// Package triggerapi haengt INT-20 (Trigger-/Automatisierungssystem) ein:
// Verwaltung unter /triggers. Nutzt ausschliesslich internal/trigger, keine
// eigene Fachlogik. Wie alle nicht dokument-gebundenen Routen (siehe
// internal/autoruleapi) verlangt sie eine Identitaet (moduleauth) und die
// Rechte dms.trigger.read/dms.trigger.write ueber die zentrale
// Policy-Pruefung (x-permission in openapi.json); es gibt keine
// Eigentuemerpruefung, weil Trigger nicht an ein Dokument gebunden sind.
package triggerapi

import (
	"encoding/json"
	"errors"
	"io"
	"net/http"

	"github.com/jackc/pgx/v5/pgxpool"

	"gitea.perlbach24.de/scripte/nexarch/dms/internal/authz"
	"gitea.perlbach24.de/scripte/nexarch/dms/internal/trigger"
)

type Server struct {
	pool       *pgxpool.Pool
	vault      trigger.Vault
	tenantSlug string
}

func NewServer(pool *pgxpool.Pool, vault trigger.Vault, tenantSlug string) *Server {
	return &Server{pool: pool, vault: vault, tenantSlug: tenantSlug}
}

func (s *Server) RegisterRoutes(mux *http.ServeMux) {
	mux.HandleFunc("POST /triggers", s.handleCreate)
	mux.HandleFunc("GET /triggers", s.handleList)
	mux.HandleFunc("GET /triggers/{id}", s.handleGet)
	mux.HandleFunc("DELETE /triggers/{id}", s.handleDelete)
	mux.HandleFunc("POST /triggers/{id}/enable", s.handleSetEnabled(true))
	mux.HandleFunc("POST /triggers/{id}/disable", s.handleSetEnabled(false))
}

func writeError(w http.ResponseWriter, status int, code, message string) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	_ = json.NewEncoder(w).Encode(map[string]any{"error": map[string]string{"code": code, "message": message}})
}

func caller(r *http.Request) string {
	c, _ := authz.Identity(r)
	return c
}

type dto struct {
	ID                   string  `json:"id"`
	Name                 string  `json:"name"`
	Event                string  `json:"event"`
	FilenamePattern      *string `json:"filename_pattern,omitempty"`
	DocumentTypeID       *string `json:"document_type_id,omitempty"`
	ActionType           string  `json:"action_type"`
	ActionTagID          *string `json:"action_tag_id,omitempty"`
	ActionDocumentTypeID *string `json:"action_document_type_id,omitempty"`
	WebhookURL           *string `json:"webhook_url,omitempty"`
	Enabled              bool    `json:"enabled"`
	CreatedBy            string  `json:"created_by"`
}

func toDTO(t trigger.Trigger) dto {
	return dto{ID: t.ID, Name: t.Name, Event: t.Event, FilenamePattern: t.FilenamePattern, DocumentTypeID: t.DocumentTypeID,
		ActionType: t.ActionType, ActionTagID: t.ActionTagID, ActionDocumentTypeID: t.ActionDocumentTypeID,
		WebhookURL: t.WebhookURL, Enabled: t.Enabled, CreatedBy: t.CreatedBy}
}

type createRequest struct {
	Name                 string  `json:"name"`
	Event                string  `json:"event"`
	FilenamePattern      *string `json:"filename_pattern"`
	DocumentTypeID       *string `json:"document_type_id"`
	ActionType           string  `json:"action_type"`
	ActionTagID          *string `json:"action_tag_id"`
	ActionDocumentTypeID *string `json:"action_document_type_id"`
	WebhookURL           *string `json:"webhook_url"`
	WebhookSecret        string  `json:"webhook_secret"`
}

func (s *Server) handleCreate(w http.ResponseWriter, r *http.Request) {
	c := caller(r)
	if c == "" {
		writeError(w, http.StatusBadRequest, "invalid_request", "fehlende identitaet")
		return
	}
	var req createRequest
	if err := json.NewDecoder(io.LimitReader(r.Body, 8192)).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid_request", "ungueltiger anfragekoerper")
		return
	}
	t := trigger.Trigger{
		Name: req.Name, Event: req.Event, FilenamePattern: req.FilenamePattern, DocumentTypeID: req.DocumentTypeID,
		ActionType: req.ActionType, ActionTagID: req.ActionTagID, ActionDocumentTypeID: req.ActionDocumentTypeID,
		WebhookURL: req.WebhookURL,
	}
	out, err := trigger.Create(r.Context(), s.pool, s.vault, s.tenantSlug, c, t, req.WebhookSecret)
	if errors.Is(err, trigger.ErrInvalid) {
		writeError(w, http.StatusBadRequest, "invalid_request", err.Error())
		return
	}
	if err != nil {
		writeError(w, http.StatusInternalServerError, "internal_error", err.Error())
		return
	}
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusCreated)
	_ = json.NewEncoder(w).Encode(toDTO(out))
}

func (s *Server) handleList(w http.ResponseWriter, r *http.Request) {
	list, err := trigger.List(r.Context(), s.pool)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "internal_error", err.Error())
		return
	}
	out := make([]dto, 0, len(list))
	for _, t := range list {
		out = append(out, toDTO(t))
	}
	w.Header().Set("Content-Type", "application/json")
	_ = json.NewEncoder(w).Encode(out)
}

func (s *Server) handleGet(w http.ResponseWriter, r *http.Request) {
	t, err := trigger.Get(r.Context(), s.pool, r.PathValue("id"))
	if errors.Is(err, trigger.ErrNotFound) {
		writeError(w, http.StatusNotFound, "not_found", "trigger nicht gefunden")
		return
	}
	if err != nil {
		writeError(w, http.StatusInternalServerError, "internal_error", err.Error())
		return
	}
	w.Header().Set("Content-Type", "application/json")
	_ = json.NewEncoder(w).Encode(toDTO(t))
}

func (s *Server) handleDelete(w http.ResponseWriter, r *http.Request) {
	c := caller(r)
	if c == "" {
		writeError(w, http.StatusBadRequest, "invalid_request", "fehlende identitaet")
		return
	}
	err := trigger.Delete(r.Context(), s.pool, c, r.PathValue("id"))
	if errors.Is(err, trigger.ErrNotFound) {
		writeError(w, http.StatusNotFound, "not_found", "trigger nicht gefunden")
		return
	}
	if err != nil {
		writeError(w, http.StatusInternalServerError, "internal_error", err.Error())
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func (s *Server) handleSetEnabled(enabled bool) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		c := caller(r)
		if c == "" {
			writeError(w, http.StatusBadRequest, "invalid_request", "fehlende identitaet")
			return
		}
		err := trigger.SetEnabled(r.Context(), s.pool, c, r.PathValue("id"), enabled)
		if errors.Is(err, trigger.ErrNotFound) {
			writeError(w, http.StatusNotFound, "not_found", "trigger nicht gefunden")
			return
		}
		if err != nil {
			writeError(w, http.StatusInternalServerError, "internal_error", err.Error())
			return
		}
		w.WriteHeader(http.StatusNoContent)
	}
}