package ingest

import (
	"encoding/json"
	"fmt"

	"textmachine/platform/internal/money"
)

// StatusReport is the ALLOWLISTED subset of `tmctl status --json` (pipeline.StatusReport) that the
// platform materializes. Everything absent here is absent on purpose: snapshot ids, drift, rebill,
// routing, content labels and the operator's flag taxonomy are engine vocabulary that must not
// cross the seam (contract §2.12), and unknown JSON fields are simply ignored by encoding/json.
type StatusReport struct {
	BookID     string `json:"book_id"`
	TotalUnits int    `json:"total_units"`
	Done       int    `json:"done"`
	InProgress int    `json:"in_progress"`
	Flagged    int    `json:"flagged"`
	Pending    int    `json:"pending"`
	// Progress is the PER-WAVE split of the same units, landed in the engine on 09.08 (D39.122;
	// pipeline.PhaseProgress). Taking it is what makes the resync channel as fine-grained as the
	// stream: without it a repair could restore only the aggregate, and folding one aggregate over a
	// projection the stream had already split REPLACED "draft 7/20 ∥ edit 1/20" with one number.
	// Same shape as the stream's own progress event, so both paths materialize through one type.
	Progress Progress `json:"progress"`
	// ETASeconds is what the owner asked to show (K-5); the engine already computes it.
	ETASeconds float64 `json:"eta_seconds"`
	// UnsignedBankTerms backs the signing screen's "N of M decided" while a stop is standing.
	UnsignedBankTerms int `json:"unsigned_bank_terms"`
	// Spend is the engine's committed spend, converted to integer micro-USD AT THE SEAM. The wire
	// value is a JSON decimal; binding it to a float64 would put drift one step before the integer
	// column that exists to prevent drift (PD-15). It is stored in the credit tables and NEVER
	// projected into an API response or an INFO log (D39.84).
	// A POINTER: absent, null and empty must not read as "the attempt cost nothing". A settlement
	// computed from a missing figure would release the whole hold and charge zero.
	Spend *money.MicroUSD `json:"committed_usd"`
	// Reserved is what the engine's OWN ledger has promised and not yet committed. It is NOT part of
	// the ceiling the platform computes — see runs.meter.bookCap: at spawn there is no other writer,
	// so anything reserved is a leftover of a dead process, and the engine's own write-open clears it
	// before judging anything. What this figure does is prove that reasoning holds, which is why the
	// spawn REQUIRES it and refuses without it.
	// A POINTER for the same reason Spend is one: absent, null and zero are three different facts.
	Reserved *money.MicroUSD `json:"reserved_usd"`
	Chapters []ChapterStatus `json:"chapters"`
}

// ChapterStatus is the per-chapter passport, allowlisted the same way (no cost, no verdict ranks).
//
// worst_flag_reason is deliberately NOT taken: contract v0 gives a chapter a note_count and nothing
// about the worst reason, so materializing it would store engine vocabulary no reader asks for
// (PD-19). It comes back with a column the day the chapter screen needs it.
type ChapterStatus struct {
	Chapter         int `json:"chapter"`
	UnitsTotal      int `json:"units_total"`
	UnitsDone       int `json:"units_done"`
	UnitsFlagged    int `json:"units_flagged"`
	UnitsInProgress int `json:"units_in_progress"`
	UnitsPending    int `json:"units_pending"`
}

// DecodeStatus parses a status report.
func DecodeStatus(b []byte) (StatusReport, error) {
	var r StatusReport
	if err := json.Unmarshal(b, &r); err != nil {
		return StatusReport{}, fmt.Errorf("ingest: decode status: %w", err)
	}
	return r, nil
}