Dinner detail API (Feature 15) (#143)

Co-authored-by: orchestrator-agent <20+orchestrator-agent@code.cubecraftcreations.com>

internal/dinners/detail.go

@@ -0,0 +1,218 @@
+package dinners
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"net"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/db"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/recipes"
+)
+
+// Detail is a dinner with its recipe, as the recipe detail screen and
+// Kitchen reading mode show it.
+type Detail struct {
+	ID           string  `json:"id"`
+	Name         string  `json:"name"`
+	Status       string  `json:"status"`
+	Origin       string  `json:"origin"`
+	Method       *string `json:"method"`
+	MinutesTotal *int64  `json:"minutes_total"`
+	Difficulty   *string `json:"difficulty"`
+	Cuisine      *string `json:"cuisine"`
+	IsFavorite   bool    `json:"is_favorite"`
+	// PhotoURLs is the cached photo at each stored width, keyed by width
+	// ("400", "1200"); null when the dinner has no photo.
+	PhotoURLs map[string]string `json:"photo_urls"`
+	// Ingredients and Steps are the recipe's, in recipe order; empty when
+	// the dinner has no recipe.
+	Ingredients []Ingredient `json:"ingredients"`
+	Steps       []string     `json:"steps"`
+	// Source is the site of the recipe page the dinner is grounded in;
+	// null for a recipe entered by hand or a dinner with no recipe.
+	Source          *Source `json:"source"`
+	GroundingStatus string  `json:"grounding_status"`
+	// GroundingError is why grounding failed, one of the Reason codes;
+	// null unless GroundingStatus is failed.
+	GroundingError *string `json:"grounding_error"`
+	// WhyPicked is the reason of the suggestion that created the dinner
+	// (see GetDinnerSuggestionReasons); null for a dinner no suggestion
+	// created.
+	WhyPicked *string `json:"why_picked"`
+}
+
+// Ingredient is one recipe line. RawText is the line as the recipe gives
+// it; Name, Qty, Unit and Note are normalize_recipe's reading of it, each
+// null when it has none, and Name, Qty and Unit always null for a recipe
+// entered by hand (see IsManualRecipe).
+type Ingredient struct {
+	Name    *string `json:"name"`
+	Qty     *string `json:"qty"`
+	Unit    *string `json:"unit"`
+	Note    *string `json:"note"`
+	RawText string  `json:"raw_text"`
+}
+
+// Source is the site a recipe was fetched from. It has no url: the page's
+// link, pasted or offered as a candidate, may carry a personal token, and
+// no stored link can be shown to be free of one, so like a dinner's
+// recipe_url and a candidate's page it never leaves the server. SiteName
+// is the name the page itself gives its site, and null when it gives none
+// or the stored name could have come from a link (see pageSiteName), so a
+// client shows "Recipe from {site}" only when SiteName is not null.
+type Source struct {
+	SiteName *string `json:"site_name"`
+}
+
+// Get returns dinner id with its recipe and the reason it was suggested,
+// read in one read transaction. An unknown or archived dinner is
+// ErrNotFound: an archived dinner has no detail to show.
+func (s *Service) Get(ctx context.Context, id string) (d Detail, err error) {
+	tx, err := s.st.Reader.BeginTx(ctx, nil)
+	if err != nil {
+		return Detail{}, fmt.Errorf("dinners: begin read: %w", err)
+	}
+	defer func() {
+		err = errors.Join(err, tx.Rollback())
+	}()
+	q := db.New(tx)
+	row, err := q.GetDinner(ctx, id)
+	if errors.Is(err, sql.ErrNoRows) {
+		return Detail{}, ErrNotFound
+	}
+	if err != nil {
+		return Detail{}, fmt.Errorf("dinners: read %s: %w", id, err)
+	}
+	if row.Status == StatusArchived {
+		return Detail{}, ErrNotFound
+	}
+	d = Detail{
+		ID:              row.ID,
+		Name:            row.Name,
+		Status:          row.Status,
+		Origin:          row.Origin,
+		Method:          nullString(row.Method),
+		Difficulty:      nullString(row.Difficulty),
+		Cuisine:         nullString(row.Cuisine),
+		IsFavorite:      row.IsFavorite == 1,
+		Ingredients:     []Ingredient{},
+		Steps:           []string{},
+		GroundingStatus: row.GroundingStatus,
+		GroundingError:  nullString(row.GroundingError),
+	}
+	if row.MinutesTotal.Valid {
+		d.MinutesTotal = &row.MinutesTotal.Int64
+	}
+	if row.PhotoID.Valid {
+		d.PhotoURLs = make(map[string]string, len(recipes.PhotoSizes))
+		for _, size := range recipes.PhotoSizes {
+			d.PhotoURLs[strconv.Itoa(size)] = photoURL(row.PhotoID.String, size)
+		}
+	}
+	if (row.GroundingStatus == GroundingGrounded || row.GroundingStatus == GroundingManual) && !row.RecipeID.Valid {
+		return Detail{}, fmt.Errorf("dinners: %s is %s with no recipe", id, row.GroundingStatus)
+	}
+	if row.RecipeID.Valid {
+		if err := readRecipe(ctx, q, row.RecipeID.String, &d); err != nil {
+			return Detail{}, fmt.Errorf("dinners: read recipe of %s: %w", id, err)
+		}
+	}
+	reasons, err := q.GetDinnerSuggestionReasons(ctx, id)
+	if err != nil {
+		return Detail{}, fmt.Errorf("dinners: read suggestion reason of %s: %w", id, err)
+	}
+	switch len(reasons) {
+	case 0:
+	case 1:
+		d.WhyPicked = &reasons[0]
+	default:
+		// Nothing records which of them created the dinner, and any
+		// one picked would be a guess.
+		return Detail{}, fmt.Errorf("dinners: %s has %d suggestions that could have created it", id, len(reasons))
+	}
+	return d, nil
+}
+
+// readRecipe sets d's Source, Ingredients and Steps from recipe recipeID.
+func readRecipe(ctx context.Context, q *db.Queries, recipeID string, d *Detail) error {
+	rec, err := q.GetRecipe(ctx, recipeID)
+	if err != nil {
+		return fmt.Errorf("recipe %s: %w", recipeID, err)
+	}
+	if !IsManualRecipe(rec.SourceUrl) {
+		site, err := pageSiteName(rec.SiteName, rec.SourceUrl)
+		if err != nil {
+			return err
+		}
+		d.Source = &Source{SiteName: site}
+	}
+	ings, err := q.ListRecipeIngredients(ctx, recipeID)
+	if err != nil {
+		return fmt.Errorf("ingredients: %w", err)
+	}
+	for i, ing := range ings {
+		if i > 0 && ing.Position == ings[i-1].Position {
+			return duplicatePosition("ingredient", ing.Position)
+		}
+		d.Ingredients = append(d.Ingredients, Ingredient{
+			Name:    nullString(ing.Name),
+			Qty:     nullString(ing.Qty),
+			Unit:    nullString(ing.Unit),
+			Note:    nullString(ing.Note),
+			RawText: ing.RawText,
+		})
+	}
+	steps, err := q.ListRecipeSteps(ctx, recipeID)
+	if err != nil {
+		return fmt.Errorf("steps: %w", err)
+	}
+	for i, step := range steps {
+		if i > 0 && step.Position == steps[i-1].Position {
+			return duplicatePosition("step", step.Position)
+		}
+		d.Steps = append(d.Steps, step.Text)
+	}
+	return nil
+}
+
+// pageSiteName is the stored site name of a recipe fetched from sourceURL
+// when it is one the page gave, else nil. A page that names no site is
+// stored under recipes.HostSiteName of the URL it was served from: the
+// pasted link's host, which may hold a personal token (a private
+// subdomain), or that of a page the link redirected to, which is not
+// stored. Nothing records which a stored name is, so any name that could
+// be a host — the link's own host, an IP address, or a dotted host name —
+// is treated as one and withheld. A site that names itself as a domain,
+// such as "Food.com", loses its attribution with them: a recipe with no
+// attribution is better than one that leaks a link.
+func pageSiteName(stored sql.NullString, sourceURL string) (*string, error) {
+	if !stored.Valid {
+		return nil, nil
+	}
+	link, err := url.Parse(sourceURL)
+	if err != nil {
+		// Not wrapped: url.Parse's error quotes the link.
+		return nil, errors.New("source url does not parse")
+	}
+	name := stored.String
+	if strings.EqualFold(name, recipes.HostSiteName(link)) || net.ParseIP(name) != nil {
+		return nil, nil
+	}
+	if u, err := url.Parse("https://" + name + "/"); err == nil && u.Host == name && strings.Contains(name, ".") {
+		return nil, nil
+	}
+	return &name, nil
+}
+
+// duplicatePosition is the error for two recipe items of kind at position.
+// Position is the only record of recipe order, and the id that breaks the
+// tie says nothing about it, so a recipe with a duplicate is refused rather
+// than shown in an order nobody can trust.
+func duplicatePosition(kind string, position int64) error {
+	return fmt.Errorf("two %ss at position %d: recipe order is unknown", kind, position)
+}