"""Sprint commit proposals — ADP P6 / agile_iteration."""

from __future__ import annotations

from typing import Any

from steering.eval_context import SteeringEvalContext

COMMITTABLE_STATUSES = frozenset({"new", "triaged", "accepted"})
PLANABLE_CYCLE_STATUSES = frozenset({"planned", "active"})
OPEN_ACTION = frozenset({"open", "ready", "in_progress", "blocked", "review_required"})

_PRIORITY_RANK = {"critical": 0, "high": 1, "normal": 2, "low": 3}
_KIND_RANK = {"bug": 0, "issue": 1, "incident": 1, "story": 2, "idea": 3}

_REASON_LABELS = {
    "bug_critical": "Kritischer Bug — Sprint-Priorität",
    "bug_high_priority": "Bug mit hoher Priorität",
    "bug_default": "Bug — vor Features priorisieren",
    "issue_default": "Issue/Störung im Eingang",
    "story_high_priority": "Story mit hoher Priorität",
    "story_ready": "Story bereit zum Commit",
    "idea_default": "Idee im Eingang",
}


def _resolve_target_work_cycle(
    ctx: SteeringEvalContext,
) -> dict[str, Any] | None:
    cycles = [
        c for c in ctx.work_cycles if c.get("status") in PLANABLE_CYCLE_STATUSES
    ]
    if not cycles:
        return None

    if ctx.horizon.work_cycle_id:
        match = next(
            (c for c in cycles if str(c["id"]) == str(ctx.horizon.work_cycle_id)),
            None,
        )
        if match:
            return match

    planned = sorted(
        [c for c in cycles if c.get("status") == "planned"],
        key=lambda c: (c.get("sort_order", 0), str(c["id"])),
    )
    if planned:
        return planned[0]

    active = sorted(
        [c for c in cycles if c.get("status") == "active"],
        key=lambda c: (c.get("sort_order", 0), str(c["id"])),
    )
    return active[0] if active else None


def _reason_code(item: dict[str, Any]) -> str:
    kind = item.get("item_kind") or "story"
    priority = item.get("priority") or "normal"
    if kind == "bug":
        if priority == "critical":
            return "bug_critical"
        if priority == "high":
            return "bug_high_priority"
        return "bug_default"
    if kind in ("issue", "incident"):
        return "issue_default"
    if kind == "idea":
        return "idea_default"
    if priority in ("critical", "high"):
        return "story_high_priority"
    return "story_ready"


def _sort_key(item: dict[str, Any]) -> tuple:
    kind = item.get("item_kind") or "story"
    priority = item.get("priority") or "normal"
    return (
        _KIND_RANK.get(kind, 9),
        _PRIORITY_RANK.get(priority, 9),
        item.get("sort_order") if item.get("sort_order") is not None else 9999,
        (item.get("title") or "").lower(),
    )


def propose_sprint_commit(ctx: SteeringEvalContext) -> list[dict[str, Any]]:
    """Ranked backlog items suggested for sprint commit — no auto-mutation."""
    target = _resolve_target_work_cycle(ctx)
    if not target:
        return []

    vocabulary = ctx.backlog_vocabulary
    convertible = frozenset(vocabulary.get("convertible_kinds") or ["story", "bug", "issue"])

    candidates = [
        item
        for item in ctx.backlog_items
        if item.get("status") in COMMITTABLE_STATUSES
        and item.get("item_kind") != "epic"
        and (item.get("item_kind") or "story") in convertible
    ]
    if not candidates:
        return []

    ranked = sorted(candidates, key=_sort_key)
    cycle_id = str(target["id"])
    cycle_title = target.get("title") or "Sprint"

    proposals: list[dict[str, Any]] = []
    for rank, item in enumerate(ranked[:20], start=1):
        reason = _reason_code(item)
        kind = item.get("item_kind") or "story"
        proposals.append(
            {
                "proposal_key": "sprint_commit",
                "scope_type": "backlog_item",
                "scope_id": str(item["id"]),
                "rank": rank,
                "reason_code": reason,
                "summary": _REASON_LABELS.get(reason, "Zum Sprint committen"),
                "title": item.get("title") or "Backlog-Item",
                "item_kind": kind,
                "priority": item.get("priority") or "normal",
                "work_cycle_id": cycle_id,
                "work_cycle_title": cycle_title,
                "initiative_id": ctx.initiative_id,
                "confidence": "heuristic",
                "data_source": "steering_kernel",
            }
        )

    return proposals


def sprint_commit_attention_items(
    *,
    initiative_id: str,
    proposals: list[dict[str, Any]],
    actions: list[dict[str, Any]],
) -> list[dict[str, Any]]:
    """Attention when sprint has room for proposed commits."""
    if not proposals:
        return []

    target_id = proposals[0].get("work_cycle_id")
    if not target_id:
        return []

    sprint_actions = [
        a
        for a in actions
        if a.get("work_cycle_id") and str(a["work_cycle_id"]) == str(target_id)
    ]
    open_in_sprint = sum(1 for a in sprint_actions if a.get("status") in OPEN_ACTION)

    items: list[dict[str, Any]] = []
    cycle_title = proposals[0].get("work_cycle_title") or "Sprint"

    if open_in_sprint == 0:
        items.append(
            {
                "kind": "sprint_commit_suggested",
                "severity": "info",
                "title": cycle_title,
                "summary": (
                    f"{len(proposals)} Item(s) im Eingang — "
                    "Kernel schlägt Sprint-Commit vor"
                ),
                "scope_type": "work_cycle",
                "scope_id": str(target_id),
                "initiative_id": initiative_id,
                "reason_code": "sprint_commit_suggested",
                "data_source": "sprint_commit_proposal",
            }
        )

    return items