"""A work item's place in the loop (L1), kept in its row in the state store.

The row's ``position`` is the item's state; what the loop needs besides
(the thread its conversation lives in, the revision of what is put up for
agreement, what it is waiting for) is in ``data["loop"]``.
"""

from dataclasses import asdict, dataclass
from typing import Any

from nisse_dev.state import StateStore, WorkItem

READY = "ready"
RUNNING = "running"  # a driver run is under way; on boot it means interrupted
WAITING = "waiting"
CLOSED = "closed"

# What a waiting item waits for.
GO_AHEAD = "go-ahead"  # a go on the restatement up (L3, D1)
ANSWER = "answer"  # an answer to a question
MERGE = "merge"  # the PR's review and merge (D4, D5)


@dataclass(frozen=True)
class Loop:
    thread: str = ""  # the root of the item's Matrix thread (L5)
    issue: int = 0  # its record issue (D1)
    wait: str = ""  # GO_AHEAD / ANSWER, when waiting
    rev: int = 0  # the latest proposal put up (L3)
    started: bool = False  # scope agreed: a go-ahead was given (D1)
    note: str = ""  # what a waiting item said it is waiting on
    prepared: bool = False  # its fresh workspace was made (D3)
    milestone: int = 0  # the current milestone (D4)
    branch: str = ""  # the current milestone's branch, while one is open
    pr: int = 0  # the current milestone's PR, once published
    pr_url: str = ""
    comments: int = 0  # the last PR conversation comment taken (L8)
    notes: tuple[str, ...] = ()  # review notes taken (#69)
    fixes: int = 0  # review fixes pushed, for follow-up branch names

    def to_data(self) -> dict[str, Any]:
        return asdict(self)


def loop_of(item: WorkItem) -> Loop:
    data = dict(item.data.get("loop", {}))
    data["notes"] = tuple(data.get("notes", ()))
    return Loop(**data)


def save(
    store: StateStore, item_id: str, state: str, loop: Loop, *, cause: str
) -> None:
    item = store.work_item(item_id)
    assert item is not None
    store.update_work_item(
        item_id,
        position=state,
        data={**item.data, "loop": loop.to_data()},
        cause=cause,
    )


def item_for_thread(store: StateStore, thread: str) -> WorkItem | None:
    for item in store.work_items("open"):
        if loop_of(item).thread == thread:
            return item
    return None


def item_for_issue(store: StateStore, issue: int) -> WorkItem | None:
    """Any item, open or closed, recorded by this issue: intake never takes
    an issue twice (D1)."""
    for item in store.work_items():
        if loop_of(item).issue == issue:
            return item
    return None