package channel

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

	"git.dustin.coffee/hobokenchicken/dumpsterChat/internal/middleware"
	"git.dustin.coffee/hobokenchicken/dumpsterChat/internal/permissions"
	"github.com/go-chi/chi/v5"
)

type overrideRequest struct {
	Allow int64 `json:"allow"`
	Deny  int64 `json:"deny"`
}

type overrideResponse struct {
	ID        string `json:"id"`
	ChannelID string `json:"channel_id"`
	TargetType string `json:"target_type"`
	TargetID   string `json:"target_id"`
	Allow      int64  `json:"allow_bitflags"`
	Deny       int64  `json:"deny_bitflags"`
}

func (h *Handler) registerOverrideRoutes(r chi.Router) {
	r.Put("/{channelID}/permissions/{targetType}/{targetID}", h.SetOverride)
	r.Get("/{channelID}/permissions", h.ListOverrides)
	r.Delete("/{channelID}/permissions/{targetType}/{targetID}", h.DeleteOverride)
}

func (h *Handler) requireChannelManager(w http.ResponseWriter, r *http.Request, channelID string) (userID, serverID string, ok bool) {
	userID, authOK := middleware.UserIDFromContext(r.Context())
	if !authOK {
		http.Error(w, `{"error":"unauthorized"}`, http.StatusUnauthorized)
		return "", "", false
	}
	serverID, err := h.serverIDForChannel(r.Context(), channelID)
	if err != nil {
		http.Error(w, `{"error":"channel not found"}`, http.StatusNotFound)
		return "", "", false
	}
	allowed, err := h.checker.CheckPermission(r.Context(), serverID, userID, permissions.MANAGE_CHANNELS)
	if err != nil || !allowed {
		http.Error(w, `{"error":"forbidden"}`, http.StatusForbidden)
		return "", "", false
	}
	return userID, serverID, true
}

func (h *Handler) SetOverride(w http.ResponseWriter, r *http.Request) {
	channelID := chi.URLParam(r, "channelID")
	_, _, ok := h.requireChannelManager(w, r, channelID)
	if !ok {
		return
	}
	targetType := chi.URLParam(r, "targetType")
	targetID := chi.URLParam(r, "targetID")
	if targetType != "role" && targetType != "user" {
		http.Error(w, `{"error":"invalid target_type"}`, http.StatusBadRequest)
		return
	}
	var req overrideRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, `{"error":"invalid request"}`, http.StatusBadRequest)
		return
	}

	var res overrideResponse
	err := h.db.QueryRowContext(r.Context(), `
		INSERT INTO channel_overrides (channel_id, target_type, target_id, allow_bitflags, deny_bitflags)
		VALUES ($1, $2, $3, $4, $5)
		ON CONFLICT (channel_id, target_type, target_id)
		DO UPDATE SET allow_bitflags = EXCLUDED.allow_bitflags, deny_bitflags = EXCLUDED.deny_bitflags, updated_at = NOW()
		RETURNING id, channel_id, target_type, target_id, allow_bitflags, deny_bitflags
	`, channelID, targetType, targetID, req.Allow, req.Deny).Scan(&res.ID, &res.ChannelID, &res.TargetType, &res.TargetID, &res.Allow, &res.Deny)
	if err != nil {
		http.Error(w, `{"error":"failed to set override"}`, http.StatusInternalServerError)
		return
	}
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(res)
}

func (h *Handler) ListOverrides(w http.ResponseWriter, r *http.Request) {
	channelID := chi.URLParam(r, "channelID")
	_, _, ok := h.requireChannelManager(w, r, channelID)
	if !ok {
		return
	}
	rows, err := h.db.QueryContext(r.Context(), `
		SELECT id, channel_id, target_type, target_id, allow_bitflags, deny_bitflags
		FROM channel_overrides
		WHERE channel_id = $1
		ORDER BY target_type, target_id
	`, channelID)
	if err != nil {
		http.Error(w, `{"error":"server error"}`, http.StatusInternalServerError)
		return
	}
	defer rows.Close()
	overrides := make([]overrideResponse, 0)
	for rows.Next() {
		var o overrideResponse
		if err := rows.Scan(&o.ID, &o.ChannelID, &o.TargetType, &o.TargetID, &o.Allow, &o.Deny); err != nil {
			continue
		}
		overrides = append(overrides, o)
	}
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(overrides)
}

func (h *Handler) DeleteOverride(w http.ResponseWriter, r *http.Request) {
	channelID := chi.URLParam(r, "channelID")
	_, _, ok := h.requireChannelManager(w, r, channelID)
	if !ok {
		return
	}
	targetType := chi.URLParam(r, "targetType")
	targetID := chi.URLParam(r, "targetID")
	_, err := h.db.ExecContext(r.Context(), `
		DELETE FROM channel_overrides WHERE channel_id = $1 AND target_type = $2 AND target_id = $3
	`, channelID, targetType, targetID)
	if err != nil {
		http.Error(w, `{"error":"failed to delete override"}`, http.StatusInternalServerError)
		return
	}
	w.WriteHeader(http.StatusNoContent)
}