package api

import (
	"encoding/json"
	"net/http"
	"strings"

	"crypto-miner-server/internal/clearance"
	"crypto-miner-server/internal/db"
	"crypto-miner-server/internal/strategy"
)

type fleetGraftRequest struct {
	SourceAgentID string `json:"source_agent_id"`
	TargetAgentID string `json:"target_agent_id"`
}

// PostFleetGraft splices a winning strain from source onto target without re-spreading target.
func (f *FleetHandler) PostFleetGraft(w http.ResponseWriter, r *http.Request) {
	if f.db == nil || f.ws == nil {
		http.Error(w, "fleet services unavailable", http.StatusServiceUnavailable)
		return
	}
	policy := f.ws.ServerPolicy()
	if !strategy.GraftEnabled(policy.AIControlEnabled, policy.FleetRolesEnabled) {
		http.Error(w, "graft requires ai_control_enabled and fleet_roles_enabled", http.StatusBadRequest)
		return
	}
	var req fleetGraftRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "invalid body", http.StatusBadRequest)
		return
	}
	sourceID := strings.TrimSpace(req.SourceAgentID)
	targetID := strings.TrimSpace(req.TargetAgentID)
	if sourceID == "" || targetID == "" {
		http.Error(w, "source_agent_id and target_agent_id are required", http.StatusBadRequest)
		return
	}
	if sourceID == targetID {
		http.Error(w, "source and target must differ", http.StatusBadRequest)
		return
	}

	level := clearance.L0
	if mgr := f.ws.ClearanceManager(); mgr != nil {
		level = mgr.Level(targetID)
	}
	if level < clearance.L4 {
		writeJSON(w, map[string]interface{}{
			"success": false,
			"error":   "target clearance insufficient for spread_graft (requires L4)",
		})
		return
	}

	graftPolicy, err := f.ws.ApproveFleetGraft(sourceID, targetID)
	if err != nil {
		_ = (&OathLedgerBridge{DB: f.db, Hub: f.ws}).Record(
			AuthUsername(r), db.OathGraft, targetID, "", db.OathOutcomeFail,
			map[string]string{"source_agent_id": sourceID, "target_agent_id": targetID},
			map[string]interface{}{"error": err.Error()},
		)
		writeJSON(w, map[string]interface{}{
			"success": false,
			"error":   err.Error(),
		})
		return
	}

	writeJSON(w, map[string]interface{}{
		"success":      true,
		"source_id":    sourceID,
		"target_id":    targetID,
		"graft_policy": graftPolicy,
		"pushed":       f.ws.IsAgentReachable(targetID),
	})
	_ = f.db.InsertAudit(AuthUsername(r), "spread_graft", targetID, map[string]interface{}{
		"source_agent_id": sourceID,
		"graft_tier":      graftPolicy.GraftTier,
		"strain":          graftPolicy.GraftSourceStrain,
	})
	_ = (&OathLedgerBridge{DB: f.db, Hub: f.ws}).Record(
		AuthUsername(r), db.OathGraft, targetID, graftPolicy.GraftSourceStrain, db.OathOutcomeSuccess,
		map[string]interface{}{
			"source_agent_id": sourceID,
			"graft_tier":      graftPolicy.GraftTier,
			"graft_policy":    graftPolicy,
		},
		map[string]interface{}{
			"source_agent_id": sourceID,
			"graft_tier":      graftPolicy.GraftTier,
			"pushed":          f.ws.IsAgentReachable(targetID),
		},
	)
}