package main

import (
	"cmp"
	_ "embed"
	"html/template"
	"log"
	"net/http"
	"strings"
	"time"

	"github.com/kami/maven/internal/ipc"
)

// The read-only pages: dash, history, trace, morning, events, and the voice
// page mounted at "/". Each is GET-only, reads through CoreAPI and renders.
// The write surfaces live next to their own handlers (tasks.go, tools.go,
// routines.go, chat.go).

//go:embed dash.html
var dashHTML string

//go:embed history.html
var historyHTML string

//go:embed trace.html
var traceHTML string

//go:embed morning.html
var morningHTML string

//go:embed events.html
var eventsHTML string

//go:embed voice.html
var voiceHTML string

//go:embed ecosystem.html
var ecosystemHTML string

// dashTmpl — the monitoring read surface, server-rendered from dash.html;
// a small fetch loop refreshes the tables in place. html/template escapes the
// user text in facts/nudges. Read-only: browses the append-only store via
// CoreAPI, never writes — the store IS the audit trail, this just shows it.
var dashTmpl = parsePage("dash", dashHTML, nil)

var historyTmpl = parsePage("history", historyHTML, nil)

var traceTmpl = parsePage("trace", traceHTML, template.FuncMap{
	"fmtTime": func(t *time.Time) string {
		if t == nil || t.IsZero() {
			return "—"
		}
		return t.Format("15:04:05")
	},
	"join": strings.Join,
})

// morningTmpl — read-only view of today's checklist state per configured
// morning routine (internal/morning). Same shape as trace.html: a plain
// server-rendered page, refreshed on reload — no live-update loop, since
// checklist state changes on the scale of minutes, not seconds.
var morningTmpl = parsePage("morning", morningHTML, nil)

// eventsTmpl — the unified intake journal (Vikunja #283), read-only. Same
// shape as trace.html and morning.html: server-rendered, refreshed on reload.
var eventsTmpl = parsePage("events", eventsHTML, nil)

var voiceTmpl = parsePage("voice", voiceHTML, nil)

// ecosystemTmpl — read-only view of the Nexus/Praxis/Hexis siblings, whose only
// human surface is here (they ship no web UI of their own).
var ecosystemTmpl = parsePage("ecosystem", ecosystemHTML, nil)

func handleDash(w http.ResponseWriter, r *http.Request, core ipc.CoreAPI) {
	if !requireCore(w, core, "dash") {
		return
	}
	ctx := r.Context()
	pres, err1 := core.Presence(ctx)
	facts, err2 := core.RecentFacts(ctx, 50)
	nudges, err3 := core.RecentNudges(ctx, 50)
	notes, err4 := core.RecentNotes(ctx, 50)
	if err := cmp.Or(err1, err2, err3, err4); err != nil {
		log.Printf("dash: %v", err)
		http.Error(w, "core read failed", http.StatusBadGateway)
		return
	}
	renderPage(w, dashTmpl, struct {
		Presence ipc.Presence
		Facts    []ipc.Fact
		Nudges   []ipc.Nudge
		Notes    []ipc.Note
	}{pres, facts, nudges, notes})
}

func handleHistory(w http.ResponseWriter, r *http.Request, core ipc.CoreAPI) {
	if !requireCore(w, core, "history") {
		return
	}
	facts, err := core.RecentFacts(r.Context(), 200)
	if err != nil {
		log.Printf("history: %v", err)
		http.Error(w, "core read failed", http.StatusBadGateway)
		return
	}
	renderPage(w, historyTmpl, struct {
		Facts []ipc.Fact
	}{facts})
}

func handleTrace(w http.ResponseWriter, r *http.Request, core ipc.CoreAPI) {
	if !requireCore(w, core, "trace") {
		return
	}
	trace, err := core.TickTrace(r.Context())
	if err != nil {
		log.Printf("trace: %v", err)
		http.Error(w, "core read failed", http.StatusBadGateway)
		return
	}
	// The turn records share this page rather than getting one of their own
	// (V-564). Both answer the same question, who won and who lost and why, and
	// one is about nudges while the other is about utterances. A read failure
	// here is not fatal to the page. The rule trace above it still renders, and
	// a daemon too old to know the method is the ordinary case during a rolling
	// deploy.
	turns, err := core.TurnDecisions(r.Context(), 25)
	if err != nil {
		log.Printf("trace: turn decisions: %v", err)
	}
	renderPage(w, traceTmpl, traceData{Tick: trace, Turns: turns})
}

// traceData — what trace.html renders: the last tick's rule arbitration and the
// last turns' claim arbitration.
type traceData struct {
	Tick  ipc.TickTrace
	Turns []ipc.TurnDecision
}

// morningView — what /morning renders: today's plan on top, the checklist
// state under it. PlanErr is set instead of Plan when the core could not build
// a plan, so the page says so rather than showing an empty day.
type morningView struct {
	Plan     *ipc.DayPlan
	PlanErr  string
	Routines []ipc.MorningRoutineStatus
}

func handleMorning(w http.ResponseWriter, r *http.Request, core ipc.CoreAPI) {
	if !requireCore(w, core, "morning") {
		return
	}
	ctx := r.Context()
	status, err := core.MorningStatus(ctx)
	if err != nil {
		log.Printf("morning: %v", err)
		http.Error(w, "core read failed", http.StatusBadGateway)
		return
	}
	view := morningView{Routines: status}
	// The day plan (#128) shows on this page because it is the same question at
	// a different scale. A plan read that fails must not take the checklist
	// down with it — the page degrades to what it had before.
	plan, err := core.DayPlan(ctx)
	if err != nil {
		log.Printf("morning: day plan: %v", err)
		view.PlanErr = err.Error()
	} else {
		view.Plan = &plan
	}
	renderPage(w, morningTmpl, view)
}

// eventsView — what /events renders. Err is set instead of Events when the
// core could not serve the journal, so the page says why rather than showing an
// empty intake and implying nothing arrived.
type eventsView struct {
	Events []ipc.IntakeEvent
	Err    string
}

// eventsPageLimit — how many envelopes the page shows. The ring holds more; a
// page is for scanning what just happened, not for archaeology.
const eventsPageLimit = 200

func handleEvents(w http.ResponseWriter, r *http.Request, core ipc.CoreAPI) {
	if !requireCore(w, core, "intake journal") {
		return
	}
	var view eventsView
	evs, err := core.RecentEvents(r.Context(), eventsPageLimit)
	if err != nil {
		log.Printf("events: %v", err)
		view.Err = err.Error()
	} else {
		view.Events = evs
	}
	renderPage(w, eventsTmpl, view)
}

func handleVoice(w http.ResponseWriter, r *http.Request) {
	renderPage(w, voiceTmpl, nil)
}