package session

import (
	"antidrift/internal/domain"
	"sort"
	"time"
)

// CommitmentView is the UI projection of the active commitment.
type CommitmentView struct {
	NextAction       string `json:"next_action"`
	SuccessCondition string `json:"success_condition"`
	TimeboxSecs      int64  `json:"timebox_secs"`
	DeadlineUnixSecs int64  `json:"deadline_unix_secs"`
}

// ProposalView / CoachView project the ephemeral planning-coach state.
type ProposalView struct {
	NextAction       string `json:"next_action"`
	SuccessCondition string `json:"success_condition"`
	TimeboxSecs      int64  `json:"timebox_secs"`

	AllowedWindowClasses []string `json:"allowed_window_classes,omitempty"`
}

// DriftView is the active-only drift projection. Nudge is a separate axis from
// Status: it is populated precisely when Status is "ontask" (semantic drift
// inside an allowed app), so it cannot be folded into the status enum.
type DriftView struct {
	Status   string `json:"status"`
	Reason   string `json:"reason,omitempty"`
	Nudge    string `json:"nudge,omitempty"`
	Enforced bool   `json:"enforced,omitempty"`
}

type CoachView struct {
	Status   string        `json:"status"`
	Proposal *ProposalView `json:"proposal,omitempty"`
	Error    string        `json:"error,omitempty"`
}

// TaskView is one to-do item in the planning tasks list.
type TaskView struct {
	ID    string `json:"id"`
	Title string `json:"title"`
	Day   string `json:"day,omitempty"`
}

// TasksView projects the ephemeral planning tasks state (Marvin's today list).
type TasksView struct {
	Status string     `json:"status"`
	Tasks  []TaskView `json:"tasks,omitempty"`
}

// KnowledgeView projects the ephemeral planning knowledge state (the standing
// profile that grounds the coach). The profile text is intentionally omitted —
// only its presence, source path, and size cross the wire.
type KnowledgeView struct {
	Status string `json:"status"`
	Path   string `json:"path,omitempty"`
	Chars  int    `json:"chars,omitempty"`
}

// ReflectionView projects the reviewer's output. Recap is shown on Review;
// CarryForward is shown on the next Planning screen. Unlike the knowledge
// profile, these short lines exist to be displayed, so they cross the wire.
type ReflectionView struct {
	Status       string `json:"status,omitempty"`
	Recap        string `json:"recap,omitempty"`
	CarryForward string `json:"carry_forward,omitempty"`
}

// WindowView / BucketView / EvidenceView are the evidence projection.
type WindowView struct {
	Class string `json:"class"`
	Title string `json:"title"`
}

type BucketView struct {
	Class   string `json:"class"`
	Title   string `json:"title"`
	Seconds int64  `json:"seconds"`
}

type EvidenceView struct {
	Available   bool         `json:"available"`
	Reason      string       `json:"reason"`
	Current     WindowView   `json:"current"`
	SwitchCount int          `json:"switch_count"`
	Buckets     []BucketView `json:"buckets"`
}

// State is the broadcastable view of the controller.
type State struct {
	RuntimeState domain.RuntimeState `json:"runtime_state"`
	Commitment   *CommitmentView     `json:"commitment"`
	Evidence     *EvidenceView       `json:"evidence"`
	Coach        *CoachView          `json:"coach,omitempty"`
	Tasks        *TasksView          `json:"tasks,omitempty"`
	Knowledge    *KnowledgeView      `json:"knowledge,omitempty"`
	Reflection   *ReflectionView     `json:"reflection,omitempty"`
	Drift        *DriftView          `json:"drift,omitempty"`
}

func (c *Controller) stateLocked() State {
	st := State{RuntimeState: c.runtimeState}
	if c.commitment != nil {
		view := &CommitmentView{
			NextAction:       c.commitment.NextAction,
			SuccessCondition: c.commitment.SuccessCondition,
			TimeboxSecs:      c.commitment.TimeboxSecs,
		}
		if !c.deadline.IsZero() {
			view.DeadlineUnixSecs = c.deadline.Unix()
		}
		st.Commitment = view
	}
	if c.stats != nil {
		st.Evidence = &EvidenceView{
			Available:   c.stats.Current.Health.Available,
			Reason:      c.stats.Current.Health.Reason,
			Current:     WindowView{Class: c.stats.Current.Class, Title: c.stats.Current.Title},
			SwitchCount: c.stats.SwitchCount,
			Buckets:     bucketViews(c.stats.Buckets),
		}
	}
	if c.runtimeState == domain.RuntimePlanning {
		// Surface the live window so planning can show the real class to copy into
		// the allowed-apps field — exact class names are otherwise invisible, and a
		// non-matching token silently disables the local on-task fast path.
		st.Evidence = &EvidenceView{
			Available: c.latestWindow.Health.Available,
			Reason:    c.latestWindow.Health.Reason,
			Current:   WindowView{Class: c.latestWindow.Class, Title: c.latestWindow.Title},
		}
		status := c.coachStatus
		if status == "" {
			status = coachIdle
		}
		cv := &CoachView{Status: status, Error: c.coachErr}
		if c.coachProposal != nil {
			cv.Proposal = &ProposalView{
				NextAction:           c.coachProposal.NextAction,
				SuccessCondition:     c.coachProposal.SuccessCondition,
				TimeboxSecs:          c.coachProposal.TimeboxSecs,
				AllowedWindowClasses: c.coachProposal.AllowedWindowClasses,
			}
		}
		st.Coach = cv
		if c.tasksProvider != nil {
			tstatus := c.tasksStatus
			if tstatus == "" {
				tstatus = tasksIdle
			}
			tv := &TasksView{Status: tstatus}
			for _, t := range c.tasksList {
				tv.Tasks = append(tv.Tasks, TaskView{ID: t.ID, Title: t.Title, Day: t.Day})
			}
			st.Tasks = tv
		}
		if c.knowledgeSrc != nil {
			kstatus := c.knowledgeStatus
			if kstatus == "" {
				kstatus = knowledgeIdle
			}
			st.Knowledge = &KnowledgeView{Status: kstatus, Path: c.knowledgePath, Chars: c.knowledgeChars}
		}
		if c.carryForward != "" {
			st.Reflection = &ReflectionView{CarryForward: c.carryForward}
		}
	}
	if c.runtimeState == domain.RuntimeReview {
		rstatus := c.reflectionStatus
		if rstatus == "" {
			rstatus = reflectionIdle
		}
		st.Reflection = &ReflectionView{Status: rstatus, Recap: c.reflectionRecap}
	}
	if c.runtimeState == domain.RuntimeActive {
		status := c.driftStatus
		if status == "" {
			status = driftIdle
		}
		enforced := c.enforcementLevel == domain.EnforcementBlock && c.driftStatus == driftDrifting
		st.Drift = &DriftView{Status: status, Reason: c.driftReason, Nudge: c.nudgeMessage, Enforced: enforced}
	}
	return st
}

func bucketViews(buckets map[bucketKey]time.Duration) []BucketView {
	out := make([]BucketView, 0, len(buckets))
	for k, d := range buckets {
		out = append(out, BucketView{Class: k.Class, Title: k.Title, Seconds: int64(d.Seconds())})
	}
	sort.Slice(out, func(i, j int) bool { return out[i].Seconds > out[j].Seconds })
	return out
}