package api

import (
	"encoding/json"
	"fmt"
	"net/http"
	"strconv"
	"time"

	"github.com/bams/backend/internal/services"
	"github.com/gorilla/mux"
)

func handleHealth() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		jsonResponse(w, http.StatusOK, map[string]interface{}{
			"status":    "ok",
			"timestamp": time.Now().Unix(),
		})
	}
}

func handleDashboard(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		// Get dashboard data from all services
		dashboard := map[string]interface{}{
			"disk": map[string]interface{}{
				"total_capacity": 0,
				"used_capacity":  0,
				"repositories":   0,
			},
			"tape": map[string]interface{}{
				"library_status": "unknown",
				"drives_active":  0,
				"total_slots":    0,
				"loaded_tapes":   0,
			},
			"iscsi": map[string]interface{}{
				"targets":  0,
				"sessions": 0,
			},
			"bacula": map[string]interface{}{
				"status": "unknown",
			},
			"alerts": []map[string]interface{}{},
		}

		// Populate from services
		repos, _ := sm.Disk.ListRepositories()
		if repos != nil {
			dashboard["disk"].(map[string]interface{})["repositories"] = len(repos)
		}

		library, _ := sm.Tape.GetLibrary()
		if library != nil {
			dashboard["tape"].(map[string]interface{})["library_status"] = library.Status
			dashboard["tape"].(map[string]interface{})["drives_active"] = library.ActiveDrives
			dashboard["tape"].(map[string]interface{})["total_slots"] = library.TotalSlots
		}

		targets, _ := sm.ISCSI.ListTargets()
		if targets != nil {
			dashboard["iscsi"].(map[string]interface{})["targets"] = len(targets)
		}

		sessions, _ := sm.ISCSI.ListSessions()
		if sessions != nil {
			dashboard["iscsi"].(map[string]interface{})["sessions"] = len(sessions)
		}

		baculaStatus, _ := sm.Bacula.GetStatus()
		if baculaStatus != nil {
			dashboard["bacula"].(map[string]interface{})["status"] = baculaStatus.Status
		}

		jsonResponse(w, http.StatusOK, dashboard)
	}
}

// Disk repository handlers
func handleListRepositories(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		repos, err := sm.Disk.ListRepositories()
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, repos)
	}
}

func handleCreateRepository(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req struct {
			Name     string `json:"name"`
			Size     string `json:"size"`
			Type     string `json:"type"` // "lvm" or "zfs"
			VGName   string `json:"vg_name,omitempty"`
			PoolName string `json:"pool_name,omitempty"`
		}
		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
			jsonError(w, http.StatusBadRequest, "Invalid request body")
			return
		}

		// Validate input
		if err := validateRepositoryName(req.Name); err != nil {
			jsonError(w, http.StatusBadRequest, err.Error())
			return
		}
		if err := validateSize(req.Size); err != nil {
			jsonError(w, http.StatusBadRequest, err.Error())
			return
		}
		if req.Type != "lvm" && req.Type != "zfs" {
			jsonError(w, http.StatusBadRequest, "type must be 'lvm' or 'zfs'")
			return
		}
		if req.Type == "lvm" && req.VGName == "" {
			jsonError(w, http.StatusBadRequest, "vg_name is required for LVM repositories")
			return
		}
		if req.Type == "zfs" && req.PoolName == "" {
			jsonError(w, http.StatusBadRequest, "pool_name is required for ZFS repositories")
			return
		}

		repo, err := sm.Disk.CreateRepository(req.Name, req.Size, req.Type, req.VGName, req.PoolName)
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusCreated, repo)
	}
}

func handleGetRepository(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		repo, err := sm.Disk.GetRepository(vars["id"])
		if err != nil {
			jsonError(w, http.StatusNotFound, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, repo)
	}
}

func handleDeleteRepository(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		if err := sm.Disk.DeleteRepository(vars["id"]); err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusNoContent, nil)
	}
}

// Tape library handlers
func handleGetLibrary(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		library, err := sm.Tape.GetLibrary()
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, library)
	}
}

func handleInventory(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if err := sm.Tape.RunInventory(); err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, map[string]string{"status": "inventory_started"})
	}
}

func handleListDrives(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		drives, err := sm.Tape.ListDrives()
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, drives)
	}
}

func handleLoadTape(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		var req struct {
			Slot int `json:"slot"`
		}
		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
			jsonError(w, http.StatusBadRequest, "Invalid request body")
			return
		}

		if err := sm.Tape.LoadTape(vars["id"], req.Slot); err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, map[string]string{"status": "load_started"})
	}
}

func handleUnloadTape(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		var req struct {
			Slot int `json:"slot"`
		}
		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
			jsonError(w, http.StatusBadRequest, "Invalid request body")
			return
		}

		if err := sm.Tape.UnloadTape(vars["id"], req.Slot); err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, map[string]string{"status": "unload_started"})
	}
}

func handleListSlots(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		slots, err := sm.Tape.ListSlots()
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, slots)
	}
}

// iSCSI target handlers
func handleListTargets(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		targets, err := sm.ISCSI.ListTargets()
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, targets)
	}
}

func handleCreateTarget(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req struct {
			IQN        string   `json:"iqn"`
			Portals    []string `json:"portals"`
			Initiators []string `json:"initiators"`
		}
		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
			jsonError(w, http.StatusBadRequest, "Invalid request body")
			return
		}

		// Validate input
		if err := validateIQN(req.IQN); err != nil {
			jsonError(w, http.StatusBadRequest, err.Error())
			return
		}
		if len(req.Portals) == 0 {
			jsonError(w, http.StatusBadRequest, "at least one portal is required")
			return
		}
		for _, portal := range req.Portals {
			if err := validatePortal(portal); err != nil {
				jsonError(w, http.StatusBadRequest, err.Error())
				return
			}
		}

		target, err := sm.ISCSI.CreateTarget(req.IQN, req.Portals, req.Initiators)
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusCreated, target)
	}
}

func handleGetTarget(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		target, err := sm.ISCSI.GetTarget(vars["id"])
		if err != nil {
			jsonError(w, http.StatusNotFound, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, target)
	}
}

func handleUpdateTarget(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		var req struct {
			Portals    []string `json:"portals"`
			Initiators []string `json:"initiators"`
		}
		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
			jsonError(w, http.StatusBadRequest, "Invalid request body")
			return
		}

		target, err := sm.ISCSI.UpdateTarget(vars["id"], req.Portals, req.Initiators)
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, target)
	}
}

func handleDeleteTarget(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		if err := sm.ISCSI.DeleteTarget(vars["id"]); err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusNoContent, nil)
	}
}

func handleApplyTarget(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		if err := sm.ISCSI.ApplyTarget(vars["id"]); err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, map[string]string{"status": "applied"})
	}
}

func handleListSessions(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		sessions, err := sm.ISCSI.ListSessions()
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, sessions)
	}
}

func handleAddLUN(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		var req struct {
			LUNNumber  int    `json:"lun_number"`
			DevicePath string `json:"device_path"`
			Type       string `json:"type"` // "disk" or "tape"
		}
		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
			jsonError(w, http.StatusBadRequest, "Invalid request body")
			return
		}

		if req.Type != "disk" && req.Type != "tape" {
			jsonError(w, http.StatusBadRequest, "type must be 'disk' or 'tape'")
			return
		}

		if err := sm.ISCSI.AddLUN(vars["id"], req.LUNNumber, req.DevicePath, req.Type); err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}

		// Return updated target
		target, err := sm.ISCSI.GetTarget(vars["id"])
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, target)
	}
}

func handleRemoveLUN(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		lunNumber := 0
		if _, err := fmt.Sscanf(vars["lun"], "%d", &lunNumber); err != nil {
			jsonError(w, http.StatusBadRequest, "invalid LUN number")
			return
		}

		if err := sm.ISCSI.RemoveLUN(vars["id"], lunNumber); err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}

		// Return updated target
		target, err := sm.ISCSI.GetTarget(vars["id"])
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, target)
	}
}

// Bacula handlers
func handleBaculaStatus(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		status, err := sm.Bacula.GetStatus()
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, status)
	}
}

func handleGetBaculaConfig(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		config, err := sm.Bacula.GetConfig()
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, config)
	}
}

func handleGenerateBaculaConfig(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		config, err := sm.Bacula.GenerateConfig()
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, config)
	}
}

func handleBaculaInventory(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if err := sm.Bacula.RunInventory(); err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, map[string]string{"status": "inventory_started"})
	}
}

func handleBaculaRestart(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if err := sm.Bacula.Restart(); err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, map[string]string{"status": "restart_started"})
	}
}

// Logs and diagnostics handlers
func handleGetLogs(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		lines := 100
		if linesStr := r.URL.Query().Get("lines"); linesStr != "" {
			if n, err := strconv.Atoi(linesStr); err == nil {
				lines = n
			}
		}
		logs, err := sm.Logs.GetLogs(vars["service"], lines)
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		jsonResponse(w, http.StatusOK, logs)
	}
}

func handleStreamLogs(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		// WebSocket streaming would be implemented here
		jsonError(w, http.StatusNotImplemented, "WebSocket streaming not yet implemented")
	}
}

func handleDownloadBundle(sm *services.ServiceManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		bundle, err := sm.Logs.GenerateSupportBundle()
		if err != nil {
			jsonError(w, http.StatusInternalServerError, err.Error())
			return
		}
		w.Header().Set("Content-Type", "application/zip")
		w.Header().Set("Content-Disposition", "attachment; filename=bams-support-bundle.zip")
		w.Write(bundle)
	}
}

// Helper functions
func jsonResponse(w http.ResponseWriter, status int, data interface{}) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	if data != nil {
		json.NewEncoder(w).Encode(data)
	}
}

func jsonError(w http.ResponseWriter, status int, message string) {
	jsonResponse(w, status, map[string]string{"error": message})
}