"""Unit tests for the opencode engine glue (no network, no opencode run)."""
import io
import os
import sys
import tarfile

HERE = os.path.dirname(os.path.abspath(__file__))
ROOT = os.path.abspath(os.path.join(HERE, "..", ".."))
sys.path.insert(0, os.path.join(ROOT, "pilot"))

import opencode_review as oc  # noqa: E402


# ---------------------------------------------------------------------------
# write_brief
# ---------------------------------------------------------------------------


def test_write_brief_contains_key_sections(tmp_path):
    brief = oc.write_brief(
        str(tmp_path),
        repo="masi/portfolio", index="3", sha="abcdef1234567890",
        title="Add eval helper", description="Closes #1",
        diff="diff --git a/x b/x\n+++ b/x\n@@ -1 +1,2 @@\n+eval(input())",
        config={"focus": ["security"], "instructions": "Flag eval()."},
        prior_reviews=["🤖 AI Review …\n- [high] old finding"],
    )
    assert brief.endswith(".pragent/brief.md")
    text = open(brief, encoding="utf-8").read()
    assert "masi/portfolio" in text
    assert "#3" in text
    assert "abcdef1234567890" in text
    assert "Add eval helper" in text
    assert "Closes #1" in text
    assert "eval(input())" in text
    assert "security" in text
    assert "Flag eval()" in text
    assert "old finding" in text
    assert "POST-CHANGE" in text  # anchor hint


def test_write_brief_none_config_and_prior(tmp_path):
    brief = oc.write_brief(
        str(tmp_path), repo="o/r", index="1", sha="sha1234567",
        title="t", description="", diff="d", config=None, prior_reviews=None,
    )
    text = open(brief, encoding="utf-8").read()
    assert "_(none)_" in text  # both config and prior fall back to none
    assert "diff" in text


# ---------------------------------------------------------------------------
# _extract_tar_strip_one — strips the single top-level dir
# ---------------------------------------------------------------------------


def _make_tar(top: str) -> bytes:
    """Build a tar.gz in memory with one top-level dir `top` containing files."""
    buf = io.BytesIO()
    with tarfile.open(fileobj=buf, mode="w:gz") as tar:
        # dir
        ti = tarfile.TarInfo(name=f"{top}/")
        ti.type = tarfile.DIRTYPE
        tar.addfile(ti)
        # file src/a.py
        data = b"print('a')\n"
        ti = tarfile.TarInfo(name=f"{top}/src/a.py")
        ti.size = len(data)
        tar.addfile(ti, io.BytesIO(data))
        # file README.md
        data = b"# hi\n"
        ti = tarfile.TarInfo(name=f"{top}/README.md")
        ti.size = len(data)
        tar.addfile(ti, io.BytesIO(data))
    return buf.getvalue()


def test_extract_tar_strips_top_level_dir(tmp_path):
    blob = _make_tar("repo-deadbeef")
    oc._extract_tar_strip_one(blob, str(tmp_path))
    # files sit directly at dest root (prefix stripped)
    assert os.path.isfile(tmp_path / "README.md")
    assert os.path.isfile(tmp_path / "src" / "a.py")
    assert not os.path.isdir(tmp_path / "repo-deadbeef")  # top dir gone


def test_extract_tar_no_common_prefix_extracts_as_is(tmp_path):
    # Two different top-level entries -> no strip.
    buf = io.BytesIO()
    with tarfile.open(fileobj=buf, mode="w:gz") as tar:
        for name, data in (("a.txt", b"A"), ("b.txt", b"B")):
            ti = tarfile.TarInfo(name=name)
            ti.size = len(data)
            tar.addfile(ti, io.BytesIO(data))
    oc._extract_tar_strip_one(buf.getvalue(), str(tmp_path))
    assert os.path.isfile(tmp_path / "a.txt")
    assert os.path.isfile(tmp_path / "b.txt")


def test_extract_tar_skips_parent_traversal(tmp_path):
    buf = io.BytesIO()
    with tarfile.open(fileobj=buf, mode="w:gz") as tar:
        ti = tarfile.TarInfo(name="top/../../escape.txt")
        data = b"evil"
        ti.size = len(data)
        tar.addfile(ti, io.BytesIO(data))
        ti = tarfile.TarInfo(name="top/ok.txt")
        data = b"ok"
        ti.size = len(data)
        tar.addfile(ti, io.BytesIO(data))
    oc._extract_tar_strip_one(buf.getvalue(), str(tmp_path))
    assert os.path.isfile(tmp_path / "ok.txt")
    assert not os.path.isfile(tmp_path / "escape.txt")
    assert not os.path.isfile(os.path.join(str(tmp_path), "..", "escape.txt"))


# ---------------------------------------------------------------------------
# drop_factory — copies opencode.json + .opencode/ from the repo
# ---------------------------------------------------------------------------


def test_drop_factory_copies_config_and_agents(tmp_path):
    oc.drop_factory(str(tmp_path))
    assert os.path.isfile(tmp_path / "opencode.json")
    assert os.path.isfile(tmp_path / ".opencode" / "agents" / "pragent.md")
    assert os.path.isfile(tmp_path / ".opencode" / "skills" / "findings-schema" / "SKILL.md")


# ---------------------------------------------------------------------------
# changed_files — extract changed paths from a unified diff
# ---------------------------------------------------------------------------


def test_changed_files_extracts_new_side_paths():
    diff = (
        "diff --git a/src/a.py b/src/a.py\n+++ b/src/a.py\n@@ -1 +1 @@\n-x\n+y\n"
        "diff --git a/README.md b/README.md\n+++ b/README.md\n@@ -1 +1 @@\n+z\n"
    )
    assert oc.changed_files(diff) == ["README.md", "src/a.py"]


def test_changed_files_skips_deletions_and_dedups():
    diff = (
        "diff --git a/gone.txt b/gone.txt\n+++ /dev/null\n@@ -1 +0,0 @@\n-old\n"
        "diff --git a/dup.go b/dup.go\n+++ b/dup.go\n@@ -1 +1 @@\n+a\n"
        "diff --git a/dup.go b/dup.go\n+++ b/dup.go\n@@ -1 +1 @@\n+b\n"
    )
    assert oc.changed_files(diff) == ["dup.go"]


def test_changed_files_empty():
    assert oc.changed_files("") == []
    assert oc.changed_files("no diff headers here") == []


def test_write_brief_lists_changed_files(tmp_path):
    brief = oc.write_brief(
        str(tmp_path), repo="o/r", index="1", sha="abcdef1234567890",
        title="t", description="d",
        diff="diff --git a/src/x.ts b/src/x.ts\n+++ b/src/x.ts\n@@ -1 +1 @@\n+x",
        config=None, prior_reviews=None,
    )
    text = open(brief, encoding="utf-8").read()
    assert "Changed files (focus your context research here)" in text
    assert "`src/x.ts`" in text


# ---------------------------------------------------------------------------
# parse_opencode_events — NDJSON → (text, usage)
# ---------------------------------------------------------------------------


def _ev(obj):
    import json
    return json.dumps(obj)


def test_parse_events_text_and_usage_summed():
    stdout = "\n".join([
        _ev({"type": "step_start", "part": {}}),
        _ev({"type": "text", "part": {"text": "Hello "}}),
        _ev({"type": "text", "part": {"text": "world"}}),
        _ev({"type": "step_finish", "part": {
            "tokens": {"total": 100, "input": 90, "output": 10,
                       "reasoning": 0, "cache": {"write": 0, "read": 5}},
            "cost": 0.0}}),
        _ev({"type": "text", "part": {"text": " more"}}),
        _ev({"type": "step_finish", "part": {
            "tokens": {"total": 50, "input": 40, "output": 10,
                       "reasoning": 2, "cache": {"write": 1, "read": 0}},
            "cost": 0.01}}),
    ])
    text, usage = oc.parse_opencode_events(stdout)
    assert text == "Hello world more"
    assert usage is not None
    assert usage["steps"] == 2
    assert usage["input"] == 130
    assert usage["output"] == 20
    assert usage["reasoning"] == 2
    assert usage["cache_read"] == 5
    assert usage["cache_write"] == 1
    assert usage["total"] == 150
    assert abs(usage["cost"] - 0.01) < 1e-9


def test_parse_events_no_step_finish_returns_none_usage():
    stdout = _ev({"type": "text", "part": {"text": "only text"}})
    text, usage = oc.parse_opencode_events(stdout)
    assert text == "only text"
    assert usage is None


def test_parse_events_tolerates_noise_and_malformed():
    stdout = "\n".join([
        "not json at all",
        _ev({"type": "text", "part": {"text": "ok"}}),
        "{ broken json",
        _ev({"type": "step_finish", "part": {}}),  # no tokens field -> counted, zero
        _ev({"type": "tool_start", "part": {"text": "ignored"}}),
        "  ",
    ])
    text, usage = oc.parse_opencode_events(stdout)
    assert text == "ok"
    # step_finish with no tokens still counts as a step; usage dict returned
    assert usage is not None
    assert usage["steps"] == 1
    assert usage["input"] == 0 and usage["output"] == 0