"""Projects: list, read, create, field edits, renumber, soft delete; and the number lookup.

Reads need any signed-in session (PM included). Writes need Clerical (clerical or clerical_supervisor);
renumber and delete need clerical_supervisor. An admin outside those roles may do any of them with an
`it_reason` of at least 8 characters, kept on the audit row.

The router has no prefix because it also serves GET /api/lookup/number; every path starts with /api.
"""

from __future__ import annotations

from typing import Any

from fastapi import APIRouter, Depends, Query
from pydantic import BaseModel, ConfigDict, Field

from ..domain import projects as dom
from ..text import reason_ok
from .deps import Db, Principal, current_principal, get_db, require_password_session
from .errors import ApiError

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

PREFIX = "/api/projects"
CLERICAL = frozenset({"clerical", "clerical_supervisor"})
CLERICAL_SUP = frozenset({"clerical_supervisor"})

# Generous input caps; clean_text cuts every value to its field limit.
TEXT = 4000


def authorize(p: Principal, *, supervisor: bool, it_reason: str | None) -> dom.Who:
    """The write check. Returns who is writing; it_reason is set only for an admin acting outside their roles."""
    need = CLERICAL_SUP if supervisor else CLERICAL
    if need & set(p.roles):
        return dom.Who(user_id=p.user_id, session_id=p.session_id, role_snapshot=p.role_snapshot, ip=p.ip)
    if p.is_admin:
        require_password_session(p)
        why = reason_ok(it_reason)
        if why is None:
            raise ApiError(400, "it_reason_required", "Give an IT reason of at least 8 characters.")
        return dom.Who(
            user_id=p.user_id, session_id=p.session_id, role_snapshot=p.role_snapshot, ip=p.ip, it_reason=why
        )
    if supervisor:
        raise ApiError(403, "forbidden", "Only a Clerical Supervisor can do this.")
    raise ApiError(403, "forbidden", "Only Clerical can change projects and units.")


class ProjectCreate(BaseModel):
    number: str = Field(max_length=200)
    name: str | None = Field(None, max_length=TEXT)
    customer: str | None = Field(None, max_length=TEXT)
    po: str | None = Field(None, max_length=TEXT)
    due: str | None = Field(None, max_length=40)
    status: str | None = Field(None, max_length=20)
    notes: str | None = Field(None, max_length=TEXT)
    it_reason: str | None = Field(None, max_length=TEXT)


class FieldCas(BaseModel):
    """`{set, base}`: the new values and what the client last saw for them."""

    model_config = ConfigDict(populate_by_name=True)

    values: dict[str, Any] = Field(alias="set")
    base: dict[str, Any] = Field(default_factory=dict)
    it_reason: str | None = Field(None, max_length=TEXT)


class RenumberProject(BaseModel):
    number: str = Field(max_length=200)
    reason: str | None = Field(None, max_length=TEXT)
    it_reason: str | None = Field(None, max_length=TEXT)


class ReasonBody(BaseModel):
    reason: str | None = Field(None, max_length=TEXT)
    it_reason: str | None = Field(None, max_length=TEXT)


class UnitsCreate(BaseModel):
    lot: str | None = Field(None, max_length=40)
    lots: list[str] | None = Field(None, max_length=dom.MAX_UNITS_AT_ONCE)
    count: int | None = None
    start: str | None = Field(None, max_length=40)
    name: str | None = Field(None, max_length=TEXT)
    due: str | None = Field(None, max_length=40)
    status: str | None = Field(None, max_length=20)
    notes: str | None = Field(None, max_length=TEXT)
    it_reason: str | None = Field(None, max_length=TEXT)


@router.get(PREFIX)
def list_projects(
    p: Principal = Depends(current_principal),  # noqa: B008
    d: Db = Depends(get_db),  # noqa: B008
    q: str = Query("", max_length=200),
    status: str = Query("active", max_length=20),
) -> list[dict[str, Any]]:
    return dom.list_projects(d.conn, q=q, status=status)


@router.post(PREFIX, status_code=201)
def create_project(
    body: ProjectCreate,
    p: Principal = Depends(current_principal),  # noqa: B008
    d: Db = Depends(get_db),  # noqa: B008
) -> dict[str, Any]:
    who = authorize(p, supervisor=False, it_reason=body.it_reason)
    return dom.create_project(d.conn, who, body.model_dump())


@router.get(PREFIX + "/{project_id}")
def project_detail(
    project_id: int,
    p: Principal = Depends(current_principal),  # noqa: B008
    d: Db = Depends(get_db),  # noqa: B008
) -> dict[str, Any]:
    return dom.project_detail(d.conn, project_id)


@router.patch(PREFIX + "/{project_id}")
def update_project(
    project_id: int,
    body: FieldCas,
    p: Principal = Depends(current_principal),  # noqa: B008
    d: Db = Depends(get_db),  # noqa: B008
) -> dict[str, Any]:
    who = authorize(p, supervisor=False, it_reason=body.it_reason)
    return dom.update_project(d.conn, who, project_id, body.values, body.base)


@router.post(PREFIX + "/{project_id}/renumber")
def renumber_project(
    project_id: int,
    body: RenumberProject,
    p: Principal = Depends(current_principal),  # noqa: B008
    d: Db = Depends(get_db),  # noqa: B008
) -> dict[str, Any]:
    who = authorize(p, supervisor=True, it_reason=body.it_reason)
    return dom.renumber_project(d.conn, who, project_id, body.number, body.reason)


@router.delete(PREFIX + "/{project_id}")
def remove_project(
    project_id: int,
    body: ReasonBody,
    p: Principal = Depends(current_principal),  # noqa: B008
    d: Db = Depends(get_db),  # noqa: B008
) -> dict[str, Any]:
    who = authorize(p, supervisor=True, it_reason=body.it_reason)
    return dom.remove_project(d.conn, who, project_id, body.reason)


@router.post(PREFIX + "/{project_id}/units", status_code=201)
def create_units(
    project_id: int,
    body: UnitsCreate,
    p: Principal = Depends(current_principal),  # noqa: B008
    d: Db = Depends(get_db),  # noqa: B008
) -> list[dict[str, Any]]:
    who = authorize(p, supervisor=False, it_reason=body.it_reason)
    return dom.create_units(d.conn, who, project_id, body.model_dump())


@router.get("/api/lookup/number")
def lookup_number(
    p: Principal = Depends(current_principal),  # noqa: B008
    d: Db = Depends(get_db),  # noqa: B008
    n: str = Query(..., min_length=1, max_length=40),
) -> dict[str, Any]:
    found = dom.lookup(d.conn, n)
    if found is None:
        raise ApiError(404, "not_found", "No project or unit has that number.")
    return found