package nodedispatch

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"strings"

	"evobgp/internal/store"
)

// AgentHealthResult is the parsed outcome of GET /v1/agent/health on a replica.
type AgentHealthResult struct {
	OK                    bool
	Error                 string
	LastAppliedRevisionID string
	LastSyncAt            string
}

// FetchAgentHealth GETs /v1/agent/health for UI Connected/Offline status.
func FetchAgentHealth(ctx context.Context, sp *store.Speaker, opts Options) AgentHealthResult {
	if sp == nil {
		return AgentHealthResult{Error: "nil speaker"}
	}
	meta := store.ParseSpeakerMeta(sp.MetaJSON)
	url := store.AgentHealthURL(meta)
	if url == "" {
		return AgentHealthResult{Error: "agent_domain not configured"}
	}
	secret := strings.TrimSpace(meta.AgentSecret)
	if secret == "" {
		return AgentHealthResult{Error: "agent_secret missing"}
	}
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
	if err != nil {
		return AgentHealthResult{Error: err.Error()}
	}
	req.Header.Set("Authorization", "Bearer "+secret)
	resp, err := opts.client().Do(req)
	if err != nil {
		return AgentHealthResult{Error: err.Error()}
	}
	defer func() { _ = resp.Body.Close() }()
	b, _ := io.ReadAll(resp.Body)
	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		return AgentHealthResult{
			Error: fmt.Sprintf("HTTP %d: %s", resp.StatusCode, strings.TrimSpace(string(b))),
		}
	}
	var out struct {
		OK                    bool   `json:"ok"`
		LastAppliedRevisionID string `json:"last_applied_revision_id"`
		LastSyncAt            string `json:"last_sync_at"`
	}
	if err := json.Unmarshal(b, &out); err != nil {
		return AgentHealthResult{Error: err.Error()}
	}
	res := AgentHealthResult{
		OK:                    out.OK,
		LastAppliedRevisionID: strings.TrimSpace(out.LastAppliedRevisionID),
		LastSyncAt:            strings.TrimSpace(out.LastSyncAt),
	}
	if !res.OK {
		res.Error = "agent reported ok=false"
	}
	return res
}