package main

import (
	"errors"
	"fmt"
	"mime"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"github.com/gin-gonic/gin"
)

var extraMimeTypes = map[string]string{
	".icon": "image-x-icon",
	".ttf":  "application/x-font-ttf",
	".woff": "application/x-font-woff",
	".eot":  "application/vnd.ms-fontobject",
	".svg":  "image/svg+xml",
}

type Error struct {
	Message string `json:"error"`
}

func NewError(err error) Error {
	return Error{err.Error()}
}

func assetContentType(name string) string {
	ext := filepath.Ext(name)
	result := mime.TypeByExtension(ext)

	if result == "" {
		result = extraMimeTypes[ext]
	}

	if result == "" {
		result = "text/plain; charset=utf-8"
	}

	return result
}

func setupRoutes(router *gin.Engine) {
	router.GET("/", API_Home)
	router.GET("/static/*path", API_ServeAsset)

	api := router.Group("/api")
	{
		api.Use(ApiMiddleware())

		api.POST("/connect", API_Connect)
		api.GET("/databases", API_GetDatabases)
		api.GET("/connection", API_ConnectionInfo)
		api.GET("/tables", API_GetTables)
		api.GET("/tables/:table", API_GetTable)
		api.GET("/tables/:table/rows", API_GetTableRows)
		api.GET("/tables/:table/info", API_GetTableInfo)
		api.GET("/tables/:table/indexes", API_TableIndexes)
		api.GET("/query", API_RunQuery)
		api.POST("/query", API_RunQuery)
		api.GET("/explain", API_ExplainQuery)
		api.POST("/explain", API_ExplainQuery)
		api.GET("/history", API_History)
		api.GET("/bookmarks", API_Bookmarks)
	}
}

// Middleware function to check database connection status before running queries
func ApiMiddleware() gin.HandlerFunc {
	allowedPaths := []string{
		"/api/connect",
		"/api/bookmarks",
		"/api/history",
	}

	return func(c *gin.Context) {
		if dbClient != nil {
			c.Next()
			return
		}

		currentPath := c.Request.URL.Path
		allowed := false

		for _, path := range allowedPaths {
			if path == currentPath {
				allowed = true
				break
			}
		}

		if allowed {
			c.Next()
		} else {
			c.JSON(400, Error{"Not connected"})
			c.Abort(400)
		}

		return
	}
}

func API_Home(c *gin.Context) {
	data, err := Asset("static/index.html")

	if err != nil {
		c.String(400, err.Error())
		return
	}

	c.Data(200, "text/html; charset=utf-8", data)
}

func API_Connect(c *gin.Context) {
	url := c.Request.FormValue("url")

	if url == "" {
		c.JSON(400, Error{"Url parameter is required"})
		return
	}

	opts := Options{Url: url}
	url, err := formatConnectionUrl(opts)

	if err != nil {
		c.JSON(400, Error{err.Error()})
		return
	}

	client, err := NewClientFromUrl(url)
	if err != nil {
		c.JSON(400, Error{err.Error()})
		return
	}

	err = client.Test()
	if err != nil {
		c.JSON(400, Error{err.Error()})
		return
	}

	info, err := client.Info()

	if err == nil {
		if dbClient != nil {
			dbClient.db.Close()
		}

		dbClient = client
	}

	c.JSON(200, info.Format()[0])
}

func API_GetDatabases(c *gin.Context) {
	names, err := dbClient.Databases()

	if err != nil {
		c.JSON(400, NewError(err))
		return
	}

	c.JSON(200, names)
}

func API_RunQuery(c *gin.Context) {
	query := strings.TrimSpace(c.Request.FormValue("query"))

	if query == "" {
		c.JSON(400, errors.New("Query parameter is missing"))
		return
	}

	API_HandleQuery(query, c)
}

func API_ExplainQuery(c *gin.Context) {
	query := strings.TrimSpace(c.Request.FormValue("query"))

	if query == "" {
		c.JSON(400, errors.New("Query parameter is missing"))
		return
	}

	API_HandleQuery(fmt.Sprintf("EXPLAIN ANALYZE %s", query), c)
}

func API_GetTables(c *gin.Context) {
	names, err := dbClient.Tables()

	if err != nil {
		c.JSON(400, NewError(err))
		return
	}

	c.JSON(200, names)
}

func API_GetTable(c *gin.Context) {
	res, err := dbClient.Table(c.Params.ByName("table"))

	if err != nil {
		c.JSON(400, NewError(err))
		return
	}

	c.JSON(200, res)
}

func API_GetTableRows(c *gin.Context) {
	limit := 1000 // Number of rows to fetch
	limitVal := c.Request.FormValue("limit")

	if limitVal != "" {
		num, err := strconv.Atoi(limitVal)

		if err != nil {
			c.JSON(400, Error{"Invalid limit value"})
			return
		}

		if num <= 0 {
			c.JSON(400, Error{"Limit should be greater than 0"})
			return
		}

		limit = num
	}

	opts := RowsOptions{
		Limit:      limit,
		SortColumn: c.Request.FormValue("sort_column"),
		SortOrder:  c.Request.FormValue("sort_order"),
	}

	res, err := dbClient.TableRows(c.Params.ByName("table"), opts)

	if err != nil {
		c.JSON(400, NewError(err))
		return
	}

	c.JSON(200, res)
}

func API_GetTableInfo(c *gin.Context) {
	res, err := dbClient.TableInfo(c.Params.ByName("table"))

	if err != nil {
		c.JSON(400, NewError(err))
		return
	}

	c.JSON(200, res.Format()[0])
}

func API_History(c *gin.Context) {
	c.JSON(200, dbClient.history)
}

func API_ConnectionInfo(c *gin.Context) {
	res, err := dbClient.Info()

	if err != nil {
		c.JSON(400, NewError(err))
		return
	}

	c.JSON(200, res.Format()[0])
}

func API_TableIndexes(c *gin.Context) {
	res, err := dbClient.TableIndexes(c.Params.ByName("table"))

	if err != nil {
		c.JSON(400, NewError(err))
		return
	}

	c.JSON(200, res)
}

func API_HandleQuery(query string, c *gin.Context) {
	result, err := dbClient.Query(query)

	if err != nil {
		c.JSON(400, NewError(err))
		return
	}

	q := c.Request.URL.Query()

	if len(q["format"]) > 0 && q["format"][0] == "csv" {
		filename := fmt.Sprintf("pgweb-%v.csv", time.Now().Unix())
		c.Writer.Header().Set("Content-disposition", "attachment;filename="+filename)
		c.Data(200, "text/csv", result.CSV())
		return
	}

	c.JSON(200, result)
}

func API_Bookmarks(c *gin.Context) {
	bookmarks, err := readAllBookmarks()

	if err != nil {
		c.JSON(400, NewError(err))
		return
	}

	c.JSON(200, bookmarks)
}

func API_ServeAsset(c *gin.Context) {
	path := "static" + c.Params.ByName("path")
	data, err := Asset(path)

	if err != nil {
		c.String(400, err.Error())
		return
	}

	if len(data) == 0 {
		c.String(404, "Asset is empty")
		return
	}

	c.Data(200, assetContentType(path), data)
}