package api

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"strconv"
	"strings"

	"gitea.dooplex.hu/admin/felhom-controller/internal/config"
	"gitea.dooplex.hu/admin/felhom-controller/internal/stacks"
	"gitea.dooplex.hu/admin/felhom-controller/internal/system"
)

// Router handles all /api/* requests.
type Router struct {
	cfg      *config.Config
	stackMgr *stacks.Manager
	logger   *log.Logger
}

func NewRouter(cfg *config.Config, stackMgr *stacks.Manager, logger *log.Logger) *Router {
	return &Router{cfg: cfg, stackMgr: stackMgr, logger: logger}
}

type apiResponse struct {
	OK      bool        `json:"ok"`
	Data    interface{} `json:"data,omitempty"`
	Error   string      `json:"error,omitempty"`
	Message string      `json:"message,omitempty"`
}

// ServeHTTP routes /api/* requests.
func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	path := strings.TrimPrefix(req.URL.Path, "/api")
	path = strings.TrimSuffix(path, "/")

	switch {
	// GET /api/stacks
	case path == "/stacks" && req.Method == http.MethodGet:
		r.listStacks(w, req)

	// POST /api/stacks/rescan — re-scan stacks directory for new/removed stacks
	case path == "/stacks/rescan" && req.Method == http.MethodPost:
		r.rescanStacks(w, req)

	// GET /api/stacks/{name}
	case strings.HasPrefix(path, "/stacks/") && req.Method == http.MethodGet && !hasSubpath(path, "/stacks/"):
		r.getStack(w, req, trimSegment(path, "/stacks/"))

	// GET /api/stacks/{name}/deploy-fields
	case hasSuffix(path, "/deploy-fields") && req.Method == http.MethodGet:
		r.getDeployFields(w, req, extractName(path, "/deploy-fields"))

	// POST /api/stacks/{name}/deploy
	case hasSuffix(path, "/deploy") && req.Method == http.MethodPost:
		r.deployStack(w, req, extractName(path, "/deploy"))

	// POST /api/stacks/{name}/start
	case hasSuffix(path, "/start") && req.Method == http.MethodPost:
		r.actionStack(w, "start", extractName(path, "/start"))

	// POST /api/stacks/{name}/stop
	case hasSuffix(path, "/stop") && req.Method == http.MethodPost:
		r.actionStack(w, "stop", extractName(path, "/stop"))

	// POST /api/stacks/{name}/restart
	case hasSuffix(path, "/restart") && req.Method == http.MethodPost:
		r.actionStack(w, "restart", extractName(path, "/restart"))

	// POST /api/stacks/{name}/update
	case hasSuffix(path, "/update") && req.Method == http.MethodPost:
		r.actionStack(w, "update", extractName(path, "/update"))

	// GET /api/stacks/{name}/logs
	case hasSuffix(path, "/logs") && req.Method == http.MethodGet:
		r.getStackLogs(w, req, extractName(path, "/logs"))

	// GET /api/system/info
	case path == "/system/info" && req.Method == http.MethodGet:
		r.systemInfo(w, req)

	default:
		writeJSON(w, http.StatusNotFound, apiResponse{OK: false, Error: "endpoint not found"})
	}
}

// HealthHandler responds to /api/health (no auth required).
func (r *Router) HealthHandler(w http.ResponseWriter, req *http.Request) {
	writeJSON(w, http.StatusOK, apiResponse{OK: true, Message: "felhom-controller is healthy"})
}

// --- Stack handlers ---

func (r *Router) listStacks(w http.ResponseWriter, _ *http.Request) {
	writeJSON(w, http.StatusOK, apiResponse{OK: true, Data: r.stackMgr.GetStacks()})
}

func (r *Router) rescanStacks(w http.ResponseWriter, _ *http.Request) {
	r.logger.Printf("[API] Manual stack rescan requested")
	if err := r.stackMgr.ScanStacks(); err != nil {
		r.logger.Printf("[API] Stack rescan failed: %v", err)
		writeJSON(w, http.StatusInternalServerError, apiResponse{OK: false, Error: err.Error()})
		return
	}
	stackCount := len(r.stackMgr.GetStacks())
	r.logger.Printf("[API] Stack rescan completed: %d stacks found", stackCount)
	writeJSON(w, http.StatusOK, apiResponse{
		OK:      true,
		Message: fmt.Sprintf("Rescan completed: %d stacks found", stackCount),
	})
}

func (r *Router) getStack(w http.ResponseWriter, _ *http.Request, name string) {
	stack, ok := r.stackMgr.GetStack(name)
	if !ok {
		writeJSON(w, http.StatusNotFound, apiResponse{OK: false, Error: "stack not found: " + name})
		return
	}
	writeJSON(w, http.StatusOK, apiResponse{OK: true, Data: stack})
}

func (r *Router) getDeployFields(w http.ResponseWriter, _ *http.Request, name string) {
	meta, appCfg, err := r.stackMgr.GetDeployFields(name)
	if err != nil {
		writeJSON(w, http.StatusNotFound, apiResponse{OK: false, Error: err.Error()})
		return
	}

	data := map[string]interface{}{
		"metadata":   meta,
		"app_config": appCfg,
		"domain":     r.cfg.Customer.Domain,
		"logo_url":   r.cfg.AppLogoURL(meta.Slug),
	}
	writeJSON(w, http.StatusOK, apiResponse{OK: true, Data: data})
}

func (r *Router) deployStack(w http.ResponseWriter, req *http.Request, name string) {
	r.logger.Printf("[API] Deploy requested for stack: %s", name)

	var body struct {
		Values map[string]string `json:"values"`
	}
	if err := json.NewDecoder(req.Body).Decode(&body); err != nil {
		writeJSON(w, http.StatusBadRequest, apiResponse{OK: false, Error: "invalid request body"})
		return
	}

	deployReq := stacks.DeployRequest{
		StackName: name,
		Values:    body.Values,
	}

	warning, err := r.stackMgr.DeployStack(deployReq)
	if err != nil {
		r.logger.Printf("[API] Deploy failed for %s: %v", name, err)
		status := http.StatusInternalServerError
		if strings.Contains(err.Error(), "already deployed") {
			status = http.StatusConflict
		}
		if strings.Contains(err.Error(), "required field") || strings.Contains(err.Error(), "does not exist") || strings.Contains(err.Error(), "kötelező") || strings.Contains(err.Error(), "memória") {
			status = http.StatusBadRequest
		}
		writeJSON(w, status, apiResponse{OK: false, Error: err.Error()})
		return
	}

	resp := apiResponse{OK: true, Message: "Stack " + name + " deployed"}
	if warning != "" {
		resp.Data = map[string]string{"warning": warning}
	}
	writeJSON(w, http.StatusOK, resp)
}

func (r *Router) actionStack(w http.ResponseWriter, action, name string) {
	r.logger.Printf("[API] %s requested for stack: %s", action, name)

	var err error
	switch action {
	case "start":
		err = r.stackMgr.StartStack(name)
	case "stop":
		err = r.stackMgr.StopStack(name)
	case "restart":
		err = r.stackMgr.RestartStack(name)
	case "update":
		err = r.stackMgr.UpdateStack(name)
	}

	if err != nil {
		status := http.StatusInternalServerError
		if strings.Contains(err.Error(), "protected") {
			status = http.StatusForbidden
		}
		if strings.Contains(err.Error(), "not found") {
			status = http.StatusNotFound
		}
		writeJSON(w, status, apiResponse{OK: false, Error: err.Error()})
		return
	}

	writeJSON(w, http.StatusOK, apiResponse{OK: true, Message: "Stack " + name + " " + action + " completed"})
}

func (r *Router) getStackLogs(w http.ResponseWriter, req *http.Request, name string) {
	lines := 100
	if v := req.URL.Query().Get("lines"); v != "" {
		if n, err := strconv.Atoi(v); err == nil && n > 0 {
			lines = n
		}
	}

	output, err := r.stackMgr.GetLogs(name, lines)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, apiResponse{OK: false, Error: err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, apiResponse{OK: true, Data: map[string]string{"logs": output}})
}

func (r *Router) systemInfo(w http.ResponseWriter, _ *http.Request) {
	info := system.GetInfo(r.cfg.Paths.HDDPath)
	writeJSON(w, http.StatusOK, apiResponse{OK: true, Data: info})
}

// --- Helpers ---

func hasSuffix(path, suffix string) bool { return strings.HasSuffix(path, suffix) }

func hasSubpath(path, prefix string) bool {
	rest := strings.TrimPrefix(path, prefix)
	return strings.Contains(rest, "/")
}

func trimSegment(path, prefix string) string {
	return strings.TrimPrefix(path, prefix)
}

func extractName(path, suffix string) string {
	s := strings.TrimPrefix(path, "/stacks/")
	return strings.TrimSuffix(s, suffix)
}

func writeJSON(w http.ResponseWriter, status int, v interface{}) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	if err := json.NewEncoder(w).Encode(v); err != nil {
		log.Printf("[ERROR] Failed to write JSON response: %v", err)
	}
}