package handlers

import (
	"context"
	"strconv"
	"strings"
	"time"

	"github.com/gin-gonic/gin"

	"git.netcell-it.de/projekte/edgeguard-native/internal/handlers/response"
	"git.netcell-it.de/projekte/edgeguard-native/internal/services/syslogs"
)

// LogsHandler exposes:
//
//	GET /api/v1/logs?sources=edgeguard-api,haproxy,...
//	                &levels=error,warn
//	                &since=2026-05-12T20:00:00Z
//	                &until=2026-05-12T21:00:00Z
//	                &grep=503
//	                &limit=500
//
// Aggregiert journalctl-Output für die EdgeGuard-Services + die
// audit_log-Tabelle in ein einheitliches Entry-Format.
type LogsHandler struct {
	Reader *syslogs.Reader
}

func NewLogsHandler(r *syslogs.Reader) *LogsHandler {
	return &LogsHandler{Reader: r}
}

func (h *LogsHandler) Register(rg *gin.RouterGroup) {
	g := rg.Group("/logs")
	g.GET("", h.List)
	g.GET("/sources", h.Sources)
}

// Sources gibt die statische Quellen-Liste fürs UI-Dropdown zurück —
// das UI muss die nicht hartcodieren.
func (h *LogsHandler) Sources(c *gin.Context) {
	out := make([]string, 0, len(syslogs.AllSources))
	for _, s := range syslogs.AllSources {
		out = append(out, string(s))
	}
	response.OK(c, gin.H{"sources": out})
}

// List baut den Filter aus den Query-Params und führt Reader.Query aus.
// Errors aus einzelnen Sources sind nicht-fatal (Reader.Query logged
// sie selbst); wir liefern was vorhanden ist.
func (h *LogsHandler) List(c *gin.Context) {
	ctx, cancel := context.WithTimeout(c.Request.Context(), 10*time.Second)
	defer cancel()

	f := syslogs.Filter{
		Grep: c.Query("grep"),
	}
	if s := c.Query("sources"); s != "" {
		for _, raw := range strings.Split(s, ",") {
			s := strings.TrimSpace(raw)
			if s != "" {
				f.Sources = append(f.Sources, syslogs.Source(s))
			}
		}
	}
	if s := c.Query("levels"); s != "" {
		for _, raw := range strings.Split(s, ",") {
			s := strings.TrimSpace(raw)
			if s != "" {
				f.Levels = append(f.Levels, syslogs.Level(s))
			}
		}
	}
	if s := c.Query("since"); s != "" {
		if t, err := time.Parse(time.RFC3339, s); err == nil {
			f.Since = t
		}
	}
	if s := c.Query("until"); s != "" {
		if t, err := time.Parse(time.RFC3339, s); err == nil {
			f.Until = t
		}
	}
	if s := c.Query("limit"); s != "" {
		if n, err := strconv.Atoi(s); err == nil {
			f.Limit = n
		}
	}
	entries, _ := h.Reader.Query(ctx, f)
	response.OK(c, gin.H{"entries": entries, "count": len(entries)})
}