package api

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

	"github.com/go-chi/chi/v5"
	"github.com/restxlsx/restxlsx/internal/excel"
	"github.com/restxlsx/restxlsx/internal/logger"
)

type DDLHandler struct {
	engine *excel.Engine
	log    *logger.Logger
}

func NewDDLHandler(engine *excel.Engine, log *logger.Logger) *DDLHandler {
	return &DDLHandler{engine: engine, log: log}
}

type createSheetReq struct {
	Name string `json:"name"`
}

func (h *DDLHandler) CreateSheet(w http.ResponseWriter, r *http.Request) {
	var req createSheetReq
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeJSON(w, 400, map[string]string{"error": "invalid JSON: " + err.Error()})
		return
	}
	if req.Name == "" {
		writeJSON(w, 400, map[string]string{"error": "name is required"})
		return
	}

	h.engine.Lock()
	defer h.engine.Unlock()
	if err := h.engine.CreateSheet(req.Name); err != nil {
		writeJSON(w, 409, map[string]string{"error": err.Error()})
		return
	}
	if err := h.engine.Flush(); err != nil {
		writeJSON(w, 503, map[string]string{"error": "flush failed: " + err.Error()})
		return
	}
	writeJSON(w, 201, map[string]any{"sheet": req.Name, "status": "created"})
}

func (h *DDLHandler) DropSheet(w http.ResponseWriter, r *http.Request) {
	sheet := chi.URLParam(r, "sheet")
	if sheet == "" {
		writeJSON(w, 400, map[string]string{"error": "sheet name required"})
		return
	}
	h.engine.Lock()
	defer h.engine.Unlock()
	if err := h.engine.DropSheet(sheet); err != nil {
		writeJSON(w, 404, map[string]string{"error": err.Error()})
		return
	}
	if err := h.engine.Flush(); err != nil {
		writeJSON(w, 503, map[string]string{"error": "flush failed: " + err.Error()})
		return
	}
	writeJSON(w, 200, map[string]any{"sheet": sheet, "status": "deleted"})
}

type createTableReq struct {
	Sheet   string   `json:"sheet"`
	Name    string   `json:"name"`
	Columns []string `json:"columns"`
}

func (h *DDLHandler) CreateTable(w http.ResponseWriter, r *http.Request) {
	var req createTableReq
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeJSON(w, 400, map[string]string{"error": "invalid JSON: " + err.Error()})
		return
	}
	if req.Name == "" || req.Sheet == "" || len(req.Columns) == 0 {
		writeJSON(w, 400, map[string]string{"error": "sheet, name, and columns are required"})
		return
	}

	h.engine.Lock()
	defer h.engine.Unlock()
	if h.engine.GetTable(req.Sheet) == nil {
		if err := h.engine.CreateSheet(req.Sheet); err != nil {
			writeJSON(w, 409, map[string]string{"error": err.Error()})
			return
		}
	}

	if err := h.engine.CreateTable(req.Sheet, req.Columns, []map[string]any{}); err != nil {
		writeJSON(w, 409, map[string]string{"error": err.Error()})
		return
	}
	t := h.engine.GetTable(req.Sheet)
	t.Name = req.Name
	h.engine.Tables[req.Name] = t
	delete(h.engine.Tables, req.Sheet)

	if err := h.engine.Flush(); err != nil {
		writeJSON(w, 503, map[string]string{"error": "flush failed: " + err.Error()})
		return
	}
	writeJSON(w, 201, map[string]any{"table": req.Name, "sheet": req.Sheet, "columns": req.Columns, "status": "created"})
}

func (h *DDLHandler) DropTable(w http.ResponseWriter, r *http.Request) {
	table := chi.URLParam(r, "table")
	if table == "" {
		writeJSON(w, 400, map[string]string{"error": "table name required"})
		return
	}
	h.engine.Lock()
	defer h.engine.Unlock()
	if err := h.engine.DropTable(table); err != nil {
		writeJSON(w, 404, map[string]string{"error": err.Error()})
		return
	}
	if err := h.engine.Flush(); err != nil {
		writeJSON(w, 503, map[string]string{"error": "flush failed: " + err.Error()})
		return
	}
	writeJSON(w, 200, map[string]any{"table": table, "status": "deleted"})
}