package web

import (
	"time"

	"github.com/a-h/templ"

	"gitea.d-ma.be/mathias/tapir/internal/adapters/store"
)

// actionVerbs is the fixed, ordered set of action toggles rendered in the button
// group. It mirrors the store's allowed actions (store/actions.go); order here is
// the display order, not the store's.
var actionVerbs = []string{"watched", "skipped", "saved"}

// actionLabels maps each verb to its button caption.
var actionLabels = map[string]string{
	"watched": "Watched",
	"skipped": "Skipped",
	"saved":   "Saved",
}

func actionLabel(v string) string {
	if l, ok := actionLabels[v]; ok {
		return l
	}
	return v
}

// isActionVerb reports whether v is a known action verb. The handler rejects
// anything else before touching the store (defence in depth — the store also
// validates).
func isActionVerb(v string) bool {
	for _, a := range actionVerbs {
		if a == v {
			return true
		}
	}
	return false
}

// actionSet turns the store's active-action slice into a set for the template's
// O(1) "is this verb active?" lookups.
func actionSet(xs []string) map[string]bool {
	m := make(map[string]bool, len(xs))
	for _, x := range xs {
		m[x] = true
	}
	return m
}

func ariaPressed(b bool) string {
	if b {
		return "true"
	}
	return "false"
}

// displayTitle falls back to the video id when no videos row supplied a title
// (the LEFT JOIN can yield an empty Title — see store.SummaryRow).
func displayTitle(r store.SummaryRow) string {
	if r.Title != "" {
		return r.Title
	}
	return r.VideoID
}

// displayDate renders a published date, or an em dash when absent (zero time).
func displayDate(t time.Time) string {
	if t.IsZero() {
		return "—"
	}
	return t.Format("2006-01-02")
}

// videoURL builds the internal detail-page path for a video id.
func videoURL(videoID string) templ.SafeURL {
	return templ.SafeURL("/v/" + videoID)
}

// actionURL builds the action POST path for a video id.
func actionURL(videoID string) templ.SafeURL {
	return templ.SafeURL("/v/" + videoID + "/action")
}

// externalURL passes a stored source URL through templ's URL sanitiser.
func externalURL(u string) templ.SafeURL {
	return templ.URL(u)
}

// Filter holds the list-view query parameters. Empty fields mean "no constraint".
// Dates are kept as the raw YYYY-MM-DD strings so the form re-renders the user's
// input verbatim; parsing happens in matchFilter.
type Filter struct {
	Channel string
	From    string
	To      string
}

// matches reports whether a row satisfies the filter. Channel is an exact match;
// From/To bound PublishedAt inclusively. Unparseable or empty bounds are ignored
// (no constraint) — Stage-0 filtering is in-memory over the listed rows, not a
// store query.
func (f Filter) matches(r store.SummaryRow) bool {
	if f.Channel != "" && r.Channel != f.Channel {
		return false
	}
	if from, ok := parseDate(f.From); ok {
		if r.PublishedAt.IsZero() || r.PublishedAt.Before(from) {
			return false
		}
	}
	if to, ok := parseDate(f.To); ok {
		// inclusive of the whole "to" day
		if r.PublishedAt.IsZero() || r.PublishedAt.After(to.Add(24*time.Hour-time.Nanosecond)) {
			return false
		}
	}
	return true
}

func parseDate(s string) (time.Time, bool) {
	if s == "" {
		return time.Time{}, false
	}
	t, err := time.Parse("2006-01-02", s)
	if err != nil {
		return time.Time{}, false
	}
	return t, true
}

// apply returns the subset of rows matching the filter, preserving order.
func (f Filter) apply(rows []store.SummaryRow) []store.SummaryRow {
	if f == (Filter{}) {
		return rows
	}
	out := rows[:0:0]
	for _, r := range rows {
		if f.matches(r) {
			out = append(out, r)
		}
	}
	return out
}

// styleTag wraps the stylesheet in a <style> element, injected verbatim via
// templ.Raw (templ treats the body of a literal <style> element as opaque text,
// not as template expressions — so the CSS is rendered as a raw node instead).
var styleTag = "<style>" + stylesheet + "</style>"

const stylesheet = `
:root { color-scheme: light dark; --fg:#1a1a1a; --muted:#777; --line:#ddd; --accent:#2b6cb0; }
* { box-sizing: border-box; }
body { font: 15px/1.5 system-ui, sans-serif; margin: 0; color: var(--fg); }
header { padding: .75rem 1.25rem; border-bottom: 1px solid var(--line); }
.brand { font-weight: 700; text-decoration: none; color: var(--accent); }
main { max-width: 60rem; margin: 0 auto; padding: 1.25rem; }
table.summaries { width: 100%; border-collapse: collapse; }
table.summaries th, table.summaries td { text-align: left; padding: .5rem .6rem; border-bottom: 1px solid var(--line); vertical-align: top; }
table.summaries th { font-size: .8rem; text-transform: uppercase; letter-spacing: .03em; color: var(--muted); }
.empty { color: var(--muted); font-style: italic; }
.muted { color: var(--muted); }
.badge { display: inline-block; padding: 0 .4rem; border-radius: .4rem; background: #f0ad4e; color: #000; font-size: .75rem; }
.filters { display: flex; gap: 1rem; align-items: end; flex-wrap: wrap; margin-bottom: 1rem; }
.filters label { display: flex; flex-direction: column; font-size: .8rem; color: var(--muted); gap: .2rem; }
.filters input { font: inherit; padding: .25rem; }
.detail .meta { color: var(--muted); }
.actions { display: flex; gap: .5rem; margin: 1rem 0; }
.actions .action { font: inherit; padding: .4rem .8rem; border: 1px solid var(--line); border-radius: .4rem; background: transparent; cursor: pointer; }
.actions .action.active { background: var(--accent); color: #fff; border-color: var(--accent); }
.body { white-space: pre-wrap; }
`