"""Unit tests for agent_team.dispatcher — the trusted apply-path transport (§4.3).

Fully hermetic: the branch-push and workflow-dispatch side effects are injected
fakes, so no git, no ``gh``, and no network are exercised. The tests pin the
pure input-assembly + validation contract and the push-before-dispatch order.
"""

from __future__ import annotations

import base64

import pytest

from agent_team.dispatcher import (
    MAX_DIFF_BYTES,
    DispatcherError,
    DispatchInputs,
    build_dispatch_inputs,
    dispatch_apply_verify,
    head_branch_for,
)
from agent_team.state_store import compute_content_hash

TASK = "0a1b2c3d4e5f6071"
DIFF = "diff --git a/README.md b/README.md\n--- a/README.md\n+++ b/README.md\n@@ -1 +1,2 @@\n title\n+added line\n"
SCOPE = "README.md\ndocs/**"


# --------------------------------------------------------------------------- #
# build_dispatch_inputs (pure)
# --------------------------------------------------------------------------- #


def test_build_dispatch_inputs_binds_hash_and_b64() -> None:
    di = build_dispatch_inputs(task_id=TASK, diff_text=DIFF, declared_scope=SCOPE)
    # expected_diff_hash is the plain sha256 the workflow's sha256sum reproduces.
    assert di.expected_diff_hash == compute_content_hash(DIFF.encode("utf-8"))
    # diff_b64 round-trips back to the exact diff bytes.
    assert base64.b64decode(di.diff_b64).decode("utf-8") == DIFF
    assert di.head_branch == f"agent-team/apply/{TASK}"
    assert di.diff_artifact_name == f"agent-team-diff-{TASK}"
    assert di.declared_scope == SCOPE


def test_as_inputs_keys_match_the_six_workflow_inputs() -> None:
    di = build_dispatch_inputs(task_id=TASK, diff_text=DIFF, declared_scope=SCOPE)
    assert set(di.as_inputs()) == {
        "task_id",
        "diff_artifact_name",
        "expected_diff_hash",
        "declared_scope",
        "diff_b64",
        "head_branch",
    }


@pytest.mark.parametrize("bad_diff", ["", "   ", "\n\n"])
def test_empty_diff_rejected(bad_diff: str) -> None:
    with pytest.raises(DispatcherError):
        build_dispatch_inputs(task_id=TASK, diff_text=bad_diff, declared_scope=SCOPE)


def test_oversized_diff_rejected() -> None:
    # The diff rides a base64 workflow_dispatch input (GitHub ~64 KB cap); a diff
    # over MAX_DIFF_BYTES must fail closed in the dispatcher, not be dispatched.
    big = "diff --git a/x b/x\n" + "+" + ("x" * (MAX_DIFF_BYTES + 1)) + "\n"
    with pytest.raises(DispatcherError):
        build_dispatch_inputs(task_id=TASK, diff_text=big, declared_scope=SCOPE)


@pytest.mark.parametrize("bad_scope", ["", "   "])
def test_empty_scope_rejected(bad_scope: str) -> None:
    # An empty declared scope would let a diff touch ANY path — fail closed.
    with pytest.raises(DispatcherError):
        build_dispatch_inputs(task_id=TASK, diff_text=DIFF, declared_scope=bad_scope)


@pytest.mark.parametrize(
    "bad_task", ["", "has space", "semi;colon", "../escape", "a/b", "x" * 201]
)
def test_unsafe_task_id_rejected(bad_task: str) -> None:
    with pytest.raises(DispatcherError):
        head_branch_for(bad_task)
    with pytest.raises(DispatcherError):
        build_dispatch_inputs(task_id=bad_task, diff_text=DIFF, declared_scope=SCOPE)


# --------------------------------------------------------------------------- #
# dispatch_apply_verify (injected seams)
# --------------------------------------------------------------------------- #


class _Recorder:
    def __init__(self) -> None:
        self.calls: list[dict] = []


def test_dispatch_pushes_then_fires_with_correct_inputs() -> None:
    order: list[str] = []
    pushed = _Recorder()
    fired = _Recorder()

    def pusher(*, owner, repo, base, head_branch, diff_text):
        order.append("push")
        pushed.calls.append(
            {
                "owner": owner,
                "repo": repo,
                "base": base,
                "head": head_branch,
                "diff": diff_text,
            }
        )

    def dispatcher(*, owner, repo, inputs, ref):
        order.append("dispatch")
        fired.calls.append({"owner": owner, "repo": repo, "inputs": inputs, "ref": ref})

    di = dispatch_apply_verify(
        owner="Sea-Haven-Industries",
        repo="orchestrator",
        task_id=TASK,
        diff_text=DIFF,
        declared_scope=SCOPE,
        pusher=pusher,
        dispatcher=dispatcher,
    )

    assert isinstance(di, DispatchInputs)
    # Branch is pushed BEFORE the workflow is dispatched (the draft-PR step opens
    # against an already-pushed --head).
    assert order == ["push", "dispatch"]
    assert pushed.calls[0]["head"] == f"agent-team/apply/{TASK}"
    assert pushed.calls[0]["diff"] == DIFF
    # The dispatch carries all six inputs, including the b64 diff + head branch.
    inputs = fired.calls[0]["inputs"]
    assert inputs["head_branch"] == f"agent-team/apply/{TASK}"
    assert base64.b64decode(inputs["diff_b64"]).decode("utf-8") == DIFF
    assert inputs["expected_diff_hash"] == compute_content_hash(DIFF.encode("utf-8"))
    assert fired.calls[0]["ref"] == "main"


def test_dispatch_does_not_fire_if_push_fails() -> None:
    fired = _Recorder()

    def failing_pusher(**_kw):
        raise RuntimeError("push failed")

    def dispatcher(**kw):
        fired.calls.append(kw)

    with pytest.raises(RuntimeError):
        dispatch_apply_verify(
            owner="o",
            repo="r",
            task_id=TASK,
            diff_text=DIFF,
            declared_scope=SCOPE,
            pusher=failing_pusher,
            dispatcher=dispatcher,
        )
    # A failed push must NOT dispatch a run (no orphan run against a missing head).
    assert fired.calls == []


@pytest.mark.parametrize(
    "owner,repo", [("", "r"), ("o", ""), ("bad owner", "r"), ("o", "r/x")]
)
def test_unsafe_owner_repo_rejected(owner: str, repo: str) -> None:
    with pytest.raises(DispatcherError):
        dispatch_apply_verify(
            owner=owner,
            repo=repo,
            task_id=TASK,
            diff_text=DIFF,
            declared_scope=SCOPE,
            pusher=lambda **_k: None,
            dispatcher=lambda **_k: None,
        )