package api

import (
	"fmt"
	"mime/multipart"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/gabriel-vasile/mimetype"
	"github.com/gin-gonic/gin"
	log "github.com/sirupsen/logrus"
	"golang.org/x/exp/slices"
	"reichard.io/bbank/database"
	"reichard.io/bbank/metadata"
)

type requestDocumentEdit struct {
	Title       *string               `form:"title"`
	Author      *string               `form:"author"`
	Description *string               `form:"description"`
	RemoveCover *string               `form:"remove_cover"`
	CoverFile   *multipart.FileHeader `form:"cover"`
}

func baseResourceRoute(template string, args ...map[string]any) func(c *gin.Context) {
	variables := gin.H{"RouteName": template}
	if len(args) > 0 {
		variables = args[0]
	}

	return func(c *gin.Context) {
		rUser, _ := c.Get("AuthorizedUser")
		variables["User"] = rUser
		c.HTML(http.StatusOK, template, variables)
	}
}

func (api *API) webManifest(c *gin.Context) {
	c.Header("Content-Type", "application/manifest+json")
	c.File("./assets/manifest.json")
}

func (api *API) createAppResourcesRoute(routeName string, args ...map[string]any) func(*gin.Context) {
	// Merge Optional Template Data
	var templateVarsBase = gin.H{}
	if len(args) > 0 {
		templateVarsBase = args[0]
	}
	templateVarsBase["RouteName"] = routeName

	return func(c *gin.Context) {
		rUser, _ := c.Get("AuthorizedUser")

		// Copy Base & Update
		templateVars := gin.H{}
		for k, v := range templateVarsBase {
			templateVars[k] = v
		}
		templateVars["User"] = rUser

		// Potential URL Parameters
		qParams := bindQueryParams(c)

		if routeName == "documents" {
			documents, err := api.DB.Queries.GetDocumentsWithStats(api.DB.Ctx, database.GetDocumentsWithStatsParams{
				UserID: rUser.(string),
				Offset: (*qParams.Page - 1) * *qParams.Limit,
				Limit:  *qParams.Limit,
			})
			if err != nil {
				log.Error("[createAppResourcesRoute] GetDocumentsWithStats DB Error:", err)
				c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
				return
			}

			templateVars["Data"] = documents
		} else if routeName == "document" {
			var rDocID requestDocumentID
			if err := c.ShouldBindUri(&rDocID); err != nil {
				log.Error("[createAppResourcesRoute] Invalid URI Bind")
				c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
				return
			}

			document, err := api.DB.Queries.GetDocumentWithStats(api.DB.Ctx, database.GetDocumentWithStatsParams{
				UserID:     rUser.(string),
				DocumentID: rDocID.DocumentID,
			})
			if err != nil {
				log.Error("[createAppResourcesRoute] GetDocumentWithStats DB Error:", err)
				c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
				return
			}

			templateVars["Data"] = document
		} else if routeName == "document-edit" {
			var rDocID requestDocumentID
			if err := c.ShouldBindUri(&rDocID); err != nil {
				log.Error("[createAppResourcesRoute] Invalid URI Bind")
				c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
				return
			}

			var rDocEdit requestDocumentEdit
			if err := c.ShouldBind(&rDocEdit); err != nil {
				log.Error("[createAppResourcesRoute] Invalid Form Bind")
				c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
				return
			}

			// Validate Something Exists
			if rDocEdit.Author == nil &&
				rDocEdit.Title == nil &&
				rDocEdit.Description == nil &&
				rDocEdit.CoverFile == nil &&
				rDocEdit.RemoveCover == nil {
				log.Error("[createAppResourcesRoute] Missing Form Values")
				c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
				return
			}

			// Handle Cover
			var coverFileName *string
			if rDocEdit.RemoveCover != nil && *rDocEdit.RemoveCover == "on" {
				s := "UNKNOWN"
				coverFileName = &s
			} else if rDocEdit.CoverFile != nil {

				// Validate Type & Derive Extension on MIME
				uploadedFile, err := rDocEdit.CoverFile.Open()
				if err != nil {
					log.Error("[createAppResourcesRoute] File Error")
					c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
					return
				}

				fileMime, err := mimetype.DetectReader(uploadedFile)
				if err != nil {
					log.Error("[createAppResourcesRoute] MIME Error")
					c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
					return
				}
				fileExtension := fileMime.Extension()

				// Validate Extension
				if !slices.Contains([]string{".jpg", ".png"}, fileExtension) {
					log.Error("[uploadDocumentFile] Invalid FileType: ", fileExtension)
					c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Filetype"})
					return
				}

				// Generate Storage Path
				fileName := fmt.Sprintf("%s%s", rDocID.DocumentID, fileExtension)
				safePath := filepath.Join(api.Config.DataPath, "covers", fileName)

				// Save
				err = c.SaveUploadedFile(rDocEdit.CoverFile, safePath)
				if err != nil {
					log.Error("[createAppResourcesRoute] File Error")
					c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
					return
				}

				coverFileName = &fileName
			}

			// Update Document
			if _, err := api.DB.Queries.UpsertDocument(api.DB.Ctx, database.UpsertDocumentParams{
				ID:          rDocID.DocumentID,
				Title:       api.sanitizeInput(rDocEdit.Title),
				Author:      api.sanitizeInput(rDocEdit.Author),
				Description: api.sanitizeInput(rDocEdit.Description),
				Coverfile:   coverFileName,
			}); err != nil {
				log.Error("[createAppResourcesRoute] UpsertDocument DB Error:", err)
				c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
				return
			}

			c.Redirect(http.StatusFound, "./")
			return
		} else if routeName == "activity" {
			activityFilter := database.GetActivityParams{
				UserID: rUser.(string),
				Offset: (*qParams.Page - 1) * *qParams.Limit,
				Limit:  *qParams.Limit,
			}

			if qParams.Document != nil {
				activityFilter.DocFilter = true
				activityFilter.DocumentID = *qParams.Document
			}

			activity, err := api.DB.Queries.GetActivity(api.DB.Ctx, activityFilter)
			if err != nil {
				log.Error("[createAppResourcesRoute] GetActivity DB Error:", err)
				c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
				return
			}

			templateVars["Data"] = activity
		} else if routeName == "home" {
			start_time := time.Now()
			weekly_streak, err := api.DB.Queries.GetUserWindowStreaks(api.DB.Ctx, database.GetUserWindowStreaksParams{
				UserID: rUser.(string),
				Window: "WEEK",
			})
			if err != nil {
				log.Warn("[createAppResourcesRoute] GetUserWindowStreaks DB Error:", err)
			}
			log.Info("GetUserWindowStreaks - WEEK - ", time.Since(start_time))
			start_time = time.Now()

			daily_streak, err := api.DB.Queries.GetUserWindowStreaks(api.DB.Ctx, database.GetUserWindowStreaksParams{
				UserID: rUser.(string),
				Window: "DAY",
			})
			if err != nil {
				log.Warn("[createAppResourcesRoute] GetUserWindowStreaks DB Error:", err)
			}
			log.Info("GetUserWindowStreaks - DAY - ", time.Since(start_time))

			start_time = time.Now()
			database_info, _ := api.DB.Queries.GetDatabaseInfo(api.DB.Ctx, rUser.(string))
			log.Info("GetDatabaseInfo - ", time.Since(start_time))

			start_time = time.Now()
			read_graph_data, _ := api.DB.Queries.GetDailyReadStats(api.DB.Ctx, rUser.(string))
			log.Info("GetDailyReadStats - ", time.Since(start_time))

			templateVars["Data"] = gin.H{
				"DailyStreak":  daily_streak,
				"WeeklyStreak": weekly_streak,
				"DatabaseInfo": database_info,
				"GraphData":    read_graph_data,
			}
		} else if routeName == "login" {
			templateVars["RegistrationEnabled"] = api.Config.RegistrationEnabled
		}

		c.HTML(http.StatusOK, routeName, templateVars)
	}
}

func (api *API) getDocumentCover(c *gin.Context) {
	var rDoc requestDocumentID
	if err := c.ShouldBindUri(&rDoc); err != nil {
		log.Error("[getDocumentCover] Invalid URI Bind")
		c.AbortWithStatus(http.StatusBadRequest)
		return
	}

	// Validate Document Exists in DB
	document, err := api.DB.Queries.GetDocument(api.DB.Ctx, rDoc.DocumentID)
	if err != nil {
		log.Error("[getDocumentCover] GetDocument DB Error:", err)
		c.AbortWithStatus(http.StatusBadRequest)
		return
	}

	// Handle Identified Document
	if document.Coverfile != nil {
		if *document.Coverfile == "UNKNOWN" {
			c.File("./assets/no-cover.jpg")
			return
		}

		// Derive Path
		safePath := filepath.Join(api.Config.DataPath, "covers", *document.Coverfile)

		// Validate File Exists
		_, err = os.Stat(safePath)
		if err != nil {
			log.Error("[getDocumentCover] File Should But Doesn't Exist:", err)
			c.File("./assets/no-cover.jpg")
			return
		}

		c.File(safePath)
		return
	}

	// --- Attempt Metadata ---

	var coverDir string = filepath.Join(api.Config.DataPath, "covers")
	var coverFile string = "UNKNOWN"

	// Identify Documents & Save Covers
	metadataResults, err := metadata.GetMetadata(metadata.MetadataInfo{
		Title:  document.Title,
		Author: document.Author,
	})

	if err == nil && len(metadataResults) > 0 && metadataResults[0].GBID != nil {
		firstResult := metadataResults[0]

		// Save Cover
		fileName, err := metadata.SaveCover(*firstResult.GBID, coverDir, document.ID)
		if err == nil {
			coverFile = *fileName
		}

		// Store First Metadata Result
		if _, err = api.DB.Queries.AddMetadata(api.DB.Ctx, database.AddMetadataParams{
			DocumentID:  document.ID,
			Title:       firstResult.Title,
			Author:      firstResult.Author,
			Description: firstResult.Description,
			Gbid:        firstResult.GBID,
			Olid:        firstResult.OLID,
			Isbn10:      firstResult.ISBN10,
			Isbn13:      firstResult.ISBN13,
		}); err != nil {
			log.Error("[getDocumentCover] AddMetadata DB Error:", err)
		}
	}

	// Upsert Document
	if _, err = api.DB.Queries.UpsertDocument(api.DB.Ctx, database.UpsertDocumentParams{
		ID:        document.ID,
		Coverfile: &coverFile,
	}); err != nil {
		log.Warn("[getDocumentCover] UpsertDocument DB Error:", err)
	}

	// Return Unknown Cover
	if coverFile == "UNKNOWN" {
		c.File("./assets/no-cover.jpg")
		return
	}

	coverFilePath := filepath.Join(coverDir, coverFile)
	c.File(coverFilePath)
}

// DELETE /api/documents/:document
func (api *API) deleteDocument(c *gin.Context) {
	var rDocID requestDocumentID
	if err := c.ShouldBindUri(&rDocID); err != nil {
		log.Error("[deleteDocument] Invalid URI Bind")
		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
		return
	}
	changed, err := api.DB.Queries.DeleteDocument(api.DB.Ctx, rDocID.DocumentID)
	if err != nil {
		log.Error("[deleteDocument] DeleteDocument DB Error")
		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
		return
	}
	if changed == 0 {
		log.Error("[deleteDocument] DeleteDocument DB Error")
		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Unknown Document"})
		return
	}

	c.Redirect(http.StatusFound, "../")
}

// POST /api/documents/:document/identify
func (api *API) identifyDocument(c *gin.Context) {
	var rDocID requestDocumentID
	if err := c.ShouldBindUri(&rDocID); err != nil {
		log.Error("[identifyDocument] Invalid URI Bind")
		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
		return
	}

	isbn := strings.TrimSpace(c.PostForm("ISBN"))
	if isbn == "" {
		log.Error("[identifyDocument] Invalid Form")
		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Invalid Request"})
		return
	}

	metadataResults, err := metadata.GetMetadata(metadata.MetadataInfo{
		ISBN10: &isbn,
		ISBN13: &isbn,
	})
	if err != nil || len(metadataResults) == 0 {
		log.Error("[identifyDocument] Metadata Error")
		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": "Metadata Error"})
		return
	}

	// TODO
	firstResult := metadataResults[0]

	if firstResult.Title != nil {
		log.Info("Title:", *firstResult.Title)
	}
	if firstResult.Author != nil {
		log.Info("Author:", *firstResult.Author)
	}
	if firstResult.Description != nil {
		log.Info("Description:", *firstResult.Description)
	}
	if firstResult.ISBN10 != nil {
		log.Info("ISBN 10:", *firstResult.ISBN10)
	}
	if firstResult.ISBN13 != nil {
		log.Info("ISBN 13:", *firstResult.ISBN13)
	}

	c.Redirect(http.StatusFound, "/")
}