// Package gateway provides the initial sync logic that fetches agent and
// session data from the OpenClaw gateway via WS RPCs after handshake,
// persists to the repository, merges session state into agent cards, and
// broadcasts the merged fleet to SSE clients.
package gateway

import (
	"context"
	"encoding/json"
	"fmt"
	"time"

	"code.cubecraftcreations.com/CubeCraft-Creations/Control-Center/go-backend/internal/models"
)

// ── RPC response types ───────────────────────────────────────────────────

// agentListItem represents a single agent returned by the agents.list RPC.
type agentListItem struct {
	ID       string          `json:"id"`
	Name     string          `json:"name"`
	Model    string          `json:"model"`
	Role     string          `json:"role"`
	Channel  string          `json:"channel"`
	Metadata json.RawMessage `json:"metadata"`
}

// sessionListItem represents a single session returned by the sessions.list RPC.
type sessionListItem struct {
	SessionKey     string `json:"sessionKey"`
	AgentID        string `json:"agentId"`
	Status         string `json:"status"` // running, done, streaming, error
	TotalTokens    int    `json:"totalTokens"`
	LastActivityAt string `json:"lastActivityAt"`
}

// ── Sync logic ──────────────────────────────────────────────────────────

// initialSync fetches agents and sessions from the gateway via WS RPCs,
// persists them, merges session state into agent cards, and broadcasts
// the merged fleet as a fleet.update event.
func (c *WSClient) initialSync(ctx context.Context) error {
	c.logger.Info("initial sync starting")

	// 1. Fetch agents via RPC
	agentsRaw, err := c.Send("agents.list", nil)
	if err != nil {
		return fmt.Errorf("agents.list RPC: %w", err)
	}

	var agentItems []agentListItem
	if err := json.Unmarshal(agentsRaw, &agentItems); err != nil {
		return fmt.Errorf("parse agents.list response: %w", err)
	}

	c.logger.Info("agents.list received", "count", len(agentItems))

	// 2. Persist each agent (create if not exists, update if changed)
	for _, item := range agentItems {
		card := agentItemToCard(item)

		existing, err := c.agents.Get(ctx, card.ID)
		if err != nil {
			// Agent doesn't exist — create it
			if createErr := c.agents.Create(ctx, card); createErr != nil {
				c.logger.Warn("sync: agent create failed", "id", card.ID, "error", createErr)
				continue
			}
			c.logger.Info("sync: agent created", "id", card.ID)
			continue
		}

		// Agent exists — update display name or role if changed
		if existing.DisplayName != card.DisplayName || existing.Role != card.Role {
			// Update what we can via UpdateAgentRequest
			channel := card.Channel
			_, updateErr := c.agents.Update(ctx, card.ID, models.UpdateAgentRequest{
				Channel: &channel,
			})
			if updateErr != nil {
				c.logger.Warn("sync: agent update failed", "id", card.ID, "error", updateErr)
			}
		}
	}

	// 3. Fetch sessions via RPC
	sessionsRaw, err := c.Send("sessions.list", nil)
	if err != nil {
		return fmt.Errorf("sessions.list RPC: %w", err)
	}

	var sessionItems []sessionListItem
	if err := json.Unmarshal(sessionsRaw, &sessionItems); err != nil {
		return fmt.Errorf("parse sessions.list response: %w", err)
	}

	c.logger.Info("sessions.list received", "count", len(sessionItems))

	// 4. Build agentId → session map for merge
	sessionByAgent := make(map[string]sessionListItem)
	for _, s := range sessionItems {
		if s.AgentID != "" {
			sessionByAgent[s.AgentID] = s
		}
	}

	// 5. Merge session state into agents, update DB, and collect for broadcast
	mergedAgents := make([]models.AgentCardData, 0, len(agentItems))

	for _, item := range agentItems {
		card := agentItemToCard(item)

		if session, ok := sessionByAgent[item.ID]; ok {
			// Merge session state into agent card
			card.SessionKey = session.SessionKey
			card.Status = mapSessionStatus(session.Status)
			card.LastActivity = session.LastActivityAt

			if session.TotalTokens > 0 {
				prog := min(session.TotalTokens/100, 100)
				card.TaskProgress = &prog
			}
		}

		// Persist merged status change
		existing, err := c.agents.Get(ctx, card.ID)
		if err == nil && existing.Status != card.Status {
			status := card.Status
			_, updateErr := c.agents.Update(ctx, card.ID, models.UpdateAgentRequest{
				Status: &status,
			})
			if updateErr != nil {
				c.logger.Warn("sync: agent status update failed", "id", card.ID, "error", updateErr)
			}
		}

		mergedAgents = append(mergedAgents, card)
	}

	// 6. Broadcast the full merged fleet
	c.broker.Broadcast("fleet.update", mergedAgents)
	c.logger.Info("initial sync complete", "agents", len(mergedAgents))

	return nil
}

// mapSessionStatus converts a gateway session status string to an AgentStatus.
//   - "running" / "streaming" → active
//   - "error"                 → error
//   - "done" / "" / other     → idle
func mapSessionStatus(status string) models.AgentStatus {
	switch status {
	case "running", "streaming":
		return models.AgentStatusActive
	case "error":
		return models.AgentStatusError
	default:
		return models.AgentStatusIdle
	}
}

// agentItemToCard converts an agentListItem from the gateway RPC into an
// AgentCardData suitable for persistence and broadcasting.
func agentItemToCard(item agentListItem) models.AgentCardData {
	role := item.Role
	if role == "" {
		role = "agent"
	}
	channel := item.Channel
	if channel == "" {
		channel = "discord"
	}
	name := item.Name
	if name == "" {
		name = item.ID
	}

	return models.AgentCardData{
		ID:          item.ID,
		DisplayName: name,
		Role:        role,
		Status:      models.AgentStatusIdle, // default; overridden by session merge
		SessionKey:  "",
		Channel:     channel,
		LastActivity: time.Now().UTC().Format(time.RFC3339),
	}
}