#!/usr/bin/env bash
# genchi-genbutsu.sh — 現地現物 — Go and see. Verify world state, not log vibes.
#
# Post-completion verification that goes and LOOKS at the actual artifacts.
# Performs 5 world-state checks:
#   1. Branch exists on remote
#   2. PR exists
#   3. PR has real file changes (> 0)
#   4. PR is mergeable
#   5. Issue has a completion comment from the agent
#
# Usage: genchi-genbutsu.sh <repo_owner> <repo_name> <issue_num> <branch> <agent_name>
# Returns: JSON to stdout, logs JSONL, exit 0 = VERIFIED, exit 1 = UNVERIFIED

set -euo pipefail

GITEA_URL="${GITEA_URL:-https://forge.alexanderwhitestone.com}"
GITEA_TOKEN="${GITEA_TOKEN:-}"
LOG_DIR="${LOG_DIR:-$HOME/.hermes/logs}"
VERIFY_LOG="$LOG_DIR/genchi-genbutsu.jsonl"

if [ $# -lt 5 ]; then
  echo "Usage: $0 <repo_owner> <repo_name> <issue_num> <branch> <agent_name>" >&2
  exit 2
fi

repo_owner="$1"
repo_name="$2"
issue_num="$3"
branch="$4"
agent_name="$5"

mkdir -p "$LOG_DIR"

# ── Helpers ──────────────────────────────────────────────────────────

check_branch_exists() {
  # Use Gitea API instead of git ls-remote so we don't need clone credentials
  curl -sf "${GITEA_URL}/api/v1/repos/${repo_owner}/${repo_name}/branches/${branch}" \
    -H "Authorization: token ${GITEA_TOKEN}" >/dev/null 2>&1
}

get_pr_num() {
  curl -sf "${GITEA_URL}/api/v1/repos/${repo_owner}/${repo_name}/pulls?state=all&head=${repo_owner}:${branch}&limit=1" \
    -H "Authorization: token ${GITEA_TOKEN}" 2>/dev/null | python3 -c "
import sys, json
prs = json.load(sys.stdin)
print(prs[0]['number'] if prs else '')
"
}

check_pr_files() {
  local pr_num="$1"
  curl -sf "${GITEA_URL}/api/v1/repos/${repo_owner}/${repo_name}/pulls/${pr_num}/files" \
    -H "Authorization: token ${GITEA_TOKEN}" 2>/dev/null | python3 -c "
import sys, json
try:
    files = json.load(sys.stdin)
    print(len(files) if isinstance(files, list) else 0)
except:
    print(0)
"
}

check_pr_mergeable() {
  local pr_num="$1"
  curl -sf "${GITEA_URL}/api/v1/repos/${repo_owner}/${repo_name}/pulls/${pr_num}" \
    -H "Authorization: token ${GITEA_TOKEN}" 2>/dev/null | python3 -c "
import sys, json
pr = json.load(sys.stdin)
print('true' if pr.get('mergeable') else 'false')
"
}

check_completion_comment() {
  curl -sf "${GITEA_URL}/api/v1/repos/${repo_owner}/${repo_name}/issues/${issue_num}/comments" \
    -H "Authorization: token ${GITEA_TOKEN}" 2>/dev/null | AGENT="$agent_name" python3 -c "
import os, sys, json
agent = os.environ.get('AGENT', '').lower()
try:
    comments = json.load(sys.stdin)
except:
    sys.exit(1)
for c in reversed(comments):
    user = ((c.get('user') or {}).get('login') or '').lower()
    if user == agent:
        sys.exit(0)
sys.exit(1)
"
}

# ── Run checks ───────────────────────────────────────────────────────

ts=$(date -u '+%Y-%m-%dT%H:%M:%SZ')
status="VERIFIED"
details=()
checks_json='{}'

# Check 1: branch
if check_branch_exists; then
  checks_json=$(echo "$checks_json" | python3 -c "import sys,json;d=json.load(sys.stdin);d['branch']=True;print(json.dumps(d))")
else
  checks_json=$(echo "$checks_json" | python3 -c "import sys,json;d=json.load(sys.stdin);d['branch']=False;print(json.dumps(d))")
  status="UNVERIFIED"
  details+=("remote branch ${branch} not found")
fi

# Check 2: PR exists
pr_num=$(get_pr_num)
if [ -n "$pr_num" ]; then
  checks_json=$(echo "$checks_json" | python3 -c "import sys,json;d=json.load(sys.stdin);d['pr']=True;print(json.dumps(d))")
else
  checks_json=$(echo "$checks_json" | python3 -c "import sys,json;d=json.load(sys.stdin);d['pr']=False;print(json.dumps(d))")
  status="UNVERIFIED"
  details+=("no PR found for branch ${branch}")
fi

# Check 3: PR has real file changes
if [ -n "$pr_num" ]; then
  file_count=$(check_pr_files "$pr_num")
  if [ "${file_count:-0}" -gt 0 ]; then
    checks_json=$(echo "$checks_json" | python3 -c "import sys,json;d=json.load(sys.stdin);d['files']=True;print(json.dumps(d))")
  else
    checks_json=$(echo "$checks_json" | python3 -c "import sys,json;d=json.load(sys.stdin);d['files']=False;print(json.dumps(d))")
    status="UNVERIFIED"
    details+=("PR #${pr_num} has 0 changed files")
  fi

  # Check 4: PR is mergeable
  if [ "$(check_pr_mergeable "$pr_num")" = "true" ]; then
    checks_json=$(echo "$checks_json" | python3 -c "import sys,json;d=json.load(sys.stdin);d['mergeable']=True;print(json.dumps(d))")
  else
    checks_json=$(echo "$checks_json" | python3 -c "import sys,json;d=json.load(sys.stdin);d['mergeable']=False;print(json.dumps(d))")
    status="UNVERIFIED"
    details+=("PR #${pr_num} is not mergeable")
  fi
else
  checks_json=$(echo "$checks_json" | python3 -c "import sys,json;d=json.load(sys.stdin);d['files']=None;d['mergeable']=None;print(json.dumps(d))")
fi

# Check 5: completion comment from agent
if check_completion_comment; then
  checks_json=$(echo "$checks_json" | python3 -c "import sys,json;d=json.load(sys.stdin);d['comment']=True;print(json.dumps(d))")
else
  checks_json=$(echo "$checks_json" | python3 -c "import sys,json;d=json.load(sys.stdin);d['comment']=False;print(json.dumps(d))")
  status="UNVERIFIED"
  details+=("no completion comment from ${agent_name} on issue #${issue_num}")
fi

# Build detail string
detail_str=$(IFS="; "; echo "${details[*]:-all checks passed}")

# ── Output ───────────────────────────────────────────────────────────

result=$(python3 -c "
import json
print(json.dumps({
    'status': '$status',
    'repo': '${repo_owner}/${repo_name}',
    'issue': $issue_num,
    'branch': '$branch',
    'agent': '$agent_name',
    'pr': '$pr_num',
    'checks': $checks_json,
    'details': '$detail_str',
    'ts': '$ts'
}, indent=2))
")

printf '%s\n' "$result"

# Append to JSONL log
printf '%s\n' "$result" >> "$VERIFY_LOG"

if [ "$status" = "VERIFIED" ]; then
  exit 0
else
  exit 1
fi