"""Roadmap API — AP1.4."""

from __future__ import annotations

from datetime import date
from typing import Any, Literal, Optional

from capabilities import require_capability
from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel, Field
from schemas.schedule_payload import SchedulePayload
from services import roadmap as roadmap_service
from services import roadmap_criteria as criteria_service
from services import roadmap_plan_snapshot as snapshot_service
from tenant_context import TenantContext

router = APIRouter(tags=["roadmap"])


class RoadmapItemCreateRequest(BaseModel):
    title: str = Field(min_length=1, max_length=255)
    item_type: Literal["milestone", "review_gate", "maturity_stage", "work_cycle", "join_gate"] = "milestone"
    goal_description: str = ""
    definition_of_done: list[Any] = Field(default_factory=list)
    status: Literal[
        "planned", "active", "at_risk", "reached", "moved", "discarded"
    ] = "planned"
    sequencing_mode: Literal["sequential", "parallel", "optional"] = "sequential"
    target_date: Optional[date] = None
    sort_order: int = 0
    strand_project_id: Optional[str] = None
    initial_criterion_title: Optional[str] = Field(default=None, max_length=500)


class RoadmapItemUpdateRequest(BaseModel):
    title: Optional[str] = Field(default=None, min_length=1, max_length=255)
    item_type: Optional[Literal["milestone", "review_gate", "maturity_stage", "work_cycle", "join_gate"]] = None
    goal_description: Optional[str] = None
    definition_of_done: Optional[list[Any]] = None
    status: Optional[
        Literal["planned", "active", "at_risk", "reached", "moved", "discarded"]
    ] = None
    sequencing_mode: Optional[Literal["sequential", "parallel", "optional"]] = None
    target_date: Optional[date] = None
    clear_target_date: bool = False
    sort_order: Optional[int] = None
    strand_project_id: Optional[str] = None
    clear_strand_project: bool = False


class DependencyCreateRequest(BaseModel):
    to_item_id: str
    dependency_type: Literal[
        "requires", "blocks", "related", "parallel_group", "optional_branch"
    ] = "requires"
    group_key: Optional[str] = Field(default=None, max_length=128)


class CriterionCreateRequest(BaseModel):
    title: str = Field(min_length=1, max_length=500)
    description: str = ""
    criterion_kind: Literal["manual", "evidence_required", "review_required", "metric"] = "manual"
    verification_hint: str = ""
    sort_order: int = 0


class CriterionUpdateRequest(BaseModel):
    title: Optional[str] = Field(default=None, min_length=1, max_length=500)
    description: Optional[str] = None
    criterion_kind: Optional[
        Literal["manual", "evidence_required", "review_required", "metric"]
    ] = None
    verification_hint: Optional[str] = None
    sort_order: Optional[int] = None
    change_reason: str = ""


class CriterionWaiveDeferRequest(BaseModel):
    decision_title: str = Field(min_length=1, max_length=255)
    decision_description: str = ""


class CriterionSatisfyRequest(BaseModel):
    evidence_id: Optional[str] = None


class ReopenRequest(BaseModel):
    reason: str = ""


class GatePracticeCreateRequest(BaseModel):
    title: str = Field(min_length=1, max_length=255)
    description: str = ""
    status: Literal["active", "paused", "ended"] = "active"
    interval_days: int = Field(default=1, gt=0)
    schedule: Optional[SchedulePayload] = None


class PlanSnapshotCreateRequest(BaseModel):
    reason: str = Field(default="", max_length=2000)


initiative_router = APIRouter(prefix="/api/initiatives", tags=["roadmap"])
items_router = APIRouter(prefix="/api/roadmap-items", tags=["roadmap"])
deps_router = APIRouter(prefix="/api/roadmap-dependencies", tags=["roadmap"])


@initiative_router.get("/{initiative_id}/roadmap")
def get_initiative_roadmap(
    initiative_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.read")),
):
    try:
        roadmap = roadmap_service.get_roadmap_for_initiative(
            tenant_id=ctx.tenant_id, initiative_id=initiative_id
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc
    if not roadmap:
        return {"initiative_id": initiative_id, "items": []}
    items = roadmap_service.list_roadmap_items_for_initiative(
        tenant_id=ctx.tenant_id, initiative_id=initiative_id
    )
    return {**roadmap, "items": items}


@initiative_router.get("/{initiative_id}/roadmap/items")
def list_initiative_roadmap_items(
    initiative_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.read")),
):
    try:
        return roadmap_service.list_roadmap_items_for_initiative(
            tenant_id=ctx.tenant_id, initiative_id=initiative_id
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@initiative_router.get("/{initiative_id}/roadmap/dependencies")
def list_initiative_roadmap_dependencies(
    initiative_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.read")),
):
    try:
        return roadmap_service.list_dependencies_for_initiative(
            tenant_id=ctx.tenant_id, initiative_id=initiative_id
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@initiative_router.get("/{initiative_id}/roadmap/criteria-progress")
def list_initiative_roadmap_criteria_progress(
    initiative_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.read")),
):
    try:
        return criteria_service.criteria_progress_for_initiative(
            tenant_id=ctx.tenant_id, initiative_id=initiative_id
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@initiative_router.get("/{initiative_id}/roadmap/graph-state")
def get_initiative_roadmap_graph_state(
    initiative_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.read")),
):
    try:
        from steering.graph.roadmap_engine import load_initiative_graph_state

        return load_initiative_graph_state(
            tenant_id=ctx.tenant_id, initiative_id=initiative_id
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@initiative_router.get("/{initiative_id}/roadmap/progression-state")
def get_initiative_progression_state(
    initiative_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.read")),
):
    try:
        from services.progression_graph import compute_progression_state

        return compute_progression_state(
            tenant_id=ctx.tenant_id, initiative_id=initiative_id
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@initiative_router.get("/{initiative_id}/roadmap/plan-ist-view")
def get_initiative_plan_ist_view(
    initiative_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.read")),
):
    try:
        from steering.graph.plan_ist import load_plan_ist_view

        return load_plan_ist_view(tenant_id=ctx.tenant_id, initiative_id=initiative_id)
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@initiative_router.get("/{initiative_id}/roadmap/plan-snapshots")
def list_initiative_plan_snapshots(
    initiative_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.read")),
):
    try:
        return snapshot_service.list_plan_snapshots(
            tenant_id=ctx.tenant_id, initiative_id=initiative_id
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@initiative_router.post("/{initiative_id}/roadmap/plan-snapshots", status_code=201)
def create_initiative_plan_snapshot(
    initiative_id: str,
    body: PlanSnapshotCreateRequest,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        return snapshot_service.create_plan_snapshot(
            tenant_id=ctx.tenant_id,
            initiative_id=initiative_id,
            reason=body.reason,
            user_id=ctx.user_id,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@initiative_router.post("/{initiative_id}/roadmap/items", status_code=201)
def create_initiative_roadmap_item(
    initiative_id: str,
    body: RoadmapItemCreateRequest,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        return roadmap_service.create_roadmap_item(
            tenant_id=ctx.tenant_id,
            initiative_id=initiative_id,
            user_id=ctx.user_id,
            title=body.title,
            item_type=body.item_type,
            goal_description=body.goal_description,
            definition_of_done=body.definition_of_done,
            status=body.status,
            sequencing_mode=body.sequencing_mode,
            target_date=body.target_date,
            sort_order=body.sort_order,
            strand_project_id=body.strand_project_id,
            initial_criterion_title=body.initial_criterion_title,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@items_router.get("/{item_id}")
def get_roadmap_item(
    item_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.read")),
):
    item = roadmap_service.get_roadmap_item(tenant_id=ctx.tenant_id, item_id=item_id)
    if not item:
        raise HTTPException(status_code=404, detail="RoadmapItem nicht gefunden")
    return item


@items_router.patch("/{item_id}")
def update_roadmap_item(
    item_id: str,
    body: RoadmapItemUpdateRequest,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        item = roadmap_service.update_roadmap_item(
            tenant_id=ctx.tenant_id,
            item_id=item_id,
            user_id=ctx.user_id,
            title=body.title,
            item_type=body.item_type,
            goal_description=body.goal_description,
            definition_of_done=body.definition_of_done,
            status=body.status,
            sequencing_mode=body.sequencing_mode,
            target_date=body.target_date,
            clear_target_date=body.clear_target_date,
            sort_order=body.sort_order,
            strand_project_id=body.strand_project_id,
            clear_strand_project=body.clear_strand_project,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc
    if not item:
        raise HTTPException(status_code=404, detail="RoadmapItem nicht gefunden")
    return item


@items_router.delete("/{item_id}", status_code=204)
def delete_roadmap_item(
    item_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        deleted = roadmap_service.delete_roadmap_item(
            tenant_id=ctx.tenant_id, item_id=item_id, user_id=ctx.user_id
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc
    if not deleted:
        raise HTTPException(status_code=404, detail="RoadmapItem nicht gefunden")


def _work_gate_or_400(*, tenant_id: str, item_id: str) -> dict[str, Any]:
    item = roadmap_service.get_roadmap_item(tenant_id=tenant_id, item_id=item_id)
    if not item:
        raise HTTPException(status_code=404, detail="RoadmapItem nicht gefunden")
    if item.get("item_type") == "join_gate":
        raise HTTPException(
            status_code=400,
            detail="Join-Gates haben kein Activity Set (Übungen)",
        )
    return item


@items_router.get("/{item_id}/practices")
def list_gate_practices(
    item_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.recurring.read")),
):
    from services import recurring as recurring_service

    item = _work_gate_or_400(tenant_id=ctx.tenant_id, item_id=item_id)
    try:
        return recurring_service.list_recurring_for_gate(
            tenant_id=ctx.tenant_id,
            initiative_id=str(item["initiative_id"]),
            gate_id=item_id,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@items_router.post("/{item_id}/practices", status_code=201)
def create_gate_practice(
    item_id: str,
    body: GatePracticeCreateRequest,
    ctx: TenantContext = Depends(require_capability("kairo.recurring.manage")),
):
    from services import recurring as recurring_service

    item = _work_gate_or_400(tenant_id=ctx.tenant_id, item_id=item_id)
    sched = body.schedule
    try:
        if sched:
            return recurring_service.create_recurring_element(
                tenant_id=ctx.tenant_id,
                initiative_id=str(item["initiative_id"]),
                title=body.title,
                description=body.description,
                status=body.status,
                schedule_kind=sched.schedule_kind,
                interval_days=sched.interval_days,
                weekday_mask=sched.weekday_mask,
                pause_until=sched.pause_until_date(),
                roadmap_item_id=item_id,
                user_id=ctx.user_id,
            )
        return recurring_service.create_recurring_element(
            tenant_id=ctx.tenant_id,
            initiative_id=str(item["initiative_id"]),
            title=body.title,
            description=body.description,
            status=body.status,
            interval_days=body.interval_days,
            roadmap_item_id=item_id,
            user_id=ctx.user_id,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@items_router.post("/{item_id}/verify-reached")
def verify_roadmap_item_reached(
    item_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        return roadmap_service.verify_reached(
            tenant_id=ctx.tenant_id, item_id=item_id, user_id=ctx.user_id
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@items_router.post("/{item_id}/reopen")
def reopen_roadmap_item(
    item_id: str,
    body: ReopenRequest,
    ctx: TenantContext = Depends(require_capability("kairo.roadmap.reopen")),
):
    try:
        return roadmap_service.reopen_roadmap_item(
            tenant_id=ctx.tenant_id,
            item_id=item_id,
            user_id=ctx.user_id,
            reason=body.reason,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@items_router.get("/{item_id}/criteria")
def list_roadmap_item_criteria(
    item_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.read")),
):
    try:
        progress = criteria_service.criteria_progress(
            tenant_id=ctx.tenant_id, item_id=item_id
        )
        items = criteria_service.list_criteria_for_item(
            tenant_id=ctx.tenant_id, item_id=item_id
        )
        return {"items": items, "progress": progress}
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@items_router.post("/{item_id}/criteria", status_code=201)
def create_roadmap_item_criterion(
    item_id: str,
    body: CriterionCreateRequest,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        return criteria_service.create_criterion(
            tenant_id=ctx.tenant_id,
            item_id=item_id,
            user_id=ctx.user_id,
            title=body.title,
            description=body.description,
            criterion_kind=body.criterion_kind,
            verification_hint=body.verification_hint,
            sort_order=body.sort_order,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@deps_router.delete("/{dependency_id}", status_code=204)
def delete_roadmap_dependency(
    dependency_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        roadmap_service.delete_dependency(
            tenant_id=ctx.tenant_id,
            dependency_id=dependency_id,
            user_id=ctx.user_id,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


criteria_router = APIRouter(prefix="/api/roadmap-criteria", tags=["roadmap"])


@criteria_router.patch("/{criterion_id}")
def update_roadmap_criterion(
    criterion_id: str,
    body: CriterionUpdateRequest,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        item = criteria_service.update_criterion(
            tenant_id=ctx.tenant_id,
            criterion_id=criterion_id,
            user_id=ctx.user_id,
            title=body.title,
            description=body.description,
            criterion_kind=body.criterion_kind,
            verification_hint=body.verification_hint,
            sort_order=body.sort_order,
            change_reason=body.change_reason,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc
    if not item:
        raise HTTPException(status_code=404, detail="Kriterium nicht gefunden")
    return item


@criteria_router.delete("/{criterion_id}", status_code=204)
def delete_roadmap_criterion(
    criterion_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        if not criteria_service.delete_criterion(
            tenant_id=ctx.tenant_id, criterion_id=criterion_id, user_id=ctx.user_id
        ):
            raise HTTPException(status_code=404, detail="Kriterium nicht gefunden")
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@criteria_router.post("/{criterion_id}/satisfy")
def satisfy_roadmap_criterion(
    criterion_id: str,
    body: CriterionSatisfyRequest,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        return criteria_service.satisfy_criterion(
            tenant_id=ctx.tenant_id,
            criterion_id=criterion_id,
            user_id=ctx.user_id,
            evidence_id=body.evidence_id,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@criteria_router.post("/{criterion_id}/waive")
def waive_roadmap_criterion(
    criterion_id: str,
    body: CriterionWaiveDeferRequest,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        return criteria_service.waive_criterion(
            tenant_id=ctx.tenant_id,
            criterion_id=criterion_id,
            user_id=ctx.user_id,
            decision_title=body.decision_title,
            decision_description=body.decision_description,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@criteria_router.post("/{criterion_id}/defer")
def defer_roadmap_criterion(
    criterion_id: str,
    body: CriterionWaiveDeferRequest,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        return criteria_service.defer_criterion(
            tenant_id=ctx.tenant_id,
            criterion_id=criterion_id,
            user_id=ctx.user_id,
            decision_title=body.decision_title,
            decision_description=body.decision_description,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@items_router.get("/{item_id}/dependencies")
def list_roadmap_item_dependencies(
    item_id: str,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.read")),
):
    try:
        return roadmap_service.list_dependencies(tenant_id=ctx.tenant_id, item_id=item_id)
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@items_router.post("/{item_id}/dependencies", status_code=201)
def add_roadmap_item_dependency(
    item_id: str,
    body: DependencyCreateRequest,
    ctx: TenantContext = Depends(require_capability("kairo.milestone.manage")),
):
    try:
        return roadmap_service.add_dependency(
            tenant_id=ctx.tenant_id,
            from_item_id=item_id,
            to_item_id=body.to_item_id,
            dependency_type=body.dependency_type,
            group_key=body.group_key,
            user_id=ctx.user_id,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc