package handlers

import (
	"encoding/json"
	"net/http"
	"strconv"
	"time"
	"unicode/utf8"

	"github.com/gin-gonic/gin"

	"booklib/internal/store"
)

const maxNoteRunes = 500

func bookmarkJSON(b store.Bookmark) gin.H {
	return gin.H{
		"id": b.ID, "library_id": b.LibraryID, "path": b.BookPath,
		"locator": json.RawMessage(b.Locator), "percent": b.Percent,
		"note": b.Note, "created_at": b.CreatedAt.Format(time.RFC3339),
	}
}

func (h *H) ListBookmarks(c *gin.Context) {
	b, ok := h.bookFromParam(c)
	if !ok {
		return
	}
	rows, e := h.bookmarks.ListBookmarks(c, uid(c), b.LibraryID, b.Path)
	if e != nil {
		dbErr(c, e)
		return
	}
	out := make([]gin.H, 0, len(rows))
	for _, r := range rows {
		out = append(out, bookmarkJSON(r))
	}
	c.JSON(http.StatusOK, out)
}

func (h *H) CreateBookmark(c *gin.Context) {
	b, ok := h.bookFromParam(c)
	if !ok {
		return
	}
	var req struct {
		Locator json.RawMessage `json:"locator"`
		Percent float64         `json:"percent"`
		Note    string          `json:"note"`
	}
	if e := c.ShouldBindJSON(&req); e != nil {
		err(c, http.StatusBadRequest, "bad_request", "json body required")
		return
	}
	if len(req.Locator) == 0 || string(req.Locator) == "null" || !json.Valid(req.Locator) {
		err(c, http.StatusBadRequest, "bad_request", "locator must be valid json")
		return
	}
	if req.Percent < 0 || req.Percent > 1 {
		err(c, http.StatusBadRequest, "bad_request", "percent must be in [0,1]")
		return
	}
	if utf8.RuneCountInString(req.Note) > maxNoteRunes {
		err(c, http.StatusBadRequest, "bad_request", "note too long (max 500 characters)")
		return
	}
	id, e := h.bookmarks.InsertBookmark(c, uid(c), b.LibraryID, b.Path, req.Locator, req.Percent, req.Note)
	if e != nil {
		dbErr(c, e)
		return
	}
	c.JSON(http.StatusCreated, bookmarkJSON(store.Bookmark{
		ID: id, LibraryID: b.LibraryID, BookPath: b.Path,
		Locator: req.Locator, Percent: req.Percent, Note: req.Note, CreatedAt: time.Now(),
	}))
}

func bookmarkID(c *gin.Context) (int64, bool) {
	id, e := strconv.ParseInt(c.Param("id"), 10, 64)
	if e != nil {
		err(c, http.StatusBadRequest, "bad_request", "bad id")
		return 0, false
	}
	return id, true
}

func (h *H) PatchBookmark(c *gin.Context) {
	id, ok := bookmarkID(c)
	if !ok {
		return
	}
	var req struct {
		Note string `json:"note"`
	}
	if e := c.ShouldBindJSON(&req); e != nil {
		err(c, http.StatusBadRequest, "bad_request", "json body required")
		return
	}
	if utf8.RuneCountInString(req.Note) > maxNoteRunes {
		err(c, http.StatusBadRequest, "bad_request", "note too long (max 500 characters)")
		return
	}
	updated, e := h.bookmarks.UpdateBookmarkNote(c, uid(c), id, req.Note)
	if e != nil {
		dbErr(c, e)
		return
	}
	if !updated {
		err(c, http.StatusNotFound, "not_found", "no such bookmark")
		return
	}
	c.JSON(http.StatusOK, gin.H{"id": id, "note": req.Note})
}

func (h *H) DeleteBookmark(c *gin.Context) {
	id, ok := bookmarkID(c)
	if !ok {
		return
	}
	deleted, e := h.bookmarks.DeleteBookmark(c, uid(c), id)
	if e != nil {
		dbErr(c, e)
		return
	}
	if !deleted {
		err(c, http.StatusNotFound, "not_found", "no such bookmark")
		return
	}
	c.Status(http.StatusNoContent)
}