"""E2E vertical slice: observe → index → command → git evidence → rebuild."""

from __future__ import annotations

import json
import subprocess
from pathlib import Path

from repo_manager.commands.task_status import update_task_status
from repo_manager.gitops import head_sha
from repo_manager.index_store import default_index_path, load_index
from repo_manager.observe import observe_repository


WORKPLAN = """---
id: DEMO-WP-0001
type: workplan
title: "Demo workplan"
status: active
---

# Demo workplan

## First task

```task
id: DEMO-WP-0001-T01
status: todo
priority: high
```

Do the thing.
"""


def _git(repo: Path, *args: str) -> None:
    subprocess.run(["git", *args], cwd=repo, check=True, capture_output=True)


def _init_fixture(tmp_path: Path) -> Path:
    repo = tmp_path / "demo-repo"
    repo.mkdir()
    _git(repo, "init")
    _git(repo, "config", "user.email", "test@example.com")
    _git(repo, "config", "user.name", "Test")
    (repo / "workplans").mkdir()
    (repo / "workplans" / "DEMO-WP-0001-demo.md").write_text(WORKPLAN, encoding="utf-8")
    (repo / ".repo-classification.yaml").write_text(
        "repo_classification:\n  category: experimental\n  domain: infotech\n",
        encoding="utf-8",
    )
    (repo / "INTENT.md").write_text("# INTENT\n\nDemo fixture repository.\n", encoding="utf-8")
    _git(repo, "add", ".")
    _git(repo, "commit", "-m", "seed")
    return repo


def test_e2e_vertical_slice(tmp_path: Path):
    repo = _init_fixture(tmp_path)
    before = head_sha(repo)
    assert before

    # 1–2. Observe + index declared work
    snap, index = observe_repository(repo, slug="demo-repo")
    assert snap["slug"] == "demo-repo"
    assert snap["classification"]["category"] == "experimental"
    assert snap["index"]["workplan_count"] == 1
    assert snap["index"]["task_count"] == 1
    tasks = [r for r in index.work_records if r.kind == "task"]
    assert tasks[0].id == "DEMO-WP-0001-T01"
    assert tasks[0].status == "todo"

    # 3–4. Apply governed file-backed transition + git evidence
    result = update_task_status(
        repo,
        "DEMO-WP-0001-T01",
        "progress",
        correlation_id="00000000-0000-4000-8000-000000000001",
        reason="e2e proof",
    )
    assert result.status == "applied", result
    assert result.evidence.get("git_sha")
    assert result.evidence["git_sha"] != before
    assert result.evidence["files_touched"] == ["workplans/DEMO-WP-0001-demo.md"]

    # File content updated
    text = (repo / "workplans" / "DEMO-WP-0001-demo.md").read_text(encoding="utf-8")
    assert "status: progress" in text

    # 5. Rebuilt projection
    snap2, index2 = observe_repository(repo, slug="demo-repo")
    task2 = next(r for r in index2.work_records if r.id == "DEMO-WP-0001-T01")
    assert task2.status == "progress"
    assert snap2["revision"]["head_sha"] == result.evidence["git_sha"]

    # Index on disk includes command event (normalized change)
    idx_path = default_index_path(repo)
    assert idx_path.is_file()
    stored = load_index(idx_path)
    types = [e.get("type") for e in stored.events]
    assert "repo.command.applied" in types
    applied = next(e for e in stored.events if e.get("type") == "repo.command.applied")
    assert applied["correlation_id"] == "00000000-0000-4000-8000-000000000001"
    assert applied["git_sha"] == result.evidence["git_sha"]

    # Proof artifact for humans
    proof = {
        "slice": "RMGR-WP-0001-T05",
        "repo_slug": "demo-repo",
        "before_sha": before,
        "after_sha": result.evidence["git_sha"],
        "command": result.to_dict(),
        "snapshot_after": snap2,
    }
    proof_path = tmp_path / "e2e-proof.json"
    proof_path.write_text(json.dumps(proof, indent=2), encoding="utf-8")
    assert proof_path.stat().st_size > 0