package api

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

	"provisioning/internal/config"
	"provisioning/internal/model"
	"provisioning/internal/orchestrator"
	"provisioning/internal/pxe"
	"provisioning/internal/statemachine"
	"provisioning/internal/store"

	"github.com/go-chi/chi/v5"
)

type BootAPI struct {
	Hosts        *store.Hosts
	Images       *store.Images
	Runner       *orchestrator.Runner
	Orchestrator *orchestrator.HostOrchestrator
	Config       *config.Config
	ServerTypes  *config.ServerTypeRegistry
}

func (a *BootAPI) IPXEScript(w http.ResponseWriter, r *http.Request) {
	mac := normalizeMAC(chi.URLParam(r, "mac"))
	host, err := a.Hosts.GetByMAC(r.Context(), mac)
	if err != nil {
		if errors.Is(err, store.ErrNotFound) {
			http.Error(w, "#!ipxe\nexit", http.StatusNotFound)
			return
		}
		http.Error(w, "internal error", http.StatusInternalServerError)
		return
	}

	img, err := a.Images.GetDefault(r.Context())
	if err != nil {
		http.Error(w, "#!ipxe\necho No default image configured\nshell", http.StatusServiceUnavailable)
		return
	}

	if host.State == model.StatePXEReady {
		a.Runner.Transition(r.Context(), host.ID, statemachine.TriggerPXEScriptServed)
		a.Runner.LogActivity(r.Context(), host.ID, model.LogInfo, "pxe", "iPXE script served — kernel + initrd delivered")
	}

	w.Header().Set("Content-Type", "text/plain")
	w.Write([]byte(pxe.BuildIPXEScript(a.Config.Server.PublicURL, img, mac)))
}

func (a *BootAPI) AnswerFile(w http.ResponseWriter, r *http.Request) {
	var sysInfo struct {
		MAC string `json:"mac"`
	}
	if err := json.NewDecoder(r.Body).Decode(&sysInfo); err != nil {
		http.Error(w, "invalid json", http.StatusBadRequest)
		return
	}

	mac := normalizeMAC(sysInfo.MAC)
	host, err := a.Hosts.GetByMAC(r.Context(), mac)
	if err != nil {
		if errors.Is(err, store.ErrNotFound) {
			http.Error(w, "unknown host", http.StatusForbidden)
			return
		}
		http.Error(w, "internal error", http.StatusInternalServerError)
		return
	}

	st, ok := a.ServerTypes.Get(host.ServerType)
	if !ok {
		http.Error(w, "unknown server type", http.StatusInternalServerError)
		return
	}

	if host.State == model.StatePXEBooted {
		a.Runner.Transition(r.Context(), host.ID, statemachine.TriggerAnswerServed)
		a.Runner.LogActivity(r.Context(), host.ID, model.LogInfo, "pxe", "Answer file served — installation starting")
	}

	_, pubKey, _ := a.Hosts.GetEphemeralKey(r.Context(), host.ID)
	if pubKey == "" {
		http.Error(w, "no ephemeral key for host", http.StatusInternalServerError)
		return
	}

	answer := pxe.GenerateAnswerFile(host, st, a.Config, pubKey)
	w.Header().Set("Content-Type", "application/toml")
	w.Write([]byte(answer))
}

func (a *BootAPI) InstallComplete(w http.ResponseWriter, r *http.Request) {
	id, ok := idFromURL(w, r)
	if !ok {
		return
	}

	host, err := a.Hosts.Get(r.Context(), id)
	if err != nil {
		writeJSONErr(w, http.StatusNotFound, "host not found")
		return
	}

	if host.State == model.StateInstalling {
		a.Runner.LogActivity(r.Context(), host.ID, model.LogInfo, "pxe", "Install-complete webhook received")
		if _, err := a.Runner.Transition(r.Context(), host.ID, statemachine.TriggerInstallWebhook); err != nil {
			log.Printf("host %d: install-complete transition failed: %v", host.ID, err)
		}
	}

	w.WriteHeader(http.StatusOK)
}

func (a *BootAPI) FirstBootScript(w http.ResponseWriter, r *http.Request) {
	id, ok := idFromURL(w, r)
	if !ok {
		return
	}

	host, err := a.Hosts.Get(r.Context(), id)
	if err != nil {
		http.Error(w, "host not found", http.StatusNotFound)
		return
	}

	st, ok := a.ServerTypes.Get(host.ServerType)
	if !ok {
		http.Error(w, "unknown server type", http.StatusInternalServerError)
		return
	}

	script := pxe.GenerateFirstBootScript(host, st, a.Config)
	w.Header().Set("Content-Type", "text/x-shellscript")
	w.Write([]byte(script))
}

func (a *BootAPI) PhoneHome(w http.ResponseWriter, r *http.Request) {
	id, ok := idFromURL(w, r)
	if !ok {
		return
	}

	var req struct {
		IP         string `json:"ip"`
		HardwareID string `json:"hardware_id"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeJSONErr(w, http.StatusBadRequest, "invalid json")
		return
	}

	host, err := a.Hosts.Get(r.Context(), id)
	if err != nil {
		writeJSONErr(w, http.StatusNotFound, "host not found")
		return
	}

	log.Printf("host %d (%s): phone-home from %s, hwid=%s", host.ID, host.Hostname, req.IP, req.HardwareID)
	a.Runner.LogActivity(r.Context(), host.ID, model.LogInfo, "pxe", fmt.Sprintf("Phone-home received from %s", req.IP))
	a.Orchestrator.HandlePhoneHome(r.Context(), host.ID, req.IP, req.HardwareID)

	writeJSON(w, http.StatusOK, map[string]any{"ok": true})
}

func normalizeMAC(m string) string {
	m = strings.ToLower(strings.TrimSpace(m))
	m = strings.ReplaceAll(m, "-", ":")
	return m
}