"""ConnectVM rate card (INR) and pricing engine.

Model: flavor-based monthly pricing, prorated by billable hours in the
billing month. A VM present for the whole month pays its full flavor price;
created mid-month it prorates. Custom flavors (not on the card) are priced
from add-on unit rates. Volumes and floating IPs use add-on rates.
"""

# ---- Rate card: flavor monthly prices (INR) -------------------------------
# key = normalized flavor name ("B1 - Lite" / "B1 · Lite" -> "b1 lite")
FLAVOR_MONTHLY = {
    "m2 tiny": 1200.0,
    "m1 standard": 2303.0,
    "a1 nano": 2303.0,
    "b1 lite": 4607.0,
    "c1 core": 9215.0,
    "r1 medium": 27647.0,
    "s1 large": 34559.0,
    "t3 max": 43199.0,
    "d2 edge": 46079.0,
    "t2 xlarge": 62207.0,
    "w2 prime": 73727.0,
    "x1 elite": 92159.0,
}

# Card specs (vcpus, ram_mb, disk_gb) to detect spec drift on named flavors
FLAVOR_SPECS = {
    "m2 tiny": (1, 2048, 10),
    "m1 standard": (1, 4096, 20),
    "a1 nano": (2, 4096, 20),
    "b1 lite": (4, 8192, 40),
    "c1 core": (8, 16384, 80),
    "r1 medium": (16, 65536, 200),
    "s1 large": (24, 65536, 300),
    "t3 max": (32, 131072, 480),
    "d2 edge": (12, 32768, 100),
    "t2 xlarge": (32, 98304, 480),
    "w2 prime": (42, 131072, 500),
    "x1 elite": (64, 131072, 800),
}

# ---- Add-on rates (INR/month) ---------------------------------------------
ADDON_VCPU = 480.0          # per vCPU
ADDON_RAM_PER_GB = 192.0    # per GB RAM
ADDON_DISK_PER_GB = 9.6     # ₹96 per 10 GB SSD
FIP_MONTHLY = 300.0         # additional IPv4
SNAPSHOT_PER_10GB = 48.0    # not metered yet
LB_MONTHLY = 1440.0         # not metered yet (Octavia)
BACKUP_PER_10GB = 72.0      # not metered yet
BANDWIDTH_PER_GB = 1.80     # not metered yet

RATE_CARD_INFO = {
    "currency": "INR",
    "model": "flavor monthly price prorated by billable hours; "
             "custom flavors computed from add-on rates",
    "addon_rates_per_month": {
        "vcpu": ADDON_VCPU,
        "ram_gb": ADDON_RAM_PER_GB,
        "ssd_gb": ADDON_DISK_PER_GB,
        "floating_ip": FIP_MONTHLY,
    },
    "not_yet_metered": {
        "snapshot_per_10gb": SNAPSHOT_PER_10GB,
        "load_balancer": LB_MONTHLY,
        "backup_per_10gb": BACKUP_PER_10GB,
        "bandwidth_per_gb": BANDWIDTH_PER_GB,
    },
}


def normalize_flavor(name: str) -> str:
    for ch in ("·", "-", "_", "."):
        name = name.replace(ch, " ")
    return " ".join(name.lower().split())


def flavor_monthly(name: str, vcpus: int, ram_mb: int, disk_gb: int):
    """Return (monthly_price_inr, source, spec_mismatch)."""
    key = normalize_flavor(name or "")
    if key in FLAVOR_MONTHLY:
        spec = FLAVOR_SPECS[key]
        mismatch = spec != (vcpus, ram_mb, disk_gb)
        return FLAVOR_MONTHLY[key], "rate-card", mismatch
    price = (
        vcpus * ADDON_VCPU
        + (ram_mb / 1024) * ADDON_RAM_PER_GB
        + disk_gb * ADDON_DISK_PER_GB
    )
    return price, "computed", False


def period_hours(begin, end) -> float:
    return (end - begin).total_seconds() / 3600


def inr(amount: float) -> str:
    """Format with Indian digit grouping: 92,159.00 / 1,23,456.00"""
    neg = amount < 0
    whole, _, frac = f"{abs(amount):.2f}".partition(".")
    if len(whole) > 3:
        head, tail = whole[:-3], whole[-3:]
        groups = []
        while len(head) > 2:
            groups.insert(0, head[-2:])
            head = head[:-2]
        if head:
            groups.insert(0, head)
        whole = ",".join(groups + [tail])
    return f"₹{'-' if neg else ''}{whole}.{frac}"