# Copyright (C) 2026 Danilo M. <danix@danix.xyz>  GPL-2.0-only
import calendar
from datetime import date
from decimal import Decimal, InvalidOperation
from firefly_cli import registry, output
from firefly_cli.errors import FireflyError


def _current_month():
    """(first, last) ISO dates for the current calendar month."""
    today = date.today()
    last_day = calendar.monthrange(today.year, today.month)[1]
    first = today.replace(day=1).isoformat()
    last = today.replace(day=last_day).isoformat()
    return first, last


def _spent_scalar(budget_obj):
    """Sum a budget's nested `spent` array into a single number (for --human).
    Firefly sends spent as a per-currency list of {sum: "-12.34", ...}; we sum
    the sums. JSON output is untouched; this only feeds the table view."""
    total = Decimal(0)
    for entry in budget_obj.get("spent") or []:
        try:
            total += Decimal(str(entry.get("sum", 0)))
        except (TypeError, InvalidOperation):
            pass
    return f"{total:.2f}"


def _list_args(p):
    p.add_argument("--start", default=None, help="YYYY-MM-DD (default: 1st of this month)")
    p.add_argument("--end", default=None, help="YYYY-MM-DD (default: last of this month)")

@registry.command("budget list", help="list budgets with spent for a period (default: current month)", args=_list_args)
def cmd_list(args, ctx):
    first, last = _current_month()
    params = {"start": args.start or first, "end": args.end or last}
    resp = ctx.client.request("GET", "/api/v1/budgets", params=params)
    rows = output.unwrap(resp)
    if ctx.human and isinstance(rows, list):
        # Replace the nested spent array with a scalar so the table shows it.
        rows = [{**r, "spent": _spent_scalar(r)} for r in rows]
    output.emit(rows, human=ctx.human)
    return 0


def _create_args(p):
    p.add_argument("name", help="budget name (must be unique)")
    g = p.add_mutually_exclusive_group()
    g.add_argument("--active", dest="active", action="store_true", default=True,
                   help="create active (default)")
    g.add_argument("--inactive", dest="active", action="store_false",
                   help="create inactive")
    p.add_argument("--currency", default=None, help="auto-budget currency code, e.g. EUR")
    p.add_argument("--auto-budget-amount", dest="auto_budget_amount", default=None,
                   help="recurring auto-budget amount")
    p.add_argument("--auto-budget-period", dest="auto_budget_period", default=None,
                   help="daily|weekly|monthly|quarterly|half_year|yearly")
    p.add_argument("--auto-budget-type", dest="auto_budget_type", default=None,
                   help="reset|rollover|adjusted|none")

@registry.command("budget create", help="create a budget", args=_create_args)
def cmd_create(args, ctx):
    body = {"name": args.name, "active": args.active}
    if args.auto_budget_amount is not None:
        body["auto_budget_amount"] = str(args.auto_budget_amount)
    if args.auto_budget_period is not None:
        body["auto_budget_period"] = args.auto_budget_period
    if args.auto_budget_type is not None:
        body["auto_budget_type"] = args.auto_budget_type
    if args.currency:
        body["currency_code"] = args.currency
    resp = ctx.client.request("POST", "/api/v1/budgets", body=body)
    output.emit(output.unwrap(resp), human=ctx.human)
    return 0


def _ref_arg(p):
    p.add_argument("ref", help="budget name or id")

def _delete_args(p):
    _ref_arg(p)
    p.add_argument("--yes", action="store_true", help="confirm deletion (required)")

@registry.command("budget delete", help="delete a budget by name or id (requires --yes)", args=_delete_args)
def cmd_delete(args, ctx):
    if not args.yes:
        raise FireflyError("budget delete needs --yes to confirm.")
    b = ctx.resolver.budget(args.ref)
    ctx.client.request("DELETE", f"/api/v1/budgets/{b['id']}")
    output.emit({"deleted": b["id"], "name": b.get("name")}, human=ctx.human)
    return 0

def _set_active(ctx, ref, active):
    b = ctx.resolver.budget(ref)
    resp = ctx.client.request("PUT", f"/api/v1/budgets/{b['id']}",
                              body={"active": active})
    output.emit(output.unwrap(resp), human=ctx.human)
    return 0

def _update_args(p):
    _ref_arg(p)
    p.add_argument("--name", default=None, help="new budget name")
    p.add_argument("--currency", default=None, help="auto-budget currency code, e.g. EUR")
    p.add_argument("--auto-budget-amount", dest="auto_budget_amount", default=None,
                   help="recurring auto-budget amount")
    p.add_argument("--auto-budget-period", dest="auto_budget_period", default=None,
                   help="daily|weekly|monthly|quarterly|half_year|yearly")
    p.add_argument("--auto-budget-type", dest="auto_budget_type", default=None,
                   help="reset|rollover|adjusted|none")

@registry.command("budget update", help="rename a budget and/or edit its auto-budget fields (name or id)", args=_update_args)
def cmd_update(args, ctx):
    b = ctx.resolver.budget(args.ref)
    body = {}
    if args.name is not None:
        body["name"] = args.name
    if args.auto_budget_amount is not None:
        body["auto_budget_amount"] = str(args.auto_budget_amount)
    if args.auto_budget_period is not None:
        body["auto_budget_period"] = args.auto_budget_period
    if args.auto_budget_type is not None:
        body["auto_budget_type"] = args.auto_budget_type
    if args.currency:
        body["currency_code"] = args.currency
    if not body:
        raise FireflyError("budget update: nothing to change; pass at least one field")
    resp = ctx.client.request("PUT", f"/api/v1/budgets/{b['id']}", body=body)
    output.emit(output.unwrap(resp), human=ctx.human)
    return 0


@registry.command("budget enable", help="mark a budget active", args=_ref_arg)
def cmd_enable(args, ctx):
    return _set_active(ctx, args.ref, True)

@registry.command("budget disable", help="mark a budget inactive", args=_ref_arg)
def cmd_disable(args, ctx):
    return _set_active(ctx, args.ref, False)


@registry.command("budget limit-list", help="list a budget's limits (name or id)", args=_ref_arg)
def cmd_limit_list(args, ctx):
    b = ctx.resolver.budget(args.ref)
    resp = ctx.client.request("GET", f"/api/v1/budgets/{b['id']}/limits")
    output.emit(output.unwrap(resp), human=ctx.human)
    return 0

def _limit_set_args(p):
    _ref_arg(p)
    p.add_argument("--amount", required=True, help="limit amount (positive)")
    p.add_argument("--start", default=None, help="YYYY-MM-DD (default: 1st of this month)")
    p.add_argument("--end", default=None, help="YYYY-MM-DD (default: last of this month)")
    p.add_argument("--currency", default=None, help="currency code, e.g. EUR")

@registry.command("budget limit-set", help="set (create) a spending limit for a budget over a period", args=_limit_set_args)
def cmd_limit_set(args, ctx):
    b = ctx.resolver.budget(args.ref)
    first, last = _current_month()
    body = {"amount": str(args.amount),
            "start": args.start or first,
            "end": args.end or last}
    if args.currency:
        body["currency_code"] = args.currency
    resp = ctx.client.request("POST", f"/api/v1/budgets/{b['id']}/limits", body=body)
    output.emit(output.unwrap(resp), human=ctx.human)
    return 0