package routes

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"path/filepath"
	"strings"
)

func (rt *Router) CreateSimulation(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Access-Control-Allow-Origin", "*")

	bodyBytes, err := io.ReadAll(r.Body)
	if err != nil {
		http.Error(w, "Failed to read request body", http.StatusBadRequest)
		return
	}
	defer r.Body.Close()
	configStr := string(bodyBytes)

	if configStr == "" {
		http.Error(w, "Config cannot be empty", http.StatusBadRequest)
		return
	}

	hasPattern := false
	var jsonParsed map[string]interface{}
	err = json.Unmarshal(bodyBytes, &jsonParsed)
	if err != nil {
		http.Error(w, "Invalid configuration format: must be valid JSON", http.StatusBadRequest)
		return
	}

	for k, v := range jsonParsed {
		if k == "search.yaml" || k == "search" {
			if searchMap, ok := v.(map[string]interface{}); ok {
				if _, ok := searchMap["spiral"]; ok {
					hasPattern = true
				}
				if _, ok := searchMap["lawnmower"]; ok {
					hasPattern = true
				}
				if _, ok := searchMap["levy"]; ok {
					hasPattern = true
				}
			}
		}
	}

	if !hasPattern {
		http.Error(w, "Simulation configuration must include a search pattern (spiral, lawnmower, or levy)", http.StatusBadRequest)
		return
	}



	var count int
	rt.DB.QueryRow("SELECT COUNT(*) FROM simulations").Scan(&count)
	newName := fmt.Sprintf("simulation_%d", count+1)

	for {
		var temp int
		err := rt.DB.QueryRow("SELECT id FROM simulations WHERE name = ?", newName).Scan(&temp)
		if err == sql.ErrNoRows {
			break
		}
		count++
		newName = fmt.Sprintf("simulation_%d", count+1)
	}

	res, err := rt.DB.Exec("INSERT INTO simulations(name, config) VALUES(?, ?)", newName, configStr)
	if err != nil {
		log.Println("Insert simulation error:", err)
		http.Error(w, "Failed to create", http.StatusInternalServerError)
		return
	}
	newID, _ := res.LastInsertId()

	resultsDir := filepath.Join("../results", newName)
	os.MkdirAll(resultsDir, 0755)

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]interface{}{
		"id":   newID,
		"name": newName,
	})
}

func (rt *Router) GetSimulations(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Access-Control-Allow-Origin", "*")

	rows, err := rt.DB.Query("SELECT id, name, config, created_at, search_time, total_time, cpu_info, gpu_info, ram_info FROM simulations")
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	defer rows.Close()

	var sims []Simulation
	for rows.Next() {
		var s Simulation
		err = rows.Scan(&s.ID, &s.Name, &s.Config, &s.CreatedAt, &s.SearchTime, &s.TotalTime, &s.CPUInfo, &s.GPUInfo, &s.RAMInfo)
		if err != nil {
			log.Println("Row scan error:", err)
			continue
		}
		sims = append(sims, s)
	}

	if sims == nil {
		sims = []Simulation{}
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(sims)
}

func (rt *Router) GetSimulationDetails(w http.ResponseWriter, r *http.Request, idStr string) {
	w.Header().Set("Access-Control-Allow-Origin", "*")

	var s Simulation
	err := rt.DB.QueryRow("SELECT id, name, config, created_at, search_time, total_time, cpu_info, gpu_info, ram_info FROM simulations WHERE id = ?", idStr).Scan(&s.ID, &s.Name, &s.Config, &s.CreatedAt, &s.SearchTime, &s.TotalTime, &s.CPUInfo, &s.GPUInfo, &s.RAMInfo)
	if err != nil {
		if err == sql.ErrNoRows {
			http.Error(w, "Simulation not found", http.StatusNotFound)
		} else {
			http.Error(w, err.Error(), http.StatusInternalServerError)
		}
		return
	}

	rows, err := rt.DB.Query("SELECT filename FROM resources WHERE simulation_id = ?", s.ID)
	if err == nil {
		defer rows.Close()
		for rows.Next() {
			var fname string
			if err := rows.Scan(&fname); err == nil {
				s.Resources = append(s.Resources, fname)
				if stat, err := os.Stat(filepath.Join("../results", s.Name, fname)); err == nil {
					s.TotalSizeBytes += stat.Size()
				}
			}
		}
	}
	if s.Resources == nil {
		s.Resources = []string{}
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(s)
}

func (rt *Router) RenameSimulation(w http.ResponseWriter, r *http.Request, idStr string) {
	w.Header().Set("Access-Control-Allow-Origin", "*")

	var reqBody struct {
		Name string `json:"name"`
	}

	err := json.NewDecoder(r.Body).Decode(&reqBody)
	if err != nil || strings.TrimSpace(reqBody.Name) == "" {
		http.Error(w, "Invalid request body or missing name", http.StatusBadRequest)
		return
	}
	defer r.Body.Close()

	newName := strings.TrimSpace(reqBody.Name)

	var oldName string
	err = rt.DB.QueryRow("SELECT name FROM simulations WHERE id = ?", idStr).Scan(&oldName)
	if err != nil {
		http.Error(w, "Simulation not found", http.StatusNotFound)
		return
	}

	var tempID int
	err = rt.DB.QueryRow("SELECT id FROM simulations WHERE name = ?", newName).Scan(&tempID)
	if err == nil {
		http.Error(w, "A simulation with that name already exists", http.StatusConflict)
		return
	}

	oldDirPath := filepath.Join("../results", oldName)
	newDirPath := filepath.Join("../results", newName)
	if _, statErr := os.Stat(oldDirPath); statErr == nil {
		err = os.Rename(oldDirPath, newDirPath)
		if err != nil {
			log.Println("Error renaming directory:", err)
			http.Error(w, "Failed to rename results directory", http.StatusInternalServerError)
			return
		}
	} else {
		os.MkdirAll(newDirPath, 0755)
	}

	_, err = rt.DB.Exec("UPDATE simulations SET name = ? WHERE id = ?", newName, idStr)
	if err != nil {
		os.Rename(newDirPath, oldDirPath)
		log.Println("Update simulation name error:", err)
		http.Error(w, "Failed to update database", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]string{"status": "success", "new_name": newName})
}

func (rt *Router) DeleteSimulation(w http.ResponseWriter, r *http.Request, idStr string) {
	w.Header().Set("Access-Control-Allow-Origin", "*")

	var name string
	err := rt.DB.QueryRow("SELECT name FROM simulations WHERE id = ?", idStr).Scan(&name)
	if err != nil {
		if err == sql.ErrNoRows {
			http.Error(w, "Simulation not found", http.StatusNotFound)
		} else {
			http.Error(w, err.Error(), http.StatusInternalServerError)
		}
		return
	}

	_, err = rt.DB.Exec("DELETE FROM resources WHERE simulation_id = ?", idStr)
	if err != nil {
		log.Println("Warning: Error deleting resources map from DB:", err)
	}
	
	_, err = rt.DB.Exec("DELETE FROM simulations WHERE id = ?", idStr)
	if err != nil {
		log.Println("Error deleting simulation from DB:", err)
		http.Error(w, "Failed to delete from database", http.StatusInternalServerError)
		return
	}

	dirPath := filepath.Join("../results", name)
	if _, statErr := os.Stat(dirPath); statErr == nil {
		err = os.RemoveAll(dirPath)
		if err != nil {
			log.Println("Warning: Failed fully deleting physical directory items:", err)
		}
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]string{"status": "success"})
}