package handlers

import (
	"context"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5/pgtype"

	"bookhoard/internal/database"
	"bookhoard/internal/utils"
)

// BookInfo is THE canonical wire+template card shape: every surface that
// lists a book card as JSON (collections detail, series, preview,
// dashboard sections, search) or renders a templ card (BookCard in
// dashboard.templ, BooksGrid, BrowseDetail) carries exactly these seven
// keys and no others — pinned by docs/contract_pins.md.
//
// H2 doctrine: this struct is constructed in EXACTLY ONE place —
// buildBookCard below, via the per-feed adapters. Direct BookInfo
// literals outside this file are a bug, not a style choice: before the
// builder, ten sites hand-rolled subsets of these fields, which is how
// badges vanished from the bookshelf and has_conflict stayed stamped
// false-forever on collections/series JSON.
type BookInfo struct {
	MediaItemID    string `json:"media_item_id"`
	Title          string `json:"title"`
	Author         string `json:"author"`
	CoverImagePath string `json:"cover_image_path"`
	HasConflict    bool   `json:"has_conflict"`
	// Media-type identifier for card badges/hover icons (A2c)
	FormatGroup string `json:"format_group"`
	// Resolved cover-badge glyph: "audiobook" | "comic" | "manga" | "".
	// comic vs manga rides the LIBRARY type (format_group only knows
	// comic_archive — manga_type is unreliable across sources).
	Badge string `json:"badge"`
}

// LibraryTypeMap builds libraryID→library-type-name for badge resolution
// (one small query per request; libraries are few).
//
// Call it ONCE per request and pass the map into the card adapters.
// Calling it inside a per-item loop was the old way — it re-ran
// ListLibraries for every card on the page.
func LibraryTypeMap(ctx context.Context, db *database.Queries) map[string]string {
	m := map[string]string{}
	libs, err := db.ListLibraries(ctx)
	if err != nil {
		return m
	}
	for _, l := range libs {
		if l.ID.Valid {
			m[uuid.UUID(l.ID.Bytes).String()] = l.TypeName
		}
	}
	return m
}

// MediaBadgeKind resolves the badge glyph per media type from the row's
// format group and its library's type name. The library type is
// authoritative for the comic/manga split: manga volumes ship as
// fixed_layout scans (image PDFs) just as often as comic_archive, and
// manga_type is unreliable across sources (unknown/NULL on real rows),
// so anything in a manga library reads manga, anything in a comics
// library reads comic, and a stray comic_archive elsewhere still does.
func MediaBadgeKind(formatGroup, libraryTypeName string) string {
	switch {
	case formatGroup == "audiobook":
		return "audiobook"
	case libraryTypeName == "manga":
		return "manga"
	case formatGroup == "comic_archive" || libraryTypeName == "comics":
		return "comic"
	}
	return ""
}

// buildBookCard is the single construction site for BookInfo. Feed
// adapters below normalize the sqlc row shapes into cardSource.
func buildBookCard(src cardSource) BookInfo {
	return BookInfo{
		MediaItemID:    src.ID.String(),
		Title:          src.Title,
		Author:         src.Author,
		CoverImagePath: utils.ResolveMediaURL(src.LibraryID, src.CoverPath),
		FormatGroup:    src.FormatGroup,
		Badge:          MediaBadgeKind(src.FormatGroup, src.LibraryType),
	}
}

// HasConflict is deliberately absent here: conflict stamping is a
// per-user query (MarkActiveConflicts), done AFTER the cards are built
// by the surfaces that carry it. Builders stay user-free.

// cardSource is the neutral input to the builder core: whatever fields
// every card feed row provably has.
type cardSource struct {
	ID          uuid.UUID
	Title       string
	Author      string
	LibraryID   pgtype.UUID
	CoverPath   pgtype.Text
	FormatGroup string
	LibraryType string
}

// BookCardsFromMediaItems builds cards from full media rows
// (dashboard sections, smart-collection matches, series/tag books,
// preview matches). libTypes must come from ONE LibraryTypeMap call
// per request, not per row.
func BookCardsFromMediaItems(rows []database.MediaItems, libTypes map[string]string) []BookInfo {
	cards := make([]BookInfo, 0, len(rows))
	for _, r := range rows {
		cards = append(cards, buildBookCard(cardSource{
			ID:          uuid.UUID(r.ID.Bytes),
			Title:       r.Title,
			Author:      textToString(r.Author),
			LibraryID:   r.LibraryID,
			CoverPath:   r.CoverImagePath,
			FormatGroup: r.FormatGroup,
			LibraryType: libTypes[uuid.UUID(r.LibraryID.Bytes).String()],
		}))
	}
	return cards
}

// BookCardsFromCollectionDashRows builds cards from the
// collection-items join (GetCollectionItemsForDashboard). The row's ID
// IS the media item id. The Excluded filter stays at call sites — only
// the two collection-detail surfaces exclude tombstones.
func BookCardsFromCollectionDashRows(rows []database.GetCollectionItemsForDashboardRow, libTypes map[string]string) []BookInfo {
	cards := make([]BookInfo, 0, len(rows))
	for _, r := range rows {
		cards = append(cards, buildBookCard(cardSource{
			ID:          uuid.UUID(r.ID.Bytes),
			Title:       r.Title,
			Author:      textToString(r.Author),
			LibraryID:   r.LibraryID,
			CoverPath:   r.CoverImagePath,
			FormatGroup: r.FormatGroup,
			LibraryType: libTypes[uuid.UUID(r.LibraryID.Bytes).String()],
		}))
	}
	return cards
}

// BookCardsFromCollectionItemRows builds cards from GetCollectionItems
// rows, whose ID is the collection-item id and whose MediaItemID is the
// book — the SSR all-libraries collection branch and the JSON
// no-library branch both feed from this shape.
func BookCardsFromCollectionItemRows(rows []database.GetCollectionItemsRow, libTypes map[string]string) []BookInfo {
	cards := make([]BookInfo, 0, len(rows))
	for _, r := range rows {
		cards = append(cards, buildBookCard(cardSource{
			ID:          uuid.UUID(r.MediaItemID.Bytes),
			Title:       r.Title,
			Author:      textToString(r.Author),
			LibraryID:   r.LibraryID,
			CoverPath:   r.CoverImagePath,
			FormatGroup: r.FormatGroup,
			LibraryType: libTypes[uuid.UUID(r.LibraryID.Bytes).String()],
		}))
	}
	return cards
}

// BookCardsFromUnified builds cards from search-unified rows. Those
// rows carry the library type name as a SQL column, so this adapter
// needs no LibraryTypeMap query at all.
func BookCardsFromUnified(rows []database.SearchMediaItemsUnifiedRow) []BookInfo {
	cards := make([]BookInfo, 0, len(rows))
	for _, r := range rows {
		cards = append(cards, buildBookCard(cardSource{
			ID:          uuid.UUID(r.ID.Bytes),
			Title:       r.Title,
			Author:      textToString(r.Author),
			LibraryID:   r.LibraryID,
			CoverPath:   r.CoverImagePath,
			FormatGroup: r.FormatGroup,
			LibraryType: r.LibraryTypeName,
		}))
	}
	return cards
}