package store

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"time"

	"vetting/internal/model"
)

type Runs struct {
	DB *sql.DB
}

func (r *Runs) Create(ctx context.Context, hostID int64, tokenHash string, nonDestructive bool) (int64, error) {
	now := time.Now().UTC()
	nd := 0
	if nonDestructive {
		nd = 1
	}
	res, err := r.DB.ExecContext(ctx, `
		INSERT INTO runs(host_id, state, agent_token_hash, next_boot_target, started_at, non_destructive)
		VALUES(?,?,?,?,?,?)
	`, hostID, string(model.StateQueued), tokenHash, "linux", now, nd)
	if err != nil {
		return 0, fmt.Errorf("insert run: %w", err)
	}
	return res.LastInsertId()
}

func (r *Runs) SetState(ctx context.Context, runID int64, state model.RunState) error {
	_, err := r.DB.ExecContext(ctx, `UPDATE runs SET state = ? WHERE id = ?`, string(state), runID)
	return err
}

// RotateTokenHash replaces the stored token hash. Called on each iPXE
// fetch so only the most-recently-booted agent can claim the run.
func (r *Runs) RotateTokenHash(ctx context.Context, runID int64, hash string) error {
	_, err := r.DB.ExecContext(ctx, `UPDATE runs SET agent_token_hash = ? WHERE id = ?`, hash, runID)
	return err
}

// SetHoldIP records the agent's LAN IP so the UI can show the ssh
// command. Called when the agent POSTs /hold.
func (r *Runs) SetHoldIP(ctx context.Context, runID int64, ip string) error {
	_, err := r.DB.ExecContext(ctx, `UPDATE runs SET hold_ip = ? WHERE id = ?`, ip, runID)
	return err
}

// SetFailedStage records which stage tripped the run; used by the tile
// and by reports. Does not change state.
func (r *Runs) SetFailedStage(ctx context.Context, runID int64, stage string) error {
	_, err := r.DB.ExecContext(ctx, `UPDATE runs SET failed_stage = ? WHERE id = ?`, stage, runID)
	return err
}

// ClearFailedStage wipes the failed_stage marker. Called when the
// operator overrides a stage and the run re-enters the pipeline.
func (r *Runs) ClearFailedStage(ctx context.Context, runID int64) error {
	_, err := r.DB.ExecContext(ctx, `UPDATE runs SET failed_stage = NULL WHERE id = ?`, runID)
	return err
}

// SetOverrideFlags persists the operator's override decisions (JSON blob
// like `{"wipe":true}`). Passed back to the agent on the next heartbeat
// so it can resume the held stage with the gate bypassed.
func (r *Runs) SetOverrideFlags(ctx context.Context, runID int64, flagsJSON string) error {
	_, err := r.DB.ExecContext(ctx, `UPDATE runs SET override_flags_json = ? WHERE id = ?`, flagsJSON, runID)
	return err
}

func (r *Runs) MarkFailed(ctx context.Context, runID int64, failedStage, holdIP string) error {
	now := time.Now().UTC()
	_, err := r.DB.ExecContext(ctx, `
		UPDATE runs SET state = ?, result = 'fail', failed_stage = ?, hold_ip = ?, completed_at = ?
		WHERE id = ?
	`, string(model.StateFailedHolding), failedStage, holdIP, now, runID)
	return err
}

// MarkDispatchFailed records a terminal failure discovered before the run
// ever reached a live image, e.g. the dispatcher refused to start because
// the host isn't heartbeating. Goes to StateFailed (not FailedHolding)
// because there's no live image to ssh into.
func (r *Runs) MarkDispatchFailed(ctx context.Context, runID int64, failedStage, result string) error {
	now := time.Now().UTC()
	_, err := r.DB.ExecContext(ctx, `
		UPDATE runs SET state = ?, result = ?, failed_stage = ?, completed_at = ?
		WHERE id = ?
	`, string(model.StateFailed), result, failedStage, now, runID)
	return err
}

func (r *Runs) MarkCompleted(ctx context.Context, runID int64, reportPath string) error {
	now := time.Now().UTC()
	_, err := r.DB.ExecContext(ctx, `
		UPDATE runs SET state = ?, result = 'pass', report_path = ?, completed_at = ?
		WHERE id = ?
	`, string(model.StateCompleted), reportPath, now, runID)
	return err
}

func (r *Runs) Get(ctx context.Context, id int64) (*model.Run, error) {
	row := r.DB.QueryRowContext(ctx, `
		SELECT id, host_id, state, COALESCE(result,''), COALESCE(failed_stage,''),
		       COALESCE(next_boot_target,''), agent_token_hash, started_at,
		       completed_at, COALESCE(report_path,''), COALESCE(hold_ip,''),
		       COALESCE(override_flags_json,''), COALESCE(non_destructive,0)
		FROM runs WHERE id = ?
	`, id)
	var run model.Run
	var completedAt sql.NullTime
	err := row.Scan(&run.ID, &run.HostID, &run.State, &run.Result, &run.FailedStage,
		&run.NextBootTarget, &run.AgentTokenHash, &run.StartedAt,
		&completedAt, &run.ReportPath, &run.HoldIP, &run.OverrideFlagsJSON, &run.NonDestructive)
	if errors.Is(err, sql.ErrNoRows) {
		return nil, ErrNotFound
	}
	if err != nil {
		return nil, fmt.Errorf("get run: %w", err)
	}
	if completedAt.Valid {
		run.CompletedAt = &completedAt.Time
	}
	return &run, nil
}

// LatestForHost returns the most recent run for a host, or nil if none.
func (r *Runs) LatestForHost(ctx context.Context, hostID int64) (*model.Run, error) {
	row := r.DB.QueryRowContext(ctx, `
		SELECT id, host_id, state, COALESCE(result,''), COALESCE(failed_stage,''),
		       COALESCE(next_boot_target,''), agent_token_hash, started_at,
		       completed_at, COALESCE(report_path,''), COALESCE(hold_ip,''),
		       COALESCE(override_flags_json,''), COALESCE(non_destructive,0)
		FROM runs WHERE host_id = ?
		ORDER BY id DESC LIMIT 1
	`, hostID)
	var run model.Run
	var completedAt sql.NullTime
	err := row.Scan(&run.ID, &run.HostID, &run.State, &run.Result, &run.FailedStage,
		&run.NextBootTarget, &run.AgentTokenHash, &run.StartedAt,
		&completedAt, &run.ReportPath, &run.HoldIP, &run.OverrideFlagsJSON, &run.NonDestructive)
	if errors.Is(err, sql.ErrNoRows) {
		return nil, nil
	}
	if err != nil {
		return nil, fmt.Errorf("latest run: %w", err)
	}
	if completedAt.Valid {
		run.CompletedAt = &completedAt.Time
	}
	return &run, nil
}

// ListForHost returns the most recent `limit` runs for a host, newest
// first. Zero/negative limit falls back to a safe cap so a mistaken call
// can't scan the whole history into memory.
func (r *Runs) ListForHost(ctx context.Context, hostID int64, limit int) ([]model.Run, error) {
	if limit <= 0 {
		limit = 20
	}
	rows, err := r.DB.QueryContext(ctx, `
		SELECT id, host_id, state, COALESCE(result,''), COALESCE(failed_stage,''),
		       COALESCE(next_boot_target,''), agent_token_hash, started_at,
		       completed_at, COALESCE(report_path,''), COALESCE(hold_ip,''),
		       COALESCE(override_flags_json,''), COALESCE(non_destructive,0)
		FROM runs
		WHERE host_id = ?
		ORDER BY id DESC
		LIMIT ?
	`, hostID, limit)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var out []model.Run
	for rows.Next() {
		var run model.Run
		var completedAt sql.NullTime
		if err := rows.Scan(&run.ID, &run.HostID, &run.State, &run.Result, &run.FailedStage,
			&run.NextBootTarget, &run.AgentTokenHash, &run.StartedAt,
			&completedAt, &run.ReportPath, &run.HoldIP, &run.OverrideFlagsJSON, &run.NonDestructive); err != nil {
			return nil, err
		}
		if completedAt.Valid {
			run.CompletedAt = &completedAt.Time
		}
		out = append(out, run)
	}
	return out, rows.Err()
}

// ListForHostAll returns every run for a host, newest first. Caps at a
// defensive 1000 rows so a runaway host that somehow accumulated tens
// of thousands of runs doesn't blow up the page load; typical hosts
// finish with < 50.
func (r *Runs) ListForHostAll(ctx context.Context, hostID int64) ([]model.Run, error) {
	return r.ListForHost(ctx, hostID, 1000)
}

// Active returns all runs in non-terminal states.
func (r *Runs) Active(ctx context.Context) ([]model.Run, error) {
	rows, err := r.DB.QueryContext(ctx, `
		SELECT id, host_id, state, COALESCE(result,''), COALESCE(failed_stage,''),
		       COALESCE(next_boot_target,''), agent_token_hash, started_at,
		       completed_at, COALESCE(report_path,''), COALESCE(hold_ip,''),
		       COALESCE(override_flags_json,''), COALESCE(non_destructive,0)
		FROM runs
		WHERE state NOT IN ('Completed','Released','Cancelled')
		ORDER BY id
	`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var out []model.Run
	for rows.Next() {
		var run model.Run
		var completedAt sql.NullTime
		if err := rows.Scan(&run.ID, &run.HostID, &run.State, &run.Result, &run.FailedStage,
			&run.NextBootTarget, &run.AgentTokenHash, &run.StartedAt,
			&completedAt, &run.ReportPath, &run.HoldIP, &run.OverrideFlagsJSON, &run.NonDestructive); err != nil {
			return nil, err
		}
		if completedAt.Valid {
			run.CompletedAt = &completedAt.Time
		}
		out = append(out, run)
	}
	return out, rows.Err()
}

// CompletedOlderThan returns run IDs for terminal (Completed/Released/
// FailedHolding) runs whose completed_at is older than cutoff. Runs with
// a NULL completed_at fall back to started_at so a stuck run doesn't get
// garbage-collected out from under its own logs. Used by the janitor.
func (r *Runs) CompletedOlderThan(ctx context.Context, cutoff time.Time) ([]int64, error) {
	rows, err := r.DB.QueryContext(ctx, `
		SELECT id FROM runs
		WHERE state IN ('Completed','Released','FailedHolding','Cancelled')
		  AND COALESCE(completed_at, started_at) < ?
		ORDER BY id
	`, cutoff)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var out []int64
	for rows.Next() {
		var id int64
		if err := rows.Scan(&id); err != nil {
			return nil, err
		}
		out = append(out, id)
	}
	return out, rows.Err()
}

// FindByMAC returns the current active run for the host with the given MAC,
// or nil if the MAC is unknown or has no active run.
func (r *Runs) FindActiveByMAC(ctx context.Context, mac string) (*model.Run, error) {
	row := r.DB.QueryRowContext(ctx, `
		SELECT r.id, r.host_id, r.state, COALESCE(r.result,''), COALESCE(r.failed_stage,''),
		       COALESCE(r.next_boot_target,''), r.agent_token_hash, r.started_at,
		       r.completed_at, COALESCE(r.report_path,''), COALESCE(r.hold_ip,''),
		       COALESCE(r.override_flags_json,''), COALESCE(r.non_destructive,0)
		FROM runs r
		JOIN hosts h ON h.id = r.host_id
		WHERE h.mac = ? AND r.state NOT IN ('Completed','Released','Cancelled')
		ORDER BY r.id DESC LIMIT 1
	`, mac)
	var run model.Run
	var completedAt sql.NullTime
	err := row.Scan(&run.ID, &run.HostID, &run.State, &run.Result, &run.FailedStage,
		&run.NextBootTarget, &run.AgentTokenHash, &run.StartedAt,
		&completedAt, &run.ReportPath, &run.HoldIP, &run.OverrideFlagsJSON, &run.NonDestructive)
	if errors.Is(err, sql.ErrNoRows) {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}
	if completedAt.Valid {
		run.CompletedAt = &completedAt.Time
	}
	return &run, nil
}