package config

import (
	"fmt"
	"os"
	"strconv"
)

// RoutingConfig holds the runtime configuration for the routing pod.
// Separate from Config because the routing pod's surface differs from the supervisor's.
type RoutingConfig struct {
	Port               string  // ROUTING_PORT, default 3210
	MCPAuthToken       string  // ROUTING_MCP_TOKEN, optional bearer token
	LiteLLMBaseURL     string  // LITELLM_BASE_URL, default http://piguard:4000
	LiteLLMAPIKey      string  // LITELLM_API_KEY
	BrainURL           string  // BRAIN_URL, default http://ingestion.supervisor:3300
	FastModel          string  // HYPERGUILD_FAST_MODEL, default koala/qwen35-9b-fast
	ThinkingModel      string  // HYPERGUILD_THINKING_MODEL, default iguana/gemma4-26b
	// RouteLocalFloor and RouteLocalCeil intentionally invert the usual
	// floor < ceil mathematical convention: Floor (default 0.90) is the
	// UPPER boundary — at/above it, always route local; Ceil (default 0.70)
	// is the LOWER boundary — below it, always route Claude. The band in
	// between is the 50/50 sample zone. The naming follows the spec's policy
	// vocabulary; see internal/routing/policy.go for the consumer.
	RouteLocalFloor    float64 // HYPERGUILD_ROUTE_LOCAL_FLOOR, default 0.90
	RouteLocalCeil     float64 // HYPERGUILD_ROUTE_LOCAL_CEIL, default 0.70
	PassRateTTLSeconds int     // HYPERGUILD_PASS_RATE_TTL_SECONDS, default 60
}

func LoadRouting() (RoutingConfig, error) {
	cfg := RoutingConfig{
		Port:           envOr("ROUTING_PORT", "3210"),
		MCPAuthToken:   os.Getenv("ROUTING_MCP_TOKEN"),
		LiteLLMBaseURL: envOr("LITELLM_BASE_URL", "http://piguard:4000"),
		LiteLLMAPIKey:  os.Getenv("LITELLM_API_KEY"),
		BrainURL:       envOr("BRAIN_URL", "http://ingestion.supervisor:3300"),
		FastModel:      envOr("HYPERGUILD_FAST_MODEL", "koala/qwen35-9b-fast"),
		ThinkingModel:  envOr("HYPERGUILD_THINKING_MODEL", "iguana/gemma4-26b"),
	}

	floor, err := parseFloatEnv("HYPERGUILD_ROUTE_LOCAL_FLOOR", 0.90)
	if err != nil {
		return RoutingConfig{}, err
	}
	cfg.RouteLocalFloor = floor

	ceil, err := parseFloatEnv("HYPERGUILD_ROUTE_LOCAL_CEIL", 0.70)
	if err != nil {
		return RoutingConfig{}, err
	}
	cfg.RouteLocalCeil = ceil

	ttl, err := parseIntEnv("HYPERGUILD_PASS_RATE_TTL_SECONDS", 60)
	if err != nil {
		return RoutingConfig{}, err
	}
	cfg.PassRateTTLSeconds = ttl

	return cfg, nil
}

func parseFloatEnv(key string, def float64) (float64, error) {
	v := os.Getenv(key)
	if v == "" {
		return def, nil
	}
	f, err := strconv.ParseFloat(v, 64)
	if err != nil {
		return 0, fmt.Errorf("config: %s: %w", key, err)
	}
	return f, nil
}

func parseIntEnv(key string, def int) (int, error) {
	v := os.Getenv(key)
	if v == "" {
		return def, nil
	}
	n, err := strconv.Atoi(v)
	if err != nil {
		return 0, fmt.Errorf("config: %s: %w", key, err)
	}
	return n, nil
}