"""Dashboard statistics building and cache key constants."""

# Cache keys used by views
CACHE_KEY_STATS = "dashboard_stats"
CACHE_KEY_AUDITS = "dashboard_audits"
CACHE_KEY_CURRENT_CLUSTER = "dashboard_current_cluster"
CACHE_KEY_SOURCE_STATUS = "dashboard_source_status"

# Empty structures for skeleton context (same shape as build_stats output)
EMPTY_FLAVORS = {
    "first_common_flavor": {"name": "—", "count": 0},
    "second_common_flavor": None,
    "third_common_flavor": None,
}


def build_stats(metrics: dict, region_name: str, flavors: dict) -> dict:
    """
    Build stats dict from raw metrics and OpenStack-derived data.
    Returns region, pcpu, vcpu, pram, vram, vm, flavors (no audits/current_cluster).
    """
    hosts_total = metrics.get("hosts_total") or 1
    pcpu_total = metrics.get("pcpu_total", 0)
    pcpu_usage = metrics.get("pcpu_usage", 0)
    vcpu_allocated = metrics.get("vcpu_allocated", 0)
    vcpu_overcommit_max = metrics.get("vcpu_overcommit_max", 0)
    pram_total = metrics.get("pram_total", 0)
    pram_usage = metrics.get("pram_usage", 0)
    vram_allocated = metrics.get("vram_allocated", 0)
    vram_overcommit_max = metrics.get("vram_overcommit_max", 0)
    vm_count = metrics.get("vm_count", 0)
    vm_active = metrics.get("vm_active", 0)

    vcpu_total = pcpu_total * vcpu_overcommit_max
    vram_total = pram_total * vram_overcommit_max

    return {
        "region": {"name": region_name, "hosts_total": hosts_total},
        "pcpu": {
            "total": pcpu_total,
            "usage": pcpu_usage,
            "free": pcpu_total - pcpu_usage,
            "used_percentage": (pcpu_usage / pcpu_total * 100) if pcpu_total else 0,
        },
        "vcpu": {
            "total": vcpu_total,
            "allocated": vcpu_allocated,
            "free": vcpu_total - vcpu_allocated,
            "allocated_percentage": (vcpu_allocated / vcpu_total * 100) if vcpu_total else 0,
            "overcommit_ratio": (vcpu_allocated / pcpu_total) if pcpu_total else 0,
            "overcommit_max": vcpu_overcommit_max,
        },
        "pram": {
            "total": pram_total,
            "usage": pram_usage,
            "free": pram_total - pram_usage,
            "used_percentage": (pram_usage / pram_total * 100) if pram_total else 0,
        },
        "vram": {
            "total": vram_total,
            "allocated": vram_allocated,
            "free": vram_total - vram_allocated,
            "allocated_percentage": (vram_allocated / vram_total * 100) if vram_total else 0,
            "overcommit_ratio": (vram_allocated / pram_total) if pram_total else 0,
            "overcommit_max": vram_overcommit_max,
        },
        "vm": {
            "count": vm_count,
            "active": vm_active,
            "stopped": vm_count - vm_active,
            "avg_cpu": vcpu_allocated / vm_count if vm_count else 0,
            "avg_ram": vram_allocated / vm_count if vm_count else 0,
            "density": vm_count / hosts_total if hosts_total else 0,
        },
        "flavors": flavors,
    }