package webui

import (
	"encoding/json"
	"errors"
	"net/http"
	"os"
	"path/filepath"
	"strings"

	"bee/audit/internal/app"
	"bee/audit/internal/platform"
)

func (h *handler) handleAPIServicesList(w http.ResponseWriter, r *http.Request) {
	if h.opts.App == nil {
		writeError(w, http.StatusServiceUnavailable, "app not configured")
		return
	}
	names, err := h.opts.App.ListBeeServices()
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	type serviceInfo struct {
		Name  string `json:"name"`
		State string `json:"state"`
		Body  string `json:"body"`
	}
	result := make([]serviceInfo, 0, len(names))
	for _, name := range names {
		state := h.opts.App.ServiceState(name)
		body, _ := h.opts.App.ServiceStatus(name)
		result = append(result, serviceInfo{Name: name, State: state, Body: body})
	}
	writeJSON(w, result)
}

func (h *handler) handleAPIServicesAction(w http.ResponseWriter, r *http.Request) {
	if h.opts.App == nil {
		writeError(w, http.StatusServiceUnavailable, "app not configured")
		return
	}
	var req struct {
		Name   string `json:"name"`
		Action string `json:"action"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}
	var action platform.ServiceAction
	switch req.Action {
	case "start":
		action = platform.ServiceStart
	case "stop":
		action = platform.ServiceStop
	case "restart":
		action = platform.ServiceRestart
	default:
		writeError(w, http.StatusBadRequest, "action must be start|stop|restart")
		return
	}
	result, err := h.opts.App.ServiceActionResult(req.Name, action)
	status := "ok"
	if err != nil {
		status = "error"
	}
	// Always return 200 with output so the frontend can display the actual
	// systemctl error message instead of a generic "exit status 1".
	writeJSON(w, map[string]string{"status": status, "output": result.Body})
}

// ── Network ───────────────────────────────────────────────────────────────────

func (h *handler) handleAPINetworkStatus(w http.ResponseWriter, r *http.Request) {
	if h.opts.App == nil {
		writeError(w, http.StatusServiceUnavailable, "app not configured")
		return
	}
	ifaces, err := h.opts.App.ListInterfaces()
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, map[string]any{
		"interfaces":     ifaces,
		"default_route":  h.opts.App.DefaultRoute(),
		"pending_change": h.hasPendingNetworkChange(),
		"rollback_in":    h.pendingNetworkRollbackIn(),
	})
}

func (h *handler) handleAPINetworkDHCP(w http.ResponseWriter, r *http.Request) {
	if h.opts.App == nil {
		writeError(w, http.StatusServiceUnavailable, "app not configured")
		return
	}
	var req struct {
		Interface string `json:"interface"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}

	result, err := h.applyPendingNetworkChange(func() (app.ActionResult, error) {
		if req.Interface == "" || req.Interface == "all" {
			return h.opts.App.DHCPAllResult()
		}
		return h.opts.App.DHCPOneResult(req.Interface)
	})
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, map[string]any{
		"status":      "ok",
		"output":      result.Body,
		"rollback_in": int(netRollbackTimeout.Seconds()),
	})
}

func (h *handler) handleAPINetworkStatic(w http.ResponseWriter, r *http.Request) {
	if h.opts.App == nil {
		writeError(w, http.StatusServiceUnavailable, "app not configured")
		return
	}
	var req struct {
		Interface string   `json:"interface"`
		Address   string   `json:"address"`
		Prefix    string   `json:"prefix"`
		Gateway   string   `json:"gateway"`
		DNS       []string `json:"dns"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}
	cfg := platform.StaticIPv4Config{
		Interface: req.Interface,
		Address:   req.Address,
		Prefix:    req.Prefix,
		Gateway:   req.Gateway,
		DNS:       req.DNS,
	}
	result, err := h.applyPendingNetworkChange(func() (app.ActionResult, error) {
		return h.opts.App.SetStaticIPv4Result(cfg)
	})
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, map[string]any{
		"status":      "ok",
		"output":      result.Body,
		"rollback_in": int(netRollbackTimeout.Seconds()),
	})
}

// ── Export ────────────────────────────────────────────────────────────────────

func (h *handler) handleAPIExportList(w http.ResponseWriter, r *http.Request) {
	entries, err := listExportFiles(h.opts.ExportDir)
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, entries)
}

func (h *handler) handleAPIExportUSBTargets(w http.ResponseWriter, _ *http.Request) {
	writeAPIListResponse(w, h.opts.App != nil, func() ([]platform.RemovableTarget, error) {
		return h.opts.App.ListRemovableTargets()
	})
}

func (h *handler) handleAPIBlackboxStatus(w http.ResponseWriter, _ *http.Request) {
	state, err := app.ReadBlackboxState(filepath.Join(h.opts.ExportDir, "blackbox-state.json"))
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			writeJSON(w, app.BlackboxState{Status: "disabled", Targets: []app.BlackboxTargetStatus{}})
			return
		}
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	if state.Targets == nil {
		state.Targets = []app.BlackboxTargetStatus{}
	}
	writeJSON(w, state)
}

func (h *handler) handleAPIBlackboxEnable(w http.ResponseWriter, r *http.Request) {
	if h.opts.App == nil {
		writeError(w, http.StatusServiceUnavailable, "app not configured")
		return
	}
	var target platform.RemovableTarget
	if err := json.NewDecoder(r.Body).Decode(&target); err != nil || strings.TrimSpace(target.Device) == "" {
		writeError(w, http.StatusBadRequest, "device is required")
		return
	}
	targets, err := h.opts.App.ListRemovableTargets()
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	allowed := false
	for _, candidate := range targets {
		if candidate.Device == target.Device {
			target = candidate
			allowed = true
			break
		}
	}
	if !allowed {
		writeError(w, http.StatusBadRequest, "device not in removable target list")
		return
	}
	marker, err := app.EnableBlackboxTarget(target)
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, map[string]any{
		"status":        "ok",
		"message":       "Black-box marker written.",
		"enrollment_id": marker.EnrollmentID,
	})
}

func (h *handler) handleAPIBlackboxDisable(w http.ResponseWriter, r *http.Request) {
	var req struct {
		Device       string `json:"device"`
		EnrollmentID string `json:"enrollment_id"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}
	if err := app.DisableBlackboxTarget(req.Device, req.EnrollmentID); err != nil {
		if errors.Is(err, os.ErrNotExist) {
			writeError(w, http.StatusNotFound, "black-box target not found")
			return
		}
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, map[string]string{"status": "ok", "message": "Black-box marker removed."})
}

// ── GPU presence ──────────────────────────────────────────────────────────────