package store

import (
	"context"
	"errors"
	"time"

	"github.com/jackc/pgx/v5"
)

// The wire shapes below are what the frontend already expected from the
// previous stack, so the view layer never learned about the schema and does
// not have to now.

type Creator struct {
	Name     string `json:"name"`
	Initials string `json:"initials"`
	Location string `json:"location"`
	Blurb    string `json:"blurb"`
	// Empty when the owner has no photo. The client falls back to Initials,
	// so this is omitted from the payload rather than sent as "".
	AvatarURL string `json:"avatarUrl,omitempty"`
}

type StorySection struct {
	Heading string   `json:"heading"`
	Body    []string `json:"body"`
}

type Tier struct {
	ID                string   `json:"id"`
	Type              string   `json:"type"`
	Price             int      `json:"price"`
	ListPrice         *int     `json:"listPrice,omitempty"`
	Title             string   `json:"title"`
	Includes          []string `json:"includes"`
	Backers           int      `json:"backers"`
	InventoryLimit    *int     `json:"inventoryLimit,omitempty"`
	EstimatedDelivery string   `json:"estimatedDelivery,omitempty"`
	Featured          bool     `json:"featured"`
}

type CampaignSummary struct {
	Slug     string  `json:"slug"`
	Title    string  `json:"title"`
	Category string  `json:"category"`
	Summary  string  `json:"summary"`
	Art      string  `json:"art"`
	Creator  Creator `json:"creator"`
	Goal     int     `json:"goal"`
	Raised   int     `json:"raised"`
	Backers  int     `json:"backers"`
	EndsAt   string  `json:"endsAt"`
	Status   string  `json:"status"`
}

type Campaign struct {
	CampaignSummary
	Story    []StorySection `json:"story"`
	Tiers    []Tier         `json:"tiers"`
	Updates  int            `json:"updates"`
	Comments int            `json:"comments"`
}

var ErrNotFound = errors.New("not found")

// Only these statuses are visible without an admin session. A draft campaign
// must 404 for the public exactly as a non-existent one does.
var publicStatuses = []string{"AKTIV", "FINANSZIROZOTT", "LEZART"}

// A pledge counts towards the total once the card is authorized; released and
// refunded pledges drop back out. The raised amount and the backer count are
// ALWAYS derived from these rows and stored nowhere.
var countedPledges = []string{"AUTHORIZED", "CAPTURED"}

var statusOut = map[string]string{
	"AKTIV":          "aktiv",
	"FINANSZIROZOTT": "finanszirozott",
	"LEZART":         "lezart",
}

var tierTypeOut = map[string]string{
	"DONATION": "donation",
	"DIGITAL":  "digital",
	"PHYSICAL": "physical",
}

func outStatus(s string) string {
	if v, ok := statusOut[s]; ok {
		return v
	}
	return "aktiv"
}

func outTierType(s string) string {
	if v, ok := tierTypeOut[s]; ok {
		return v
	}
	return "donation"
}

const listSQL = `
SELECT c."slug", c."title", c."category", c."summary", c."art",
       o."name", o."initials", o."location", o."blurb", COALESCE(o."avatarUrl", ''),
       c."goalAmount", c."endsAt", c."status"::text,
       COALESCE(p."total", 0)::int, COALESCE(p."backers", 0)::int
FROM "Campaign" c
JOIN "Owner" o ON o."id" = c."ownerId"
LEFT JOIN (
    SELECT "campaignId", SUM("amount") AS "total", COUNT(*) AS "backers"
    FROM "Pledge"
    WHERE "status" = ANY($2::"PledgeStatus"[])
    GROUP BY "campaignId"
) p ON p."campaignId" = c."id"
WHERE c."status" = ANY($1::"CampaignStatus"[])
ORDER BY c."status" ASC, c."endsAt" ASC`

func (s *Store) ListCampaigns(ctx context.Context) ([]CampaignSummary, error) {
	rows, err := s.pool.Query(ctx, listSQL, publicStatuses, countedPledges)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	out := []CampaignSummary{}
	for rows.Next() {
		var c CampaignSummary
		var endsAt time.Time
		var status string
		if err := rows.Scan(
			&c.Slug, &c.Title, &c.Category, &c.Summary, &c.Art,
			&c.Creator.Name, &c.Creator.Initials, &c.Creator.Location, &c.Creator.Blurb,
			&c.Creator.AvatarURL,
			&c.Goal, &endsAt, &status, &c.Raised, &c.Backers,
		); err != nil {
			return nil, err
		}
		c.EndsAt = s.Day(endsAt)
		c.Status = outStatus(status)
		out = append(out, c)
	}
	return out, rows.Err()
}

const campaignSQL = `
SELECT c."id", c."slug", c."title", c."category", c."summary", c."art",
       o."name", o."initials", o."location", o."blurb", COALESCE(o."avatarUrl", ''),
       c."goalAmount", c."endsAt", c."status"::text,
       COALESCE(p."total", 0)::int, COALESCE(p."backers", 0)::int,
       (SELECT COUNT(*) FROM "CampaignUpdate" u WHERE u."campaignId" = c."id")::int,
       (SELECT COUNT(*) FROM "Comment" m WHERE m."campaignId" = c."id")::int
FROM "Campaign" c
JOIN "Owner" o ON o."id" = c."ownerId"
LEFT JOIN (
    SELECT "campaignId", SUM("amount") AS "total", COUNT(*) AS "backers"
    FROM "Pledge"
    WHERE "status" = ANY($3::"PledgeStatus"[])
    GROUP BY "campaignId"
) p ON p."campaignId" = c."id"
WHERE c."slug" = $1 AND c."status" = ANY($2::"CampaignStatus"[])`

const tiersSQL = `
SELECT t."id", t."type"::text, t."price", t."listPrice", t."title", t."includes",
       t."inventoryLimit", t."estimatedDelivery", t."featured",
       COALESCE(p."backers", 0)::int
FROM "RewardTier" t
LEFT JOIN (
    SELECT "tierId", COUNT(*) AS "backers"
    FROM "Pledge"
    WHERE "campaignId" = $1 AND "status" = ANY($2::"PledgeStatus"[])
    GROUP BY "tierId"
) p ON p."tierId" = t."id"
WHERE t."campaignId" = $1
ORDER BY t."position" ASC`

// GetCampaignBySlug returns a campaign the public may see, or ErrNotFound.
func (s *Store) GetCampaignBySlug(ctx context.Context, slug string) (*Campaign, error) {
	var c Campaign
	var id string
	var endsAt time.Time
	var status string

	err := s.pool.QueryRow(ctx, campaignSQL, slug, publicStatuses, countedPledges).Scan(
		&id, &c.Slug, &c.Title, &c.Category, &c.Summary, &c.Art,
		&c.Creator.Name, &c.Creator.Initials, &c.Creator.Location, &c.Creator.Blurb,
		&c.Creator.AvatarURL,
		&c.Goal, &endsAt, &status, &c.Raised, &c.Backers, &c.Updates, &c.Comments,
	)
	if errors.Is(err, pgx.ErrNoRows) {
		return nil, ErrNotFound
	}
	if err != nil {
		return nil, err
	}
	c.EndsAt = s.Day(endsAt)
	c.Status = outStatus(status)

	c.Story, err = s.storySections(ctx, id)
	if err != nil {
		return nil, err
	}

	rows, err := s.pool.Query(ctx, tiersSQL, id, countedPledges)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	c.Tiers = []Tier{}
	for rows.Next() {
		var t Tier
		var kind string
		var delivery *time.Time
		if err := rows.Scan(&t.ID, &kind, &t.Price, &t.ListPrice, &t.Title, &t.Includes,
			&t.InventoryLimit, &delivery, &t.Featured, &t.Backers); err != nil {
			return nil, err
		}
		t.Type = outTierType(kind)
		if delivery != nil {
			t.EstimatedDelivery = s.Day(*delivery)
		}
		c.Tiers = append(c.Tiers, t)
	}
	return &c, rows.Err()
}

func (s *Store) storySections(ctx context.Context, campaignID string) ([]StorySection, error) {
	rows, err := s.pool.Query(ctx,
		`SELECT "heading", "body" FROM "StorySection" WHERE "campaignId" = $1 ORDER BY "position" ASC`,
		campaignID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	out := []StorySection{}
	for rows.Next() {
		var sec StorySection
		if err := rows.Scan(&sec.Heading, &sec.Body); err != nil {
			return nil, err
		}
		out = append(out, sec)
	}
	return out, rows.Err()
}

type PlatformStats struct {
	ActiveCount int `json:"activeCount"`
	Backers     int `json:"backers"`
}

func (s *Store) PlatformStats(ctx context.Context) (PlatformStats, error) {
	var st PlatformStats
	err := s.pool.QueryRow(ctx, `
		SELECT (SELECT COUNT(*) FROM "Campaign" WHERE "status" = 'AKTIV')::int,
		       (SELECT COUNT(*) FROM "Pledge" WHERE "status" = ANY($1::"PledgeStatus"[]))::int`,
		countedPledges).Scan(&st.ActiveCount, &st.Backers)
	return st, err
}