package main

import (
	"github.com/gin-gonic/gin"
    "database/sql"
	"log"
	"os"
	"fmt"
	"strconv"
    _ "github.com/mattn/go-sqlite3"
)

func main() {
	database_path, ok := os.LookupEnv("DB_PATH")
	if !ok {
		log.Fatal("Environment variable $DB_PATH must point to sqlite3 database with text indices.")
		os.Exit(1)
	}

	port := 3000
	port_str, ok := os.LookupEnv("PORT")
	if ok {
		port_num, err := strconv.Atoi(port_str)

		if err != nil {
			log.Fatal(err)
			os.Exit(1)
		}
		if (port_num < 1) || (port_num > 65535) {
			log.Fatal("Environment variale $PORT must be a number between 1 and 65535.")
			os.Exit(1)
		}
		port = port_num
	}

    db, err := sql.Open("sqlite3", database_path)
    if err != nil {
        log.Fatal(err)
		os.Exit(1)
    }

	r := gin.Default()

	api := r.Group("/api")

	api.GET("/ping", func(c *gin.Context) {
		c.JSON(200, gin.H{
			"message": "pong",
		})
	})

	api.OPTIONS("/search", func(c *gin.Context) {
		c.Writer.Header().Set("Access-Control-Allow-Origin", "*")
        c.Writer.Header().Set("Access-Control-Allow-Headers", "Accept-Encoding, Authorization, accept, origin, Cache-Control, X-Requested-With")
        c.Writer.Header().Set("Access-Control-Allow-Methods", "GET, OPTIONS")

		c.AbortWithStatus(204)
	})

	api.GET("/search", func(c *gin.Context) {
		c.Writer.Header().Set("Access-Control-Allow-Origin", "*")
        c.Writer.Header().Set("Access-Control-Allow-Headers", "Accept-Encoding, Authorization, accept, origin, Cache-Control, X-Requested-With")
        c.Writer.Header().Set("Access-Control-Allow-Methods", "GET, OPTIONS")

		query := c.Query("q")

		stm, err := db.Prepare("SELECT note_id, title FROM note_search WHERE title LIKE ?")

		if err != nil {
			log.Fatal(err)
			c.JSON(500, gin.H{
				"success": false,
				"message": "Error preparing note-search query",
			})
			return
		}

		results := make([]map[string]string, 0)

		rows, err := stm.Query(fmt.Sprintf("%%%v%%", query))
		if err != nil {
			log.Fatal(err)
			c.JSON(500, gin.H{
				"success": false,
				"message": "Error querying note DB",
			})
			return
		}

		for rows.Next() {
			var note_id string
			var note_title string

			err = rows.Scan(&note_id, &note_title)
			if err != nil {
				log.Fatal(err)
				c.JSON(500, gin.H{
					"success": false,
					"message": "Error reading note DB results",
				})
				return
			}

			item := make(map[string]string)
			item["id"] = note_id
			item["title"] = note_title
			results = append(results, item)
		}

		c.JSON(200, gin.H{
			"results": gin.H{
				"notes": results,
			},
		})
	})

	r.Run(fmt.Sprintf(":%v", port))
}