"""The derived group-to-role map. Roles come only from AD groups; nothing in the app can change the map.

The department table is seed data (migration 0002). The map is built from it plus `PS-Admins`.
`DEPARTMENTS` here mirrors the seed so the map works without a database (CLI, tests).
"""

from __future__ import annotations

from collections.abc import Iterable, Sequence
from dataclasses import dataclass
from typing import Any

ADMIN_GROUP = "PS-Admins"
SHOP_LEVELS = ("worker", "lead", "supervisor")
SCREENS = ("clerical", "warehouse", "supervisor", "stall", "qc", "pm", "admin")

# Office role kinds per support department code: (member kind, supervisor kind or None)
OFFICE_KINDS: dict[str, tuple[str, str | None]] = {
    "CL": ("clerical", "clerical_supervisor"),
    "WH": ("warehouse", "warehouse_supervisor"),
    "QC": ("qc", "qc_supervisor"),
    "PM": ("pm", None),
}
OFFICE_DEPT: dict[str, str] = {kind: code for code, kinds in OFFICE_KINDS.items() for kind in kinds if kind}
ROLE_KINDS = (
    "admin",
    "clerical",
    "clerical_supervisor",
    "warehouse",
    "warehouse_supervisor",
    "qc",
    "qc_supervisor",
    "pm",
    "shop_worker",
    "shop_lead",
    "shop_supervisor",
)


@dataclass(frozen=True)
class Department:
    code: str
    slug: str
    name: str
    kind: str  # support | shop
    sort: int
    supervisor_group: bool = True
    active: bool = True


def _stations(prefix: str, n: int) -> tuple[str, ...]:
    return tuple(f"{prefix} {i}" for i in range(1, n + 1))


# code, slug, name, kind, supervisor_group, stations. Mirrors the seed in migration 0002.
SEED: tuple[tuple[str, str, str, str, bool, tuple[str, ...]], ...] = (
    ("CL", "Clerical", "Clerical", "support", True, ()),
    ("WH", "Warehouse", "Warehouse", "support", True, ()),
    ("QC", "QC", "Q.C.", "support", True, ()),
    ("PM", "ProjectMgmt", "Project Management", "support", False, ()),
    ("01", "Layout", "Layout", "shop", True, _stations("Station", 4)),
    ("02", "SouthLayout", "PESCO South Layout", "shop", True, _stations("Station", 4)),
    ("03", "WeldParts", "Weld Parts", "shop", True, _stations("Stall", 6)),
    ("04", "SouthWeld", "PESCO South Weld", "shop", True, _stations("Stall", 6)),
    ("05", "SouthWeldSS", "PESCO South Weld SS", "shop", True, _stations("Stall", 6)),
    ("06", "CodeBldg2", "Code Bldg 2", "shop", True, _stations("Stall", 6)),
    ("07", "CodeBldg3", "Code Bldg 3", "shop", True, _stations("Stall", 6)),
    ("08", "Subassembly", "Subassembly", "shop", True, _stations("Station", 4)),
    ("09", "Hydro", "Hydro", "shop", True, ("Hydro Bay 1", "Hydro Bay 2")),
    ("10", "WeldAssembly", "Weld Assembly", "shop", True, _stations("Stall", 6)),
    ("11", "FinalAssyNorth", "Final Assembly - North", "shop", True, _stations("Station", 4)),
    ("12", "FinalAssySouth", "Final Assembly - South", "shop", True, _stations("Station", 4)),
    ("13", "PaintSandblast", "Paint-Sandblast", "shop", True, ("Blast Booth", "Paint Booth 1", "Paint Booth 2")),
    ("14", "Electrical", "Electrical", "shop", True, _stations("Station", 4)),
)

DEPARTMENTS: tuple[Department, ...] = tuple(
    Department(code, slug, name, kind, (i + 1) * 10, sup) for i, (code, slug, name, kind, sup, _) in enumerate(SEED)
)


@dataclass(frozen=True)
class Role:
    """One role: a kind and its department code (None for admin)."""

    kind: str
    dept_code: str | None = None

    def __str__(self) -> str:
        if self.kind.startswith("shop_"):
            return f"shop:{self.dept_code}:{self.kind.removeprefix('shop_')}"
        return self.kind


def parse_role(text: str) -> Role:
    """`"shop:03:supervisor"` -> Role("shop_supervisor", "03"); `"clerical"` -> Role("clerical", "CL")."""
    if text.startswith("shop:"):
        parts = text.split(":")
        if len(parts) != 3 or parts[2] not in SHOP_LEVELS or not parts[1]:
            raise ValueError(f"bad role {text!r}")
        return Role(f"shop_{parts[2]}", parts[1])
    if text == "admin":
        return Role("admin", None)
    if text in OFFICE_DEPT:
        return Role(text, OFFICE_DEPT[text])
    raise ValueError(f"bad role {text!r}")


def role_from_row(kind: str, dept_code: str | None) -> str:
    """The role string for a `user_roles` row."""
    return str(Role(kind, dept_code))


def _level(r: Role) -> int:
    return SHOP_LEVELS.index(r.kind.removeprefix("shop_"))


class GroupMap:
    """Group name -> Role for a list of departments. Matching is case-insensitive on the cn."""

    def __init__(self, departments: Sequence[Department]):
        self.departments = sorted(departments, key=lambda d: (0 if d.kind == "support" else 1, d.sort, d.code))
        self.entries: list[tuple[str, Role]] = [(ADMIN_GROUP, Role("admin"))]
        for d in self.departments:
            if d.kind != "support" or d.code not in OFFICE_KINDS:
                continue
            member, sup = OFFICE_KINDS[d.code]
            self.entries.append((f"PS-{d.slug}", Role(member, d.code)))
            if d.supervisor_group and sup:
                self.entries.append((f"PS-{d.slug}-Supervisor", Role(sup, d.code)))
        for d in self.departments:
            if d.kind == "shop":
                for level in SHOP_LEVELS:
                    self.entries.append((f"PS-{d.code}-{d.slug}-{level.capitalize()}", Role(f"shop_{level}", d.code)))
        self._by_lower = {name.lower(): (name, role) for name, role in self.entries}
        self._order = {str(role): i for i, (_, role) in enumerate(self.entries)}

    def names(self) -> list[str]:
        return [name for name, _ in self.entries]

    def role_for(self, name: str) -> Role | None:
        hit = self._by_lower.get(name.strip().lower())
        return hit[1] if hit else None

    def canonical(self, name: str) -> str | None:
        """The map's spelling of a group name, or None when it is not mapped."""
        hit = self._by_lower.get(name.strip().lower())
        return hit[0] if hit else None

    def sort_roles(self, roles: Iterable[str]) -> list[str]:
        return sorted(set(roles), key=lambda s: (self._order.get(s, 10_000), s))

    def roles(self, names: Iterable[str]) -> list[str]:
        """Role strings for a set of group names: the union, highest shop level per department."""
        found = {r for n in names if (r := self.role_for(n)) is not None}
        best: dict[str, Role] = {}
        out: set[str] = set()
        for r in found:
            if r.kind.startswith("shop_"):
                code = r.dept_code or ""
                cur = best.get(code)
                if cur is None or _level(r) > _level(cur):
                    best[code] = r
            else:
                out.add(str(r))
        out.update(str(r) for r in best.values())
        return self.sort_roles(out)


_default = GroupMap(DEPARTMENTS)


def current() -> GroupMap:
    return _default


def use_departments(departments: Sequence[Department]) -> GroupMap:
    """Replace the process-wide map (the app calls this at startup with the departments table)."""
    global _default
    _default = GroupMap(departments)
    return _default


def load_departments(conn: Any) -> list[Department]:
    rows = conn.execute(
        "SELECT code, slug, name, kind::text, sort, supervisor_group, active FROM departments ORDER BY sort, code"
    ).fetchall()
    return [Department(r[0], r[1], r[2], r[3], r[4], r[5], r[6]) for r in rows]


def group_names() -> list[str]:
    """The mapped group names in contract order: PS-Admins, CL, WH, QC, PM, then shop 01..14."""
    return _default.names()


def role_for_group(name: str) -> Role | None:
    return _default.role_for(name)


def roles_from_groups(names: Iterable[str]) -> list[str]:
    return _default.roles(names)


def mapped_groups(names: Iterable[str]) -> list[str]:
    """The map's spelling of every mapped name in `names`, in map order, without duplicates."""
    keep = {c for n in names if (c := _default.canonical(n))}
    return [n for n in _default.names() if n in keep]


def screens_for(roles: Iterable[str]) -> list[str]:
    """The screens a role set may open. Admin gets every screen."""
    have: set[str] = set()
    for r in roles:
        if r == "admin":
            have.update(SCREENS)
        elif r.startswith("clerical"):
            have.add("clerical")
        elif r.startswith("warehouse"):
            have.add("warehouse")
        elif r.startswith("qc"):
            have.add("qc")
        elif r == "pm":
            have.add("pm")
        elif r.startswith("shop:"):
            have.add("stall")
            if r.endswith((":lead", ":supervisor")):
                have.add("supervisor")
    return [s for s in SCREENS if s in have]


# The label of a screen, shown beside a name in presence ("Also in this packet now: Ann (Q.C.)").
SCREEN_LABELS: dict[str, str] = {
    "clerical": "Clerical",
    "warehouse": "Warehouse",
    "supervisor": "Supervisor",
    "stall": "Weld Stall",
    "qc": "Q.C.",
    "pm": "Project Mgmt",
    "admin": "Admin",
}


def _role_text(role: str) -> str:
    if role == "admin":
        return "Admin"
    if role.startswith("clerical"):
        return "Clerical"
    if role.startswith("warehouse"):
        return "Warehouse"
    if role.startswith("qc"):
        return "Q.C."
    if role == "pm":
        return "Project Mgmt"
    if role.startswith("shop:"):
        return "Supervisor" if role.endswith((":lead", ":supervisor")) else "Weld Stall"
    return ""


def role_label(roles: Iterable[str]) -> str:
    """The person's primary role as a screen label: the first role in map order (admin, Clerical, Warehouse, Q.C.,
    PM, then the shop departments). Empty when there is none."""
    for r in _default.sort_roles(roles):
        text = _role_text(r)
        if text:
            return text
    return ""


def is_admin(roles: Iterable[str]) -> bool:
    return "admin" in set(roles)


def is_shop_supervisor(roles: Iterable[str]) -> bool:
    return any(r.startswith("shop:") and r.endswith(":supervisor") for r in roles)