[^`\n]')

def parse_frontmatter(content):
    m = re.match(r'^---\n(.*?)\n---', content, re.DOTALL)
    if not m:
        return None, content
    return m.group(1), content[m.end():]

def parse_source_keys(fm):
    """Extract top-level source_keys list from frontmatter string."""
    if fm is None:
        return []
    keys = []
    in_source_keys = False
    for line in fm.splitlines():
        if re.match(r'^source_keys:', line):
            in_source_keys = True
            continue
        if in_source_keys:
            m = re.match(r'^[ \t]+-\s+(\S+)', line)
            if m:
                keys.append(m.group(1).strip())
            elif line and not line[0].isspace():
                in_source_keys = False
    return keys

def parse_h2_slugs(content):
    return re.findall(r'^## (.+)$', content, re.MULTILINE)

def parse_contributing_files(content, slug):
    pattern = re.compile(
        r'^## ' + re.escape(slug) + r'\s*\n(.*?)(?=^## |\Z)',
        re.MULTILINE | re.DOTALL
    )
    m = pattern.search(content)
    if not m:
        return None
    block = m.group(1)
    cf_m = re.search(r'^\- \*\*Contributing files:\*\* (.+)$', block, re.MULTILINE)
    if not cf_m:
        return None
    return cf_m.group(1).strip()

def parse_research_doc(content, slug):
    pattern = re.compile(
        r'^## ' + re.escape(slug) + r'\s*\n(.*?)(?=^## |\Z)',
        re.MULTILINE | re.DOTALL
    )
    m = pattern.search(content)
    if not m:
        return None
    block = m.group(1)
    rd_m = re.search(r'^\- \*\*Research doc:\*\* (.+)$', block, re.MULTILINE)
    if not rd_m:
        return None
    return rd_m.group(1).strip()

findings = []
has_fail = False

def emit_fail(desc, fpath, why, fix):
    global has_fail
    has_fail = True
    findings.append(("FAIL", desc, fpath, why, fix))

def print_findings():
    for kind, desc, fpath, why, fix in findings:
        print(f"FAIL  {desc} — {fpath}")
        print(f"      Why: {why}")
        print(f"      Fix: {fix}")
        print()

# --- Collect source_keys from agent pair ---
def get_source_keys_from_file(fpath):
    if not os.path.isfile(fpath):
        return []
    try:
        with open(fpath) as f:
            content = f.read()
    except Exception:
        return []
    fm, _ = parse_frontmatter(content)
    return parse_source_keys(fm)

given_keys = get_source_keys_from_file(agent_file)
counterpart_keys = get_source_keys_from_file(counterpart)
# Deduplicated union, preserving order
seen = set()
all_source_keys = []
for k in given_keys + counterpart_keys:
    if k not in seen:
        seen.add(k)
        all_source_keys.append(k)

sources_md_exists = os.path.isfile(sources_md_path)

# Early exit: nothing to validate
if not all_source_keys and not sources_md_exists:
    sys.exit(0)

sources_content = None
sources_slugs = set()
if sources_md_exists:
    with open(sources_md_path) as f:
        sources_content = f.read()
    sources_slugs = set(parse_h2_slugs(sources_content))

# --- Check 0: source_keys present but agents/sources.md absent ---
if not sources_md_exists and all_source_keys:
    rel_given = os.path.relpath(agent_file, plugin_root)
    emit_fail(
        "source_keys declared but agents/sources.md is absent",
        rel_given,
        "source_keys references research provenance that has no sources index to validate against.",
        "Create agents/sources.md with an H2 entry for each slug referenced by source_keys."
    )
    print_findings()
    sys.exit(1)

# --- Check 1: FILL IN: placeholders in agents/sources.md ---
for line in sources_content.splitlines():
    if PLACEHOLDER_RE.search(line):
        emit_fail(
            "Unfilled FILL IN: placeholder",
            "agents/sources.md",
            "agents/sources.md contains an unfilled placeholder, meaning provenance is incomplete.",
            "Replace all 'FILL IN:' values in agents/sources.md with real content."
        )
        break

# --- Check 2: source_keys in agent files → slug exists in agents/sources.md ---
for fpath, keys in [(agent_file, given_keys), (counterpart, counterpart_keys)]:
    if not keys:
        continue
    rel = os.path.relpath(fpath, plugin_root)
    for slug in keys:
        if slug not in sources_slugs:
            emit_fail(
                f"source_keys slug '{slug}' not found in agents/sources.md",
                rel,
                f"'{rel}' declares '{slug}' as a source but there is no '## {slug}' heading in agents/sources.md.",
                f"Add '## {slug}' entry to agents/sources.md or remove '{slug}' from {rel} source_keys."
            )

# --- Checks 3, 4, 5: Per-slug checks in agents/sources.md ---
for slug in parse_h2_slugs(sources_content):
    # Check 3: Contributing files exist (paths relative to plugin root)
    cf_value = parse_contributing_files(sources_content, slug)
    if cf_value and not cf_value.startswith("(none"):
        cf_files = [p.strip() for p in cf_value.split(",") if p.strip()]
        for cf_rel in cf_files:
            cf_abs = os.path.join(plugin_root, cf_rel)
            if not os.path.isfile(cf_abs):
                emit_fail(
                    f"Contributing file '{cf_rel}' does not exist",
                    f"agents/sources.md (## {slug})",
                    f"agents/sources.md claims '{cf_rel}' was contributed to by slug '{slug}' but the file does not exist.",
                    f"Create '{cf_rel}' relative to the plugin root, or correct the path in agents/sources.md."
                )
            else:
                # Check 4: Bidirectional — file should list slug in its source_keys
                with open(cf_abs) as f:
                    cf_content = f.read()
                cf_fm, _ = parse_frontmatter(cf_content)
                cf_keys = parse_source_keys(cf_fm)
                if slug not in cf_keys:
                    emit_fail(
                        f"Contributing file '{cf_rel}' does not list '{slug}' in its source_keys",
                        f"agents/sources.md (## {slug})",
                        f"agents/sources.md says '{cf_rel}' was informed by '{slug}', but '{cf_rel}' does not declare '{slug}' in its top-level source_keys.",
                        f"Add '{slug}' to the top-level source_keys frontmatter in '{cf_rel}'."
                    )

    # Check 5: Research doc field required
    rd_value = parse_research_doc(sources_content, slug)
    if rd_value is None:
        emit_fail(
            "Research doc field missing",
            f"agents/sources.md (## {slug})",
            f"The '## {slug}' entry in agents/sources.md has no '- **Research doc:**' line.",
            f"Add '- **Research doc:** <path-or-(none)>' to the '## {slug}' entry in agents/sources.md."
        )
    elif rd_value == "" or PLACEHOLDER_RE.search(rd_value):
        emit_fail(
            "Research doc field is empty or placeholder",
            f"agents/sources.md (## {slug})",
            f"The '## {slug}' entry has an unfilled Research doc value.",
            "Set '- **Research doc:**' to a real path relative to repo root, or '(none)' if not applicable."
        )

print_findings()
sys.exit(1 if has_fail else 0)
PYTHON