package distillation

// Audit-FULL pipeline — Go port of scripts/distillation/audit_full.ts
// (Rust legacy). Runs the metric-collection passes that produce
// audit_baselines.jsonl entries. Pure observability: never modifies
// pipeline data, only reads and tallies.
//
// Phase coverage in this port:
//   - Phase 0 (file presence)            ✓ ported
//   - Phase 1 (schema validators)        ✗ skipped — Go's `go test`
//                                          equivalent runs as part of
//                                          `just verify`, no need to
//                                          re-invoke from here.
//   - Phase 2 (materializer dry-run)     ✗ deferred — depends on the
//                                          Go-side materializer port
//                                          (transforms + build_evidence
//                                          _index) which isn't yet
//                                          done. Surfaces as TODO.
//   - Phase 3 (scored-runs distribution) ✓ ported
//   - Phase 4 (contamination firewall)   ✓ ported
//   - Phase 5 (receipts validation)      ✗ deferred — depends on the
//                                          Go pipeline emitting
//                                          run-summary JSON, not yet.
//   - Phase 6 (replay sanity)            ✗ deferred — Go-side replay
//                                          tool not ported.
//   - Phase 7 (run summary lineage)      ✗ deferred — same.
//
// The phases that ARE ported are sufficient to produce the
// AuditBaseline metrics (p3_*, p4_*) that drift across runs. p2_*
// metrics will remain at zero until the materializer ports.
//
// Output: a structured PhaseCheckReport plus a Markdown summary.
// Operators run this from cmd/audit_full to validate a Go-side
// distillation pipeline run produced sane outputs.

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"regexp"
	"strings"
)

// PhaseCheck is one observable check within a phase. Mirrors the
// Rust shape exactly — Markdown rendering uses the same column
// layout so cross-runtime diff'ing is meaningful.
type PhaseCheck struct {
	Phase    int      `json:"phase"`
	Name     string   `json:"name"`
	Expected string   `json:"expected"`
	Actual   string   `json:"actual"`
	Passed   bool     `json:"passed"`
	Required bool     `json:"required"` // false → informational only, doesn't fail audit
	Notes    []string `json:"notes,omitempty"`
}

// PhaseCheckReport is the aggregate result of one audit-full run.
// Metrics is the AuditBaseline-shape metric snapshot that the
// caller can pass to AppendBaseline to grow the longitudinal log.
type PhaseCheckReport struct {
	Checks  []PhaseCheck     `json:"checks"`
	Metrics map[string]int64 `json:"metrics"`
	Failed  int              `json:"failed"`           // count of REQUIRED checks that failed
	Skipped int              `json:"deferred_phases"`  // phases not yet ported
	GitHEAD string           `json:"git_head,omitempty"`
}

// AuditFullOptions controls a single audit-full run. Root is the
// data dir (defaults to LH_DISTILL_ROOT or /home/profit/lakehouse
// to keep operators running both runtimes hitting the same paths).
type AuditFullOptions struct {
	Root    string
	GitHEAD string // optional — caller resolves and passes through
}

// RunAuditFull orchestrates the ported phases (0, 3, 4) and
// returns the aggregated report. Each phase is independent; a
// phase that errors is recorded as a failed check rather than
// aborting the run, matching Rust's "always emit a report" stance.
func RunAuditFull(opts AuditFullOptions) PhaseCheckReport {
	if opts.Root == "" {
		if env := os.Getenv("LH_DISTILL_ROOT"); env != "" {
			opts.Root = env
		} else {
			opts.Root = "/home/profit/lakehouse"
		}
	}
	report := PhaseCheckReport{
		Metrics: make(map[string]int64),
		GitHEAD: opts.GitHEAD,
		Skipped: 4, // phases 1, 2, 5, 6, 7 all skipped — see header comment
	}
	auditPhase0(opts.Root, &report)
	auditPhase3(opts.Root, &report)
	auditPhase4(opts.Root, &report)
	for _, c := range report.Checks {
		if c.Required && !c.Passed {
			report.Failed++
		}
	}
	return report
}

// ── Phase 0: file presence ─────────────────────────────────────────

func auditPhase0(root string, report *PhaseCheckReport) {
	// The recon doc is Rust-specific (docs/recon/local-distillation-
	// recon.md); a Go-side equivalent would live in the
	// golangLAKEHOUSE repo. For audit-full's purposes, we treat its
	// presence as informational rather than required when running
	// against a non-Rust root.
	reconPath := filepath.Join(root, "docs", "recon", "local-distillation-recon.md")
	exists := fileExists(reconPath)
	report.Checks = append(report.Checks, PhaseCheck{
		Phase: 0, Name: "recon doc exists",
		Expected: "docs/recon/local-distillation-recon.md present",
		Actual:   fmt.Sprintf("%v", exists),
		Passed:   exists, Required: false, // informational on Go-side runs
	})

	tier1 := []string{
		"data/_kb/distilled_facts.jsonl",
		"data/_kb/scrum_reviews.jsonl",
		"data/_kb/audit_facts.jsonl",
		"data/_kb/mode_experiments.jsonl",
	}
	missing := []string{}
	for _, p := range tier1 {
		if !fileExists(filepath.Join(root, p)) {
			missing = append(missing, p)
		}
	}
	notes := []string{}
	if len(missing) > 0 {
		notes = append(notes, "fresh-clone or post-rotation environment — Phase 2 will tally as rows_present=false; not a hard fail")
	}
	report.Checks = append(report.Checks, PhaseCheck{
		Phase: 0, Name: "tier-1 source streams present",
		Expected: "all 4 tier-1 jsonls on disk",
		Actual: func() string {
			if len(missing) == 0 {
				return "all present"
			}
			return "missing: " + strings.Join(missing, ", ")
		}(),
		Passed: len(missing) == 0, Required: false,
		Notes: notes,
	})
}

// ── Phase 3: scored-runs distribution ──────────────────────────────

func auditPhase3(root string, report *PhaseCheckReport) {
	scoredDir := filepath.Join(root, "data", "scored-runs")
	if !fileExists(scoredDir) {
		report.Checks = append(report.Checks, PhaseCheck{
			Phase: 3, Name: "scored-runs on disk",
			Expected: "data/scored-runs/ populated",
			Actual:   "missing",
			Passed:   false, Required: true,
			Notes: []string{"run scoring before audit-full (Go: scripts/distillation/score; Rust: ./scripts/distill score)"},
		})
		return
	}

	counts := map[string]int64{
		"accepted":           0,
		"partially_accepted": 0,
		"rejected":           0,
		"needs_human_review": 0,
	}
	files, err := ListScoredRunFiles(root)
	if err != nil {
		report.Checks = append(report.Checks, PhaseCheck{
			Phase: 3, Name: "scored-runs walk",
			Expected: "no error", Actual: err.Error(),
			Passed: false, Required: true,
		})
		return
	}
	for _, f := range files {
		runs, _, err := LoadScoredRunsFromFile(f)
		if err != nil {
			continue
		}
		for _, r := range runs {
			if _, ok := counts[string(r.Category)]; ok {
				counts[string(r.Category)]++
			}
		}
	}
	total := counts["accepted"] + counts["partially_accepted"] + counts["rejected"] + counts["needs_human_review"]

	report.Metrics["p3_accepted"] = counts["accepted"]
	report.Metrics["p3_partial"] = counts["partially_accepted"]
	report.Metrics["p3_rejected"] = counts["rejected"]
	report.Metrics["p3_human"] = counts["needs_human_review"]

	report.Checks = append(report.Checks, PhaseCheck{
		Phase: 3, Name: "on-disk scored-runs distribution non-empty",
		Expected: ">=1 accepted",
		Actual:   fmt.Sprintf("acc=%d part=%d rej=%d hum=%d", counts["accepted"], counts["partially_accepted"], counts["rejected"], counts["needs_human_review"]),
		Passed:   counts["accepted"] >= 1, Required: true,
	})
	report.Checks = append(report.Checks, PhaseCheck{
		Phase: 3, Name: "scored-runs distribution sums positive",
		Expected: ">0 total", Actual: fmt.Sprintf("%d total", total),
		Passed: total > 0, Required: false,
	})
}

// ── Phase 4: contamination firewall + provenance ───────────────────

// sigHashRe pre-compiled match for the canonical sig_hash shape:
// 64 lowercase hex characters (sha256 hex). Used per-row in the
// provenance check.
var sigHashRe = regexp.MustCompile(`^[0-9a-f]{64}$`)

func auditPhase4(root string, report *PhaseCheckReport) {
	sftPath := filepath.Join(root, "exports", "sft", "instruction_response.jsonl")
	ragPath := filepath.Join(root, "exports", "rag", "playbooks.jsonl")
	prefPath := filepath.Join(root, "exports", "preference", "chosen_rejected.jsonl")

	sftRows := readJSONLLines(sftPath)
	ragRows := readJSONLLines(ragPath)
	prefRows := readJSONLLines(prefPath)

	report.Metrics["p4_sft_rows"] = int64(len(sftRows))
	report.Metrics["p4_rag_rows"] = int64(len(ragRows))
	report.Metrics["p4_pref_pairs"] = int64(len(prefRows))

	// SFT contamination firewall: 0 forbidden quality_scores. The
	// only legal SFT quality scores are accepted + partially_accepted.
	sftForbidden := 0
	for _, line := range sftRows {
		var r struct {
			QualityScore string `json:"quality_score"`
		}
		if err := json.Unmarshal([]byte(line), &r); err != nil {
			continue // tolerate malformed (matches Rust)
		}
		if r.QualityScore != "accepted" && r.QualityScore != "partially_accepted" {
			sftForbidden++
		}
	}
	report.Checks = append(report.Checks, PhaseCheck{
		Phase: 4, Name: "SFT contamination firewall: 0 forbidden quality_scores",
		Expected: "0", Actual: fmt.Sprintf("%d", sftForbidden),
		Passed: sftForbidden == 0, Required: true,
		Notes: []string{"this is the spec non-negotiable — rejected/needs_human_review must NEVER appear in SFT"},
	})

	// RAG firewall: 0 rejected leaks
	ragRejected := 0
	for _, line := range ragRows {
		var r struct {
			SuccessScore string `json:"success_score"`
		}
		if err := json.Unmarshal([]byte(line), &r); err != nil {
			continue
		}
		if r.SuccessScore == "rejected" {
			ragRejected++
		}
	}
	report.Checks = append(report.Checks, PhaseCheck{
		Phase: 4, Name: "RAG firewall: 0 rejected leaks",
		Expected: "0", Actual: fmt.Sprintf("%d", ragRejected),
		Passed: ragRejected == 0, Required: true,
	})

	// Preference: 0 self-pairs + 0 identical-text pairs.
	prefSelfPairs, prefIdenticalText := 0, 0
	for _, line := range prefRows {
		var r struct {
			ChosenRunID   string `json:"chosen_run_id"`
			RejectedRunID string `json:"rejected_run_id"`
			Chosen        string `json:"chosen"`
			Rejected      string `json:"rejected"`
		}
		if err := json.Unmarshal([]byte(line), &r); err != nil {
			continue
		}
		if r.ChosenRunID == r.RejectedRunID {
			prefSelfPairs++
		}
		if r.Chosen == r.Rejected {
			prefIdenticalText++
		}
	}
	report.Checks = append(report.Checks, PhaseCheck{
		Phase: 4, Name: "Preference: 0 self-pairs (chosen_run_id != rejected_run_id)",
		Expected: "0", Actual: fmt.Sprintf("%d", prefSelfPairs),
		Passed: prefSelfPairs == 0, Required: true,
	})
	report.Checks = append(report.Checks, PhaseCheck{
		Phase: 4, Name: "Preference: 0 identical-text pairs",
		Expected: "0", Actual: fmt.Sprintf("%d", prefIdenticalText),
		Passed: prefIdenticalText == 0, Required: true,
	})

	// Provenance check: every export row must carry a 64-char hex
	// sig_hash. Walks sft + rag + pref together since the contract
	// is uniform across all three.
	noProv := 0
	checkProv := func(line string) {
		var r struct {
			Provenance struct {
				SigHash string `json:"sig_hash"`
			} `json:"provenance"`
		}
		if err := json.Unmarshal([]byte(line), &r); err != nil {
			return
		}
		if r.Provenance.SigHash == "" || !sigHashRe.MatchString(r.Provenance.SigHash) {
			noProv++
		}
	}
	for _, line := range sftRows {
		checkProv(line)
	}
	for _, line := range ragRows {
		checkProv(line)
	}
	for _, line := range prefRows {
		checkProv(line)
	}
	report.Checks = append(report.Checks, PhaseCheck{
		Phase: 4, Name: "every export row carries valid sha256 provenance.sig_hash",
		Expected: "0 missing", Actual: fmt.Sprintf("%d missing", noProv),
		Passed: noProv == 0, Required: true,
	})

	// Quarantine totals (informational — feeds the p4_total_quarantined
	// metric used by the longitudinal drift signal).
	totalQuar := int64(0)
	for _, qp := range []string{
		"exports/quarantine/sft.jsonl",
		"exports/quarantine/rag.jsonl",
		"exports/quarantine/preference.jsonl",
	} {
		totalQuar += int64(len(readJSONLLines(filepath.Join(root, qp))))
	}
	report.Metrics["p4_total_quarantined"] = totalQuar
}

// ── helpers ────────────────────────────────────────────────────────

func fileExists(p string) bool {
	_, err := os.Stat(p)
	return err == nil
}

// readJSONLLines reads a JSONL file and returns non-empty lines.
// Returns nil on missing file (matches Rust's existsSync ? read : []).
func readJSONLLines(path string) []string {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil
	}
	out := make([]string, 0)
	for _, line := range strings.Split(string(data), "\n") {
		if strings.TrimSpace(line) != "" {
			out = append(out, line)
		}
	}
	return out
}

// FormatAuditFullReport renders a Markdown report mirroring the
// Rust phase8-full-audit-report.md shape so operators reading
// across runtimes don't have to re-learn the layout.
func FormatAuditFullReport(report PhaseCheckReport) string {
	var b strings.Builder
	fmt.Fprintln(&b, "# Audit-FULL report (Go)")
	fmt.Fprintln(&b)
	if report.GitHEAD != "" {
		fmt.Fprintf(&b, "**git HEAD:** `%s`\n\n", report.GitHEAD)
	}
	failed := report.Failed
	total := 0
	for _, c := range report.Checks {
		if c.Required {
			total++
		}
	}
	verdict := "PASS"
	if failed > 0 {
		verdict = "FAIL"
	}
	fmt.Fprintf(&b, "**Verdict:** %s — %d/%d required checks passed; %d phase(s) deferred.\n\n",
		verdict, total-failed, total, report.Skipped)

	fmt.Fprintln(&b, "## Checks")
	fmt.Fprintln(&b)
	fmt.Fprintln(&b, "| phase | name | expected | actual | required | passed |")
	fmt.Fprintln(&b, "|---|---|---|---|---|---|")
	for _, c := range report.Checks {
		req := "no"
		if c.Required {
			req = "**yes**"
		}
		passed := "✗"
		if c.Passed {
			passed = "✓"
		}
		fmt.Fprintf(&b, "| %d | %s | %s | %s | %s | %s |\n",
			c.Phase, c.Name, c.Expected, c.Actual, req, passed)
		for _, n := range c.Notes {
			fmt.Fprintf(&b, "| | _note_ | %s | | | |\n", n)
		}
	}

	if len(report.Metrics) > 0 {
		fmt.Fprintln(&b)
		fmt.Fprintln(&b, "## Metrics")
		fmt.Fprintln(&b)
		fmt.Fprintln(&b, "| metric | value |")
		fmt.Fprintln(&b, "|---|---:|")
		// Stable order for diffs.
		names := make([]string, 0, len(report.Metrics))
		for k := range report.Metrics {
			names = append(names, k)
		}
		// sort imported via audit_baseline.go
		sortStrings(names)
		for _, k := range names {
			fmt.Fprintf(&b, "| %s | %d |\n", k, report.Metrics[k])
		}
	}
	return b.String()
}

// sortStrings is the local sort wrapper to keep imports tidy across
// audit_baseline.go and audit_full.go (both need string sorting;
// importing sort once at the package level is cleaner).
func sortStrings(s []string) {
	// Insertion sort — N is at most a dozen metric names.
	for i := 1; i < len(s); i++ {
		for j := i; j > 0 && s[j-1] > s[j]; j-- {
			s[j-1], s[j] = s[j], s[j-1]
		}
	}
}