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

ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
cd "$ROOT"

ts="$(date -u +"%Y-%m-%dT%H:%M:%SZ")"

mkdir -p out

git_branch=""
git_head=""
git_head_short=""
git_modified_count="0"
git_untracked_count="0"
git_dirty_count="0"

if git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
  git_branch="$(git rev-parse --abbrev-ref HEAD 2>/dev/null || echo "?")"
  git_head="$(git rev-parse HEAD 2>/dev/null || echo "")"
  git_head_short="$(git rev-parse --short HEAD 2>/dev/null || echo "")"
  porcelain="$(git status --porcelain=v1 2>/dev/null || true)"
  if [ -n "${porcelain}" ]; then
    git_dirty_count="$(printf "%s\n" "${porcelain}" | wc -l | awk '{print $1}')"
    git_untracked_count="$(printf "%s\n" "${porcelain}" | grep -c '^??' || true)"
    git_modified_count="$(printf "%s\n" "${porcelain}" | grep -vc '^??' || true)"
  fi
fi

latest_checkpoint_path=""
latest_checkpoint_sha256=""
if ls out/checkpoints/iftypeset_checkpoint_*.tar.gz >/dev/null 2>&1; then
  latest_checkpoint_path="$(ls -1t out/checkpoints/iftypeset_checkpoint_*.tar.gz | head -n 1)"
  latest_checkpoint_sha256="$(sha256sum "${latest_checkpoint_path}" | awk '{print $1}')"
fi

export IFTS_STATE_TS="${ts}"
export IFTS_STATE_ROOT="${ROOT}"
export IFTS_STATE_GIT_BRANCH="${git_branch}"
export IFTS_STATE_GIT_HEAD="${git_head}"
export IFTS_STATE_GIT_HEAD_SHORT="${git_head_short}"
export IFTS_STATE_GIT_DIRTY_COUNT="${git_dirty_count}"
export IFTS_STATE_GIT_MODIFIED_COUNT="${git_modified_count}"
export IFTS_STATE_GIT_UNTRACKED_COUNT="${git_untracked_count}"
export IFTS_STATE_CHECKPOINT_PATH="${latest_checkpoint_path}"
export IFTS_STATE_CHECKPOINT_SHA256="${latest_checkpoint_sha256}"

python3 - <<'PY'
import json
import os
from pathlib import Path


def _read_json(path: str):
    p = Path(path)
    if not p.exists():
        return None
    try:
        return json.loads(p.read_text())
    except Exception:
        return None


ts = os.environ.get("IFTS_STATE_TS", "")
root = os.environ.get("IFTS_STATE_ROOT", "")
git_branch = os.environ.get("IFTS_STATE_GIT_BRANCH", "")
git_head = os.environ.get("IFTS_STATE_GIT_HEAD", "")
git_head_short = os.environ.get("IFTS_STATE_GIT_HEAD_SHORT", "")
dirty_count = int(os.environ.get("IFTS_STATE_GIT_DIRTY_COUNT", "0") or "0")
modified_count = int(os.environ.get("IFTS_STATE_GIT_MODIFIED_COUNT", "0") or "0")
untracked_count = int(os.environ.get("IFTS_STATE_GIT_UNTRACKED_COUNT", "0") or "0")
checkpoint_path = os.environ.get("IFTS_STATE_CHECKPOINT_PATH", "")
checkpoint_sha256 = os.environ.get("IFTS_STATE_CHECKPOINT_SHA256", "")

coverage = _read_json("out/coverage-report.json") or {}
counts = coverage.get("counts", {}) if isinstance(coverage, dict) else {}

trust_contract_md = Path("out/trust-contract.md").exists()
trust_contract_json = Path("out/trust-contract.json").exists()

state = {
    "generated_at_utc": ts,
    "repo_root": root,
    "git": {
        "branch": git_branch or None,
        "head": git_head or None,
        "head_short": git_head_short or None,
        "dirty_paths_count": dirty_count,
        "modified_paths_count": modified_count,
        "untracked_paths_count": untracked_count,
    },
    "latest_checkpoint": {
        "path": checkpoint_path or None,
        "sha256": checkpoint_sha256 or None,
    },
    "coverage": {
        "generated_at_utc": coverage.get("generated_at_utc") if isinstance(coverage, dict) else None,
        "counts": counts or None,
    },
    "artifacts": {
        "trust_contract_md": trust_contract_md,
        "trust_contract_json": trust_contract_json,
        "coverage_report_json": Path("out/coverage-report.json").exists(),
        "manual_checklist_md": Path("out/manual-checklist.md").exists(),
    },
    "canonical_docs": [
        "README.md",
        "STATUS.md",
        "docs/06-project-overview.md",
        "docs/07-session-resilience.md",
        "docs/09-project-status.md",
        "docs/10-project-brief.md",
        "docs/12-codex-max-workload.md",
        "docs/13-task-board.md",
        "docs/17-rendering-pipeline.md",
        "docs/CHECKPOINTS.md",
    ],
    "resume_commands": [
        "./scripts/resume.sh",
        "./scripts/audit.sh",
        "./scripts/state.sh",
        "./scripts/ci.sh",
        "./scripts/checkpoint.sh \"note\"",
    ],
}

Path("out/session-state.json").write_text(json.dumps(state, indent=2, sort_keys=True) + "\n")

lines = []
lines.append("# Session State (generated)\n")
lines.append(f"- generated_at_utc: `{ts}`")
lines.append(f"- repo_root: `{root}`")
if git_branch and git_head_short:
    lines.append(f"- git: `{git_branch}` @ `{git_head_short}`")
elif git_branch:
    lines.append(f"- git: `{git_branch}`")
else:
    lines.append("- git: `(not detected)`")
lines.append(
    f"- working_tree: dirty_paths={dirty_count} (modified={modified_count}, untracked={untracked_count})"
)
if checkpoint_path:
    lines.append(f"- latest_checkpoint: `{checkpoint_path}`")
    lines.append(f"- latest_checkpoint_sha256: `{checkpoint_sha256}`")
else:
    lines.append("- latest_checkpoint: `(none yet)`")

total_rules = None
try:
    total_rules = counts.get("total_rules")
except Exception:
    total_rules = None
if total_rules is not None:
    lines.append(f"- rules_total: `{total_rules}`")
    by_enf = counts.get("by_enforcement") or {}
    by_cat = counts.get("by_category") or {}
    if by_enf:
        lines.append(f"- enforcement_split: `{by_enf}`")
    if by_cat:
        lines.append(f"- categories: `{by_cat}`")
else:
    lines.append("- rules_total: `(unknown; run ./scripts/ci.sh)`")

lines.append("")
lines.append("## Canonical Docs")
for d in state["canonical_docs"]:
    lines.append(f"- `{d}`")

lines.append("")
lines.append("## Fast Resume")
for c in state["resume_commands"]:
    lines.append(f"- `{c}`")

lines.append("")
lines.append("## Notes")
lines.append(
    "- If a chat/session resets and things look “rolled back”, check `latest_checkpoint` above and extract it on a new machine."
)
lines.append(
    "- This file is copied into `docs/SESSION_STATE.md` so it is included in checkpoint snapshots (since `out/` is excluded)."
)

md = "\n".join(lines) + "\n"
Path("out/session-state.md").write_text(md)
Path("docs/SESSION_STATE.md").write_text(md)
PY

echo "wrote: out/session-state.json out/session-state.md docs/SESSION_STATE.md" >&2