// Package models defines the core data structures shared across the app.
// These are plain Go structs — no ORM tags, no magic.
package models

import (
	"time"

	"github.com/google/uuid"
)

// ── Database models (match table columns exactly) ─────────────────────────────

type Receipt struct {
	ID          uuid.UUID  `json:"id"`
	StoreName   *string    `json:"store_name"`
	ReceiptDate time.Time  `json:"receipt_date"`
	ImageURL    *string    `json:"image_url"`
	City        *string    `json:"city"`
	SubmittedAt time.Time  `json:"submitted_at"`
}

type LineItem struct {
	ID            uuid.UUID `json:"id"`
	ReceiptID     uuid.UUID `json:"receipt_id"`
	RawName       string    `json:"raw_name"`
	CanonicalName *string   `json:"canonical_name"`
	Category      *string   `json:"category"`
	PriceCents    int       `json:"price_cents"`
	Quantity      float64   `json:"quantity"`
}

type PriceSnapshot struct {
	CanonicalName string    `json:"canonical_name"`
	YearMonth     time.Time `json:"year_month"`
	AvgPriceCents int       `json:"avg_price_cents"`
	SampleCount   int       `json:"sample_count"`
}

type PriceMover struct {
	CanonicalName     string  `json:"canonical_name"`
	CurrentPriceCents int     `json:"current_price_cents"`
	PrevPriceCents    int     `json:"prev_price_cents"`
	PctChange         float64 `json:"pct_change"`
}

type InflationSummary struct {
	FromDate        time.Time `json:"from_date"`
	ToDate          time.Time `json:"to_date"`
	PurchasingPower float64   `json:"purchasing_power"` // e.g. 58.3 means $1 → $0.583
	ItemCount       int       `json:"item_count"`
}

// ── Insert params (what the API layer passes to db.Queries) ───────────────────

type InsertReceiptParams struct {
	StoreName   *string
	ReceiptDate time.Time
	ImageURL    *string
	City        *string
}

type InsertLineItemParams struct {
	ReceiptID     uuid.UUID
	RawName       string
	CanonicalName *string
	Category      *string
	PriceCents    int
	Quantity      float64
}

// ── API request/response shapes ───────────────────────────────────────────────

// SubmitReceiptRequest is the JSON body (or form data) for POST /api/receipts
type SubmitReceiptRequest struct {
	StoreName   string     `json:"store_name"`
	ReceiptDate string     `json:"receipt_date"` // ISO 8601: "2024-03-15"
	City        string     `json:"city"`
	Items       []ItemInput `json:"items"`
}

type ItemInput struct {
	Name     string  `json:"name"`       // raw name as on the receipt
	Price    float64 `json:"price"`      // in dollars, e.g. 3.99
	Quantity float64 `json:"quantity"`   // default 1
}

// SubmitReceiptResponse is returned after a successful submission
type SubmitReceiptResponse struct {
	ReceiptID  uuid.UUID  `json:"receipt_id"`
	ItemsAdded int        `json:"items_added"`
	Message    string     `json:"message"`
}

// PriceHistoryResponse is returned by GET /api/items/:name/history
type PriceHistoryResponse struct {
	CanonicalName string          `json:"canonical_name"`
	DataPoints    []PriceDataPoint `json:"data_points"`
}

type PriceDataPoint struct {
	Month       string  `json:"month"`        // "2024-03"
	AvgPrice    float64 `json:"avg_price"`    // in dollars
	SampleCount int     `json:"sample_count"`
}

// ErrorResponse is the standard shape for all API errors
type ErrorResponse struct {
	Error   string `json:"error"`
	Details string `json:"details,omitempty"`
}